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f65fd747 | 1 | /* Malloc implementation for multiple threads without lock contention. |
5290baf0 | 2 | Copyright (C) 1996, 1997 Free Software Foundation, Inc. |
f65fd747 | 3 | This file is part of the GNU C Library. |
6259ec0d UD |
4 | Contributed by Wolfram Gloger <wmglo@dent.med.uni-muenchen.de> |
5 | and Doug Lea <dl@cs.oswego.edu>, 1996. | |
f65fd747 UD |
6 | |
7 | The GNU C Library is free software; you can redistribute it and/or | |
8 | modify it under the terms of the GNU Library General Public License as | |
9 | published by the Free Software Foundation; either version 2 of the | |
10 | License, or (at your option) any later version. | |
11 | ||
12 | The GNU C Library is distributed in the hope that it will be useful, | |
13 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
15 | Library General Public License for more details. | |
16 | ||
17 | You should have received a copy of the GNU Library General Public | |
18 | License along with the GNU C Library; see the file COPYING.LIB. If not, | |
19 | write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, | |
20 | Boston, MA 02111-1307, USA. */ | |
21 | ||
2f6d1f1b | 22 | /* V2.6.4-pt3 Thu Feb 20 1997 |
f65fd747 UD |
23 | |
24 | This work is mainly derived from malloc-2.6.4 by Doug Lea | |
25 | <dl@cs.oswego.edu>, which is available from: | |
26 | ||
27 | ftp://g.oswego.edu/pub/misc/malloc.c | |
28 | ||
29 | Most of the original comments are reproduced in the code below. | |
30 | ||
31 | * Why use this malloc? | |
32 | ||
33 | This is not the fastest, most space-conserving, most portable, or | |
34 | most tunable malloc ever written. However it is among the fastest | |
35 | while also being among the most space-conserving, portable and tunable. | |
36 | Consistent balance across these factors results in a good general-purpose | |
37 | allocator. For a high-level description, see | |
38 | http://g.oswego.edu/dl/html/malloc.html | |
39 | ||
40 | On many systems, the standard malloc implementation is by itself not | |
41 | thread-safe, and therefore wrapped with a single global lock around | |
42 | all malloc-related functions. In some applications, especially with | |
43 | multiple available processors, this can lead to contention problems | |
44 | and bad performance. This malloc version was designed with the goal | |
45 | to avoid waiting for locks as much as possible. Statistics indicate | |
46 | that this goal is achieved in many cases. | |
47 | ||
48 | * Synopsis of public routines | |
49 | ||
50 | (Much fuller descriptions are contained in the program documentation below.) | |
51 | ||
52 | ptmalloc_init(); | |
53 | Initialize global configuration. When compiled for multiple threads, | |
54 | this function must be called once before any other function in the | |
10dc2a90 UD |
55 | package. It is not required otherwise. It is called automatically |
56 | in the Linux/GNU C libray or when compiling with MALLOC_HOOKS. | |
f65fd747 UD |
57 | malloc(size_t n); |
58 | Return a pointer to a newly allocated chunk of at least n bytes, or null | |
59 | if no space is available. | |
60 | free(Void_t* p); | |
61 | Release the chunk of memory pointed to by p, or no effect if p is null. | |
62 | realloc(Void_t* p, size_t n); | |
63 | Return a pointer to a chunk of size n that contains the same data | |
64 | as does chunk p up to the minimum of (n, p's size) bytes, or null | |
65 | if no space is available. The returned pointer may or may not be | |
66 | the same as p. If p is null, equivalent to malloc. Unless the | |
67 | #define REALLOC_ZERO_BYTES_FREES below is set, realloc with a | |
68 | size argument of zero (re)allocates a minimum-sized chunk. | |
69 | memalign(size_t alignment, size_t n); | |
70 | Return a pointer to a newly allocated chunk of n bytes, aligned | |
71 | in accord with the alignment argument, which must be a power of | |
72 | two. | |
73 | valloc(size_t n); | |
74 | Equivalent to memalign(pagesize, n), where pagesize is the page | |
75 | size of the system (or as near to this as can be figured out from | |
76 | all the includes/defines below.) | |
77 | pvalloc(size_t n); | |
78 | Equivalent to valloc(minimum-page-that-holds(n)), that is, | |
79 | round up n to nearest pagesize. | |
80 | calloc(size_t unit, size_t quantity); | |
81 | Returns a pointer to quantity * unit bytes, with all locations | |
82 | set to zero. | |
83 | cfree(Void_t* p); | |
84 | Equivalent to free(p). | |
85 | malloc_trim(size_t pad); | |
86 | Release all but pad bytes of freed top-most memory back | |
87 | to the system. Return 1 if successful, else 0. | |
88 | malloc_usable_size(Void_t* p); | |
89 | Report the number usable allocated bytes associated with allocated | |
90 | chunk p. This may or may not report more bytes than were requested, | |
91 | due to alignment and minimum size constraints. | |
92 | malloc_stats(); | |
93 | Prints brief summary statistics on stderr. | |
94 | mallinfo() | |
95 | Returns (by copy) a struct containing various summary statistics. | |
96 | mallopt(int parameter_number, int parameter_value) | |
97 | Changes one of the tunable parameters described below. Returns | |
98 | 1 if successful in changing the parameter, else 0. | |
99 | ||
100 | * Vital statistics: | |
101 | ||
102 | Alignment: 8-byte | |
103 | 8 byte alignment is currently hardwired into the design. This | |
104 | seems to suffice for all current machines and C compilers. | |
105 | ||
106 | Assumed pointer representation: 4 or 8 bytes | |
107 | Code for 8-byte pointers is untested by me but has worked | |
108 | reliably by Wolfram Gloger, who contributed most of the | |
109 | changes supporting this. | |
110 | ||
111 | Assumed size_t representation: 4 or 8 bytes | |
112 | Note that size_t is allowed to be 4 bytes even if pointers are 8. | |
113 | ||
114 | Minimum overhead per allocated chunk: 4 or 8 bytes | |
115 | Each malloced chunk has a hidden overhead of 4 bytes holding size | |
116 | and status information. | |
117 | ||
118 | Minimum allocated size: 4-byte ptrs: 16 bytes (including 4 overhead) | |
119 | 8-byte ptrs: 24/32 bytes (including, 4/8 overhead) | |
120 | ||
121 | When a chunk is freed, 12 (for 4byte ptrs) or 20 (for 8 byte | |
122 | ptrs but 4 byte size) or 24 (for 8/8) additional bytes are | |
123 | needed; 4 (8) for a trailing size field | |
124 | and 8 (16) bytes for free list pointers. Thus, the minimum | |
125 | allocatable size is 16/24/32 bytes. | |
126 | ||
127 | Even a request for zero bytes (i.e., malloc(0)) returns a | |
128 | pointer to something of the minimum allocatable size. | |
129 | ||
130 | Maximum allocated size: 4-byte size_t: 2^31 - 8 bytes | |
131 | 8-byte size_t: 2^63 - 16 bytes | |
132 | ||
133 | It is assumed that (possibly signed) size_t bit values suffice to | |
134 | represent chunk sizes. `Possibly signed' is due to the fact | |
135 | that `size_t' may be defined on a system as either a signed or | |
136 | an unsigned type. To be conservative, values that would appear | |
137 | as negative numbers are avoided. | |
138 | Requests for sizes with a negative sign bit will return a | |
139 | minimum-sized chunk. | |
140 | ||
141 | Maximum overhead wastage per allocated chunk: normally 15 bytes | |
142 | ||
6d52618b | 143 | Alignment demands, plus the minimum allocatable size restriction |
f65fd747 UD |
144 | make the normal worst-case wastage 15 bytes (i.e., up to 15 |
145 | more bytes will be allocated than were requested in malloc), with | |
146 | two exceptions: | |
147 | 1. Because requests for zero bytes allocate non-zero space, | |
148 | the worst case wastage for a request of zero bytes is 24 bytes. | |
149 | 2. For requests >= mmap_threshold that are serviced via | |
150 | mmap(), the worst case wastage is 8 bytes plus the remainder | |
151 | from a system page (the minimal mmap unit); typically 4096 bytes. | |
152 | ||
153 | * Limitations | |
154 | ||
155 | Here are some features that are NOT currently supported | |
156 | ||
f65fd747 UD |
157 | * No automated mechanism for fully checking that all accesses |
158 | to malloced memory stay within their bounds. | |
159 | * No support for compaction. | |
160 | ||
161 | * Synopsis of compile-time options: | |
162 | ||
163 | People have reported using previous versions of this malloc on all | |
164 | versions of Unix, sometimes by tweaking some of the defines | |
165 | below. It has been tested most extensively on Solaris and | |
166 | Linux. People have also reported adapting this malloc for use in | |
167 | stand-alone embedded systems. | |
168 | ||
169 | The implementation is in straight, hand-tuned ANSI C. Among other | |
170 | consequences, it uses a lot of macros. Because of this, to be at | |
171 | all usable, this code should be compiled using an optimizing compiler | |
172 | (for example gcc -O2) that can simplify expressions and control | |
173 | paths. | |
174 | ||
175 | __STD_C (default: derived from C compiler defines) | |
176 | Nonzero if using ANSI-standard C compiler, a C++ compiler, or | |
177 | a C compiler sufficiently close to ANSI to get away with it. | |
178 | MALLOC_DEBUG (default: NOT defined) | |
179 | Define to enable debugging. Adds fairly extensive assertion-based | |
180 | checking to help track down memory errors, but noticeably slows down | |
181 | execution. | |
7e3be507 | 182 | MALLOC_HOOKS (default: NOT defined) |
10dc2a90 UD |
183 | Define to enable support run-time replacement of the allocation |
184 | functions through user-defined `hooks'. | |
f65fd747 UD |
185 | REALLOC_ZERO_BYTES_FREES (default: NOT defined) |
186 | Define this if you think that realloc(p, 0) should be equivalent | |
187 | to free(p). Otherwise, since malloc returns a unique pointer for | |
188 | malloc(0), so does realloc(p, 0). | |
189 | HAVE_MEMCPY (default: defined) | |
190 | Define if you are not otherwise using ANSI STD C, but still | |
191 | have memcpy and memset in your C library and want to use them. | |
192 | Otherwise, simple internal versions are supplied. | |
193 | USE_MEMCPY (default: 1 if HAVE_MEMCPY is defined, 0 otherwise) | |
194 | Define as 1 if you want the C library versions of memset and | |
195 | memcpy called in realloc and calloc (otherwise macro versions are used). | |
196 | At least on some platforms, the simple macro versions usually | |
197 | outperform libc versions. | |
198 | HAVE_MMAP (default: defined as 1) | |
199 | Define to non-zero to optionally make malloc() use mmap() to | |
200 | allocate very large blocks. | |
201 | HAVE_MREMAP (default: defined as 0 unless Linux libc set) | |
202 | Define to non-zero to optionally make realloc() use mremap() to | |
203 | reallocate very large blocks. | |
204 | malloc_getpagesize (default: derived from system #includes) | |
205 | Either a constant or routine call returning the system page size. | |
206 | HAVE_USR_INCLUDE_MALLOC_H (default: NOT defined) | |
207 | Optionally define if you are on a system with a /usr/include/malloc.h | |
208 | that declares struct mallinfo. It is not at all necessary to | |
209 | define this even if you do, but will ensure consistency. | |
210 | INTERNAL_SIZE_T (default: size_t) | |
211 | Define to a 32-bit type (probably `unsigned int') if you are on a | |
212 | 64-bit machine, yet do not want or need to allow malloc requests of | |
213 | greater than 2^31 to be handled. This saves space, especially for | |
214 | very small chunks. | |
215 | _LIBC (default: NOT defined) | |
216 | Defined only when compiled as part of the Linux libc/glibc. | |
217 | Also note that there is some odd internal name-mangling via defines | |
218 | (for example, internally, `malloc' is named `mALLOc') needed | |
219 | when compiling in this case. These look funny but don't otherwise | |
220 | affect anything. | |
221 | LACKS_UNISTD_H (default: undefined) | |
222 | Define this if your system does not have a <unistd.h>. | |
223 | MORECORE (default: sbrk) | |
224 | The name of the routine to call to obtain more memory from the system. | |
225 | MORECORE_FAILURE (default: -1) | |
226 | The value returned upon failure of MORECORE. | |
227 | MORECORE_CLEARS (default 1) | |
228 | True (1) if the routine mapped to MORECORE zeroes out memory (which | |
229 | holds for sbrk). | |
230 | DEFAULT_TRIM_THRESHOLD | |
231 | DEFAULT_TOP_PAD | |
232 | DEFAULT_MMAP_THRESHOLD | |
233 | DEFAULT_MMAP_MAX | |
234 | Default values of tunable parameters (described in detail below) | |
235 | controlling interaction with host system routines (sbrk, mmap, etc). | |
236 | These values may also be changed dynamically via mallopt(). The | |
237 | preset defaults are those that give best performance for typical | |
238 | programs/systems. | |
10dc2a90 UD |
239 | DEFAULT_CHECK_ACTION |
240 | When the standard debugging hooks are in place, and a pointer is | |
241 | detected as corrupt, do nothing (0), print an error message (1), | |
242 | or call abort() (2). | |
f65fd747 UD |
243 | |
244 | ||
245 | */ | |
246 | ||
247 | /* | |
248 | ||
249 | * Compile-time options for multiple threads: | |
250 | ||
251 | USE_PTHREADS, USE_THR, USE_SPROC | |
252 | Define one of these as 1 to select the thread interface: | |
253 | POSIX threads, Solaris threads or SGI sproc's, respectively. | |
254 | If none of these is defined as non-zero, you get a `normal' | |
255 | malloc implementation which is not thread-safe. Support for | |
256 | multiple threads requires HAVE_MMAP=1. As an exception, when | |
257 | compiling for GNU libc, i.e. when _LIBC is defined, then none of | |
258 | the USE_... symbols have to be defined. | |
259 | ||
260 | HEAP_MIN_SIZE | |
261 | HEAP_MAX_SIZE | |
262 | When thread support is enabled, additional `heap's are created | |
263 | with mmap calls. These are limited in size; HEAP_MIN_SIZE should | |
264 | be a multiple of the page size, while HEAP_MAX_SIZE must be a power | |
265 | of two for alignment reasons. HEAP_MAX_SIZE should be at least | |
266 | twice as large as the mmap threshold. | |
267 | THREAD_STATS | |
268 | When this is defined as non-zero, some statistics on mutex locking | |
269 | are computed. | |
270 | ||
271 | */ | |
272 | ||
273 | \f | |
274 | ||
275 | ||
f65fd747 UD |
276 | /* Preliminaries */ |
277 | ||
278 | #ifndef __STD_C | |
279 | #if defined (__STDC__) | |
280 | #define __STD_C 1 | |
281 | #else | |
282 | #if __cplusplus | |
283 | #define __STD_C 1 | |
284 | #else | |
285 | #define __STD_C 0 | |
286 | #endif /*__cplusplus*/ | |
287 | #endif /*__STDC__*/ | |
288 | #endif /*__STD_C*/ | |
289 | ||
290 | #ifndef Void_t | |
291 | #if __STD_C | |
292 | #define Void_t void | |
293 | #else | |
294 | #define Void_t char | |
295 | #endif | |
296 | #endif /*Void_t*/ | |
297 | ||
298 | #if __STD_C | |
10dc2a90 | 299 | # include <stddef.h> /* for size_t */ |
dfd2257a | 300 | # if defined _LIBC || defined MALLOC_HOOKS |
7e3be507 | 301 | # include <stdlib.h> /* for getenv(), abort() */ |
10dc2a90 | 302 | # endif |
f65fd747 | 303 | #else |
10dc2a90 | 304 | # include <sys/types.h> |
f65fd747 UD |
305 | #endif |
306 | ||
8a4b65b4 UD |
307 | /* Macros for handling mutexes and thread-specific data. This is |
308 | included early, because some thread-related header files (such as | |
309 | pthread.h) should be included before any others. */ | |
310 | #include "thread-m.h" | |
311 | ||
f65fd747 UD |
312 | #ifdef __cplusplus |
313 | extern "C" { | |
314 | #endif | |
315 | ||
316 | #include <stdio.h> /* needed for malloc_stats */ | |
317 | ||
318 | ||
319 | /* | |
320 | Compile-time options | |
321 | */ | |
322 | ||
323 | ||
324 | /* | |
325 | Debugging: | |
326 | ||
327 | Because freed chunks may be overwritten with link fields, this | |
328 | malloc will often die when freed memory is overwritten by user | |
329 | programs. This can be very effective (albeit in an annoying way) | |
330 | in helping track down dangling pointers. | |
331 | ||
332 | If you compile with -DMALLOC_DEBUG, a number of assertion checks are | |
333 | enabled that will catch more memory errors. You probably won't be | |
334 | able to make much sense of the actual assertion errors, but they | |
335 | should help you locate incorrectly overwritten memory. The | |
336 | checking is fairly extensive, and will slow down execution | |
337 | noticeably. Calling malloc_stats or mallinfo with MALLOC_DEBUG set will | |
338 | attempt to check every non-mmapped allocated and free chunk in the | |
6d52618b | 339 | course of computing the summaries. (By nature, mmapped regions |
f65fd747 UD |
340 | cannot be checked very much automatically.) |
341 | ||
342 | Setting MALLOC_DEBUG may also be helpful if you are trying to modify | |
343 | this code. The assertions in the check routines spell out in more | |
344 | detail the assumptions and invariants underlying the algorithms. | |
345 | ||
346 | */ | |
347 | ||
348 | #if MALLOC_DEBUG | |
349 | #include <assert.h> | |
350 | #else | |
351 | #define assert(x) ((void)0) | |
352 | #endif | |
353 | ||
354 | ||
355 | /* | |
356 | INTERNAL_SIZE_T is the word-size used for internal bookkeeping | |
357 | of chunk sizes. On a 64-bit machine, you can reduce malloc | |
358 | overhead by defining INTERNAL_SIZE_T to be a 32 bit `unsigned int' | |
359 | at the expense of not being able to handle requests greater than | |
360 | 2^31. This limitation is hardly ever a concern; you are encouraged | |
361 | to set this. However, the default version is the same as size_t. | |
362 | */ | |
363 | ||
364 | #ifndef INTERNAL_SIZE_T | |
365 | #define INTERNAL_SIZE_T size_t | |
366 | #endif | |
367 | ||
368 | /* | |
369 | REALLOC_ZERO_BYTES_FREES should be set if a call to | |
370 | realloc with zero bytes should be the same as a call to free. | |
371 | Some people think it should. Otherwise, since this malloc | |
372 | returns a unique pointer for malloc(0), so does realloc(p, 0). | |
373 | */ | |
374 | ||
375 | ||
376 | /* #define REALLOC_ZERO_BYTES_FREES */ | |
377 | ||
378 | ||
379 | /* | |
380 | HAVE_MEMCPY should be defined if you are not otherwise using | |
381 | ANSI STD C, but still have memcpy and memset in your C library | |
382 | and want to use them in calloc and realloc. Otherwise simple | |
383 | macro versions are defined here. | |
384 | ||
385 | USE_MEMCPY should be defined as 1 if you actually want to | |
386 | have memset and memcpy called. People report that the macro | |
387 | versions are often enough faster than libc versions on many | |
388 | systems that it is better to use them. | |
389 | ||
390 | */ | |
391 | ||
10dc2a90 | 392 | #define HAVE_MEMCPY 1 |
f65fd747 UD |
393 | |
394 | #ifndef USE_MEMCPY | |
395 | #ifdef HAVE_MEMCPY | |
396 | #define USE_MEMCPY 1 | |
397 | #else | |
398 | #define USE_MEMCPY 0 | |
399 | #endif | |
400 | #endif | |
401 | ||
402 | #if (__STD_C || defined(HAVE_MEMCPY)) | |
403 | ||
404 | #if __STD_C | |
405 | void* memset(void*, int, size_t); | |
406 | void* memcpy(void*, const void*, size_t); | |
407 | #else | |
408 | Void_t* memset(); | |
409 | Void_t* memcpy(); | |
410 | #endif | |
411 | #endif | |
412 | ||
413 | #if USE_MEMCPY | |
414 | ||
415 | /* The following macros are only invoked with (2n+1)-multiples of | |
416 | INTERNAL_SIZE_T units, with a positive integer n. This is exploited | |
417 | for fast inline execution when n is small. */ | |
418 | ||
419 | #define MALLOC_ZERO(charp, nbytes) \ | |
420 | do { \ | |
421 | INTERNAL_SIZE_T mzsz = (nbytes); \ | |
422 | if(mzsz <= 9*sizeof(mzsz)) { \ | |
423 | INTERNAL_SIZE_T* mz = (INTERNAL_SIZE_T*) (charp); \ | |
424 | if(mzsz >= 5*sizeof(mzsz)) { *mz++ = 0; \ | |
425 | *mz++ = 0; \ | |
426 | if(mzsz >= 7*sizeof(mzsz)) { *mz++ = 0; \ | |
427 | *mz++ = 0; \ | |
428 | if(mzsz >= 9*sizeof(mzsz)) { *mz++ = 0; \ | |
429 | *mz++ = 0; }}} \ | |
430 | *mz++ = 0; \ | |
431 | *mz++ = 0; \ | |
432 | *mz = 0; \ | |
433 | } else memset((charp), 0, mzsz); \ | |
434 | } while(0) | |
435 | ||
436 | #define MALLOC_COPY(dest,src,nbytes) \ | |
437 | do { \ | |
438 | INTERNAL_SIZE_T mcsz = (nbytes); \ | |
439 | if(mcsz <= 9*sizeof(mcsz)) { \ | |
440 | INTERNAL_SIZE_T* mcsrc = (INTERNAL_SIZE_T*) (src); \ | |
441 | INTERNAL_SIZE_T* mcdst = (INTERNAL_SIZE_T*) (dest); \ | |
442 | if(mcsz >= 5*sizeof(mcsz)) { *mcdst++ = *mcsrc++; \ | |
443 | *mcdst++ = *mcsrc++; \ | |
444 | if(mcsz >= 7*sizeof(mcsz)) { *mcdst++ = *mcsrc++; \ | |
445 | *mcdst++ = *mcsrc++; \ | |
446 | if(mcsz >= 9*sizeof(mcsz)) { *mcdst++ = *mcsrc++; \ | |
447 | *mcdst++ = *mcsrc++; }}} \ | |
448 | *mcdst++ = *mcsrc++; \ | |
449 | *mcdst++ = *mcsrc++; \ | |
450 | *mcdst = *mcsrc ; \ | |
451 | } else memcpy(dest, src, mcsz); \ | |
452 | } while(0) | |
453 | ||
454 | #else /* !USE_MEMCPY */ | |
455 | ||
456 | /* Use Duff's device for good zeroing/copying performance. */ | |
457 | ||
458 | #define MALLOC_ZERO(charp, nbytes) \ | |
459 | do { \ | |
460 | INTERNAL_SIZE_T* mzp = (INTERNAL_SIZE_T*)(charp); \ | |
461 | long mctmp = (nbytes)/sizeof(INTERNAL_SIZE_T), mcn; \ | |
462 | if (mctmp < 8) mcn = 0; else { mcn = (mctmp-1)/8; mctmp %= 8; } \ | |
463 | switch (mctmp) { \ | |
464 | case 0: for(;;) { *mzp++ = 0; \ | |
465 | case 7: *mzp++ = 0; \ | |
466 | case 6: *mzp++ = 0; \ | |
467 | case 5: *mzp++ = 0; \ | |
468 | case 4: *mzp++ = 0; \ | |
469 | case 3: *mzp++ = 0; \ | |
470 | case 2: *mzp++ = 0; \ | |
471 | case 1: *mzp++ = 0; if(mcn <= 0) break; mcn--; } \ | |
472 | } \ | |
473 | } while(0) | |
474 | ||
475 | #define MALLOC_COPY(dest,src,nbytes) \ | |
476 | do { \ | |
477 | INTERNAL_SIZE_T* mcsrc = (INTERNAL_SIZE_T*) src; \ | |
478 | INTERNAL_SIZE_T* mcdst = (INTERNAL_SIZE_T*) dest; \ | |
479 | long mctmp = (nbytes)/sizeof(INTERNAL_SIZE_T), mcn; \ | |
480 | if (mctmp < 8) mcn = 0; else { mcn = (mctmp-1)/8; mctmp %= 8; } \ | |
481 | switch (mctmp) { \ | |
482 | case 0: for(;;) { *mcdst++ = *mcsrc++; \ | |
483 | case 7: *mcdst++ = *mcsrc++; \ | |
484 | case 6: *mcdst++ = *mcsrc++; \ | |
485 | case 5: *mcdst++ = *mcsrc++; \ | |
486 | case 4: *mcdst++ = *mcsrc++; \ | |
487 | case 3: *mcdst++ = *mcsrc++; \ | |
488 | case 2: *mcdst++ = *mcsrc++; \ | |
489 | case 1: *mcdst++ = *mcsrc++; if(mcn <= 0) break; mcn--; } \ | |
490 | } \ | |
491 | } while(0) | |
492 | ||
493 | #endif | |
494 | ||
495 | ||
496 | /* | |
497 | Define HAVE_MMAP to optionally make malloc() use mmap() to | |
498 | allocate very large blocks. These will be returned to the | |
499 | operating system immediately after a free(). | |
500 | */ | |
501 | ||
502 | #ifndef HAVE_MMAP | |
503 | #define HAVE_MMAP 1 | |
504 | #endif | |
505 | ||
506 | /* | |
507 | Define HAVE_MREMAP to make realloc() use mremap() to re-allocate | |
508 | large blocks. This is currently only possible on Linux with | |
509 | kernel versions newer than 1.3.77. | |
510 | */ | |
511 | ||
512 | #ifndef HAVE_MREMAP | |
d71b808a | 513 | #define HAVE_MREMAP defined(__linux__) && !defined(__arm__) |
f65fd747 UD |
514 | #endif |
515 | ||
516 | #if HAVE_MMAP | |
517 | ||
518 | #include <unistd.h> | |
519 | #include <fcntl.h> | |
520 | #include <sys/mman.h> | |
521 | ||
522 | #if !defined(MAP_ANONYMOUS) && defined(MAP_ANON) | |
523 | #define MAP_ANONYMOUS MAP_ANON | |
524 | #endif | |
525 | ||
526 | #endif /* HAVE_MMAP */ | |
527 | ||
528 | /* | |
529 | Access to system page size. To the extent possible, this malloc | |
530 | manages memory from the system in page-size units. | |
531 | ||
532 | The following mechanics for getpagesize were adapted from | |
533 | bsd/gnu getpagesize.h | |
534 | */ | |
535 | ||
536 | #ifndef LACKS_UNISTD_H | |
537 | # include <unistd.h> | |
538 | #endif | |
539 | ||
540 | #ifndef malloc_getpagesize | |
541 | # ifdef _SC_PAGESIZE /* some SVR4 systems omit an underscore */ | |
542 | # ifndef _SC_PAGE_SIZE | |
543 | # define _SC_PAGE_SIZE _SC_PAGESIZE | |
544 | # endif | |
545 | # endif | |
546 | # ifdef _SC_PAGE_SIZE | |
547 | # define malloc_getpagesize sysconf(_SC_PAGE_SIZE) | |
548 | # else | |
549 | # if defined(BSD) || defined(DGUX) || defined(HAVE_GETPAGESIZE) | |
550 | extern size_t getpagesize(); | |
551 | # define malloc_getpagesize getpagesize() | |
552 | # else | |
553 | # include <sys/param.h> | |
554 | # ifdef EXEC_PAGESIZE | |
555 | # define malloc_getpagesize EXEC_PAGESIZE | |
556 | # else | |
557 | # ifdef NBPG | |
558 | # ifndef CLSIZE | |
559 | # define malloc_getpagesize NBPG | |
560 | # else | |
561 | # define malloc_getpagesize (NBPG * CLSIZE) | |
562 | # endif | |
563 | # else | |
564 | # ifdef NBPC | |
565 | # define malloc_getpagesize NBPC | |
566 | # else | |
567 | # ifdef PAGESIZE | |
568 | # define malloc_getpagesize PAGESIZE | |
569 | # else | |
570 | # define malloc_getpagesize (4096) /* just guess */ | |
571 | # endif | |
572 | # endif | |
573 | # endif | |
574 | # endif | |
575 | # endif | |
576 | # endif | |
577 | #endif | |
578 | ||
579 | ||
580 | ||
581 | /* | |
582 | ||
583 | This version of malloc supports the standard SVID/XPG mallinfo | |
584 | routine that returns a struct containing the same kind of | |
585 | information you can get from malloc_stats. It should work on | |
586 | any SVID/XPG compliant system that has a /usr/include/malloc.h | |
587 | defining struct mallinfo. (If you'd like to install such a thing | |
588 | yourself, cut out the preliminary declarations as described above | |
589 | and below and save them in a malloc.h file. But there's no | |
590 | compelling reason to bother to do this.) | |
591 | ||
592 | The main declaration needed is the mallinfo struct that is returned | |
593 | (by-copy) by mallinfo(). The SVID/XPG malloinfo struct contains a | |
594 | bunch of fields, most of which are not even meaningful in this | |
595 | version of malloc. Some of these fields are are instead filled by | |
596 | mallinfo() with other numbers that might possibly be of interest. | |
597 | ||
598 | HAVE_USR_INCLUDE_MALLOC_H should be set if you have a | |
599 | /usr/include/malloc.h file that includes a declaration of struct | |
600 | mallinfo. If so, it is included; else an SVID2/XPG2 compliant | |
601 | version is declared below. These must be precisely the same for | |
602 | mallinfo() to work. | |
603 | ||
604 | */ | |
605 | ||
606 | /* #define HAVE_USR_INCLUDE_MALLOC_H */ | |
607 | ||
608 | #if HAVE_USR_INCLUDE_MALLOC_H | |
8a4b65b4 | 609 | # include "/usr/include/malloc.h" |
f65fd747 | 610 | #else |
8a4b65b4 UD |
611 | # ifdef _LIBC |
612 | # include "malloc.h" | |
613 | # else | |
614 | # include "ptmalloc.h" | |
615 | # endif | |
f65fd747 UD |
616 | #endif |
617 | ||
618 | ||
619 | ||
620 | #ifndef DEFAULT_TRIM_THRESHOLD | |
621 | #define DEFAULT_TRIM_THRESHOLD (128 * 1024) | |
622 | #endif | |
623 | ||
624 | /* | |
625 | M_TRIM_THRESHOLD is the maximum amount of unused top-most memory | |
626 | to keep before releasing via malloc_trim in free(). | |
627 | ||
628 | Automatic trimming is mainly useful in long-lived programs. | |
629 | Because trimming via sbrk can be slow on some systems, and can | |
630 | sometimes be wasteful (in cases where programs immediately | |
631 | afterward allocate more large chunks) the value should be high | |
632 | enough so that your overall system performance would improve by | |
633 | releasing. | |
634 | ||
635 | The trim threshold and the mmap control parameters (see below) | |
636 | can be traded off with one another. Trimming and mmapping are | |
637 | two different ways of releasing unused memory back to the | |
638 | system. Between these two, it is often possible to keep | |
639 | system-level demands of a long-lived program down to a bare | |
640 | minimum. For example, in one test suite of sessions measuring | |
641 | the XF86 X server on Linux, using a trim threshold of 128K and a | |
642 | mmap threshold of 192K led to near-minimal long term resource | |
643 | consumption. | |
644 | ||
645 | If you are using this malloc in a long-lived program, it should | |
646 | pay to experiment with these values. As a rough guide, you | |
647 | might set to a value close to the average size of a process | |
648 | (program) running on your system. Releasing this much memory | |
649 | would allow such a process to run in memory. Generally, it's | |
831372e7 | 650 | worth it to tune for trimming rather than memory mapping when a |
f65fd747 UD |
651 | program undergoes phases where several large chunks are |
652 | allocated and released in ways that can reuse each other's | |
653 | storage, perhaps mixed with phases where there are no such | |
654 | chunks at all. And in well-behaved long-lived programs, | |
655 | controlling release of large blocks via trimming versus mapping | |
656 | is usually faster. | |
657 | ||
658 | However, in most programs, these parameters serve mainly as | |
659 | protection against the system-level effects of carrying around | |
660 | massive amounts of unneeded memory. Since frequent calls to | |
661 | sbrk, mmap, and munmap otherwise degrade performance, the default | |
662 | parameters are set to relatively high values that serve only as | |
663 | safeguards. | |
664 | ||
665 | The default trim value is high enough to cause trimming only in | |
666 | fairly extreme (by current memory consumption standards) cases. | |
667 | It must be greater than page size to have any useful effect. To | |
668 | disable trimming completely, you can set to (unsigned long)(-1); | |
669 | ||
670 | ||
671 | */ | |
672 | ||
673 | ||
674 | #ifndef DEFAULT_TOP_PAD | |
675 | #define DEFAULT_TOP_PAD (0) | |
676 | #endif | |
677 | ||
678 | /* | |
679 | M_TOP_PAD is the amount of extra `padding' space to allocate or | |
680 | retain whenever sbrk is called. It is used in two ways internally: | |
681 | ||
682 | * When sbrk is called to extend the top of the arena to satisfy | |
683 | a new malloc request, this much padding is added to the sbrk | |
684 | request. | |
685 | ||
686 | * When malloc_trim is called automatically from free(), | |
687 | it is used as the `pad' argument. | |
688 | ||
689 | In both cases, the actual amount of padding is rounded | |
690 | so that the end of the arena is always a system page boundary. | |
691 | ||
692 | The main reason for using padding is to avoid calling sbrk so | |
693 | often. Having even a small pad greatly reduces the likelihood | |
694 | that nearly every malloc request during program start-up (or | |
695 | after trimming) will invoke sbrk, which needlessly wastes | |
696 | time. | |
697 | ||
698 | Automatic rounding-up to page-size units is normally sufficient | |
699 | to avoid measurable overhead, so the default is 0. However, in | |
700 | systems where sbrk is relatively slow, it can pay to increase | |
701 | this value, at the expense of carrying around more memory than | |
702 | the program needs. | |
703 | ||
704 | */ | |
705 | ||
706 | ||
707 | #ifndef DEFAULT_MMAP_THRESHOLD | |
708 | #define DEFAULT_MMAP_THRESHOLD (128 * 1024) | |
709 | #endif | |
710 | ||
711 | /* | |
712 | ||
713 | M_MMAP_THRESHOLD is the request size threshold for using mmap() | |
714 | to service a request. Requests of at least this size that cannot | |
715 | be allocated using already-existing space will be serviced via mmap. | |
716 | (If enough normal freed space already exists it is used instead.) | |
717 | ||
718 | Using mmap segregates relatively large chunks of memory so that | |
719 | they can be individually obtained and released from the host | |
720 | system. A request serviced through mmap is never reused by any | |
721 | other request (at least not directly; the system may just so | |
722 | happen to remap successive requests to the same locations). | |
723 | ||
724 | Segregating space in this way has the benefit that mmapped space | |
725 | can ALWAYS be individually released back to the system, which | |
726 | helps keep the system level memory demands of a long-lived | |
727 | program low. Mapped memory can never become `locked' between | |
728 | other chunks, as can happen with normally allocated chunks, which | |
729 | menas that even trimming via malloc_trim would not release them. | |
730 | ||
731 | However, it has the disadvantages that: | |
732 | ||
733 | 1. The space cannot be reclaimed, consolidated, and then | |
734 | used to service later requests, as happens with normal chunks. | |
735 | 2. It can lead to more wastage because of mmap page alignment | |
736 | requirements | |
737 | 3. It causes malloc performance to be more dependent on host | |
738 | system memory management support routines which may vary in | |
739 | implementation quality and may impose arbitrary | |
740 | limitations. Generally, servicing a request via normal | |
741 | malloc steps is faster than going through a system's mmap. | |
742 | ||
743 | All together, these considerations should lead you to use mmap | |
744 | only for relatively large requests. | |
745 | ||
746 | ||
747 | */ | |
748 | ||
749 | ||
750 | ||
751 | #ifndef DEFAULT_MMAP_MAX | |
752 | #if HAVE_MMAP | |
753 | #define DEFAULT_MMAP_MAX (1024) | |
754 | #else | |
755 | #define DEFAULT_MMAP_MAX (0) | |
756 | #endif | |
757 | #endif | |
758 | ||
759 | /* | |
760 | M_MMAP_MAX is the maximum number of requests to simultaneously | |
761 | service using mmap. This parameter exists because: | |
762 | ||
763 | 1. Some systems have a limited number of internal tables for | |
764 | use by mmap. | |
765 | 2. In most systems, overreliance on mmap can degrade overall | |
766 | performance. | |
767 | 3. If a program allocates many large regions, it is probably | |
768 | better off using normal sbrk-based allocation routines that | |
769 | can reclaim and reallocate normal heap memory. Using a | |
770 | small value allows transition into this mode after the | |
771 | first few allocations. | |
772 | ||
773 | Setting to 0 disables all use of mmap. If HAVE_MMAP is not set, | |
774 | the default value is 0, and attempts to set it to non-zero values | |
775 | in mallopt will fail. | |
776 | */ | |
777 | ||
778 | ||
779 | ||
10dc2a90 UD |
780 | #ifndef DEFAULT_CHECK_ACTION |
781 | #define DEFAULT_CHECK_ACTION 1 | |
782 | #endif | |
783 | ||
784 | /* What to do if the standard debugging hooks are in place and a | |
785 | corrupt pointer is detected: do nothing (0), print an error message | |
786 | (1), or call abort() (2). */ | |
787 | ||
788 | ||
789 | ||
f65fd747 UD |
790 | #define HEAP_MIN_SIZE (32*1024) |
791 | #define HEAP_MAX_SIZE (1024*1024) /* must be a power of two */ | |
792 | ||
793 | /* HEAP_MIN_SIZE and HEAP_MAX_SIZE limit the size of mmap()ed heaps | |
794 | that are dynamically created for multi-threaded programs. The | |
795 | maximum size must be a power of two, for fast determination of | |
796 | which heap belongs to a chunk. It should be much larger than | |
797 | the mmap threshold, so that requests with a size just below that | |
798 | threshold can be fulfilled without creating too many heaps. | |
799 | */ | |
800 | ||
801 | ||
802 | ||
803 | #ifndef THREAD_STATS | |
804 | #define THREAD_STATS 0 | |
805 | #endif | |
806 | ||
807 | /* If THREAD_STATS is non-zero, some statistics on mutex locking are | |
808 | computed. */ | |
809 | ||
810 | ||
811 | /* | |
812 | ||
813 | Special defines for the Linux/GNU C library. | |
814 | ||
815 | */ | |
816 | ||
817 | ||
818 | #ifdef _LIBC | |
819 | ||
820 | #if __STD_C | |
821 | ||
822 | Void_t * __default_morecore (ptrdiff_t); | |
1228ed5c | 823 | Void_t *(*__morecore)(ptrdiff_t) = __default_morecore; |
f65fd747 UD |
824 | |
825 | #else | |
826 | ||
827 | Void_t * __default_morecore (); | |
1228ed5c | 828 | Void_t *(*__morecore)() = __default_morecore; |
f65fd747 UD |
829 | |
830 | #endif | |
831 | ||
832 | #define MORECORE (*__morecore) | |
833 | #define MORECORE_FAILURE 0 | |
834 | #define MORECORE_CLEARS 1 | |
10dc2a90 UD |
835 | #define mmap __mmap |
836 | #define munmap __munmap | |
837 | #define mremap __mremap | |
4cca6b86 | 838 | #define mprotect __mprotect |
10dc2a90 UD |
839 | #undef malloc_getpagesize |
840 | #define malloc_getpagesize __getpagesize() | |
f65fd747 UD |
841 | |
842 | #else /* _LIBC */ | |
843 | ||
844 | #if __STD_C | |
845 | extern Void_t* sbrk(ptrdiff_t); | |
846 | #else | |
847 | extern Void_t* sbrk(); | |
848 | #endif | |
849 | ||
850 | #ifndef MORECORE | |
851 | #define MORECORE sbrk | |
852 | #endif | |
853 | ||
854 | #ifndef MORECORE_FAILURE | |
855 | #define MORECORE_FAILURE -1 | |
856 | #endif | |
857 | ||
858 | #ifndef MORECORE_CLEARS | |
859 | #define MORECORE_CLEARS 1 | |
860 | #endif | |
861 | ||
862 | #endif /* _LIBC */ | |
863 | ||
10dc2a90 | 864 | #ifdef _LIBC |
f65fd747 UD |
865 | |
866 | #define cALLOc __libc_calloc | |
867 | #define fREe __libc_free | |
868 | #define mALLOc __libc_malloc | |
869 | #define mEMALIGn __libc_memalign | |
870 | #define rEALLOc __libc_realloc | |
871 | #define vALLOc __libc_valloc | |
872 | #define pvALLOc __libc_pvalloc | |
873 | #define mALLINFo __libc_mallinfo | |
874 | #define mALLOPt __libc_mallopt | |
7e3be507 UD |
875 | #define mALLOC_STATs __malloc_stats |
876 | #define mALLOC_USABLE_SIZe __malloc_usable_size | |
877 | #define mALLOC_TRIm __malloc_trim | |
2f6d1f1b UD |
878 | #define mALLOC_GET_STATe __malloc_get_state |
879 | #define mALLOC_SET_STATe __malloc_set_state | |
f65fd747 | 880 | |
f65fd747 UD |
881 | #else |
882 | ||
883 | #define cALLOc calloc | |
884 | #define fREe free | |
885 | #define mALLOc malloc | |
886 | #define mEMALIGn memalign | |
887 | #define rEALLOc realloc | |
888 | #define vALLOc valloc | |
889 | #define pvALLOc pvalloc | |
890 | #define mALLINFo mallinfo | |
891 | #define mALLOPt mallopt | |
7e3be507 UD |
892 | #define mALLOC_STATs malloc_stats |
893 | #define mALLOC_USABLE_SIZe malloc_usable_size | |
894 | #define mALLOC_TRIm malloc_trim | |
2f6d1f1b UD |
895 | #define mALLOC_GET_STATe malloc_get_state |
896 | #define mALLOC_SET_STATe malloc_set_state | |
f65fd747 UD |
897 | |
898 | #endif | |
899 | ||
900 | /* Public routines */ | |
901 | ||
902 | #if __STD_C | |
903 | ||
904 | #ifndef _LIBC | |
905 | void ptmalloc_init(void); | |
906 | #endif | |
907 | Void_t* mALLOc(size_t); | |
908 | void fREe(Void_t*); | |
909 | Void_t* rEALLOc(Void_t*, size_t); | |
910 | Void_t* mEMALIGn(size_t, size_t); | |
911 | Void_t* vALLOc(size_t); | |
912 | Void_t* pvALLOc(size_t); | |
913 | Void_t* cALLOc(size_t, size_t); | |
914 | void cfree(Void_t*); | |
7e3be507 UD |
915 | int mALLOC_TRIm(size_t); |
916 | size_t mALLOC_USABLE_SIZe(Void_t*); | |
917 | void mALLOC_STATs(void); | |
f65fd747 UD |
918 | int mALLOPt(int, int); |
919 | struct mallinfo mALLINFo(void); | |
2f6d1f1b UD |
920 | Void_t* mALLOC_GET_STATe(void); |
921 | int mALLOC_SET_STATe(Void_t*); | |
922 | ||
923 | #else /* !__STD_C */ | |
924 | ||
f65fd747 UD |
925 | #ifndef _LIBC |
926 | void ptmalloc_init(); | |
927 | #endif | |
928 | Void_t* mALLOc(); | |
929 | void fREe(); | |
930 | Void_t* rEALLOc(); | |
931 | Void_t* mEMALIGn(); | |
932 | Void_t* vALLOc(); | |
933 | Void_t* pvALLOc(); | |
934 | Void_t* cALLOc(); | |
935 | void cfree(); | |
7e3be507 UD |
936 | int mALLOC_TRIm(); |
937 | size_t mALLOC_USABLE_SIZe(); | |
938 | void mALLOC_STATs(); | |
f65fd747 UD |
939 | int mALLOPt(); |
940 | struct mallinfo mALLINFo(); | |
2f6d1f1b UD |
941 | Void_t* mALLOC_GET_STATe(); |
942 | int mALLOC_SET_STATe(); | |
943 | ||
944 | #endif /* __STD_C */ | |
f65fd747 UD |
945 | |
946 | ||
947 | #ifdef __cplusplus | |
948 | }; /* end of extern "C" */ | |
949 | #endif | |
950 | ||
951 | #if !defined(NO_THREADS) && !HAVE_MMAP | |
952 | "Can't have threads support without mmap" | |
953 | #endif | |
954 | ||
955 | ||
956 | /* | |
957 | Type declarations | |
958 | */ | |
959 | ||
960 | ||
961 | struct malloc_chunk | |
962 | { | |
963 | INTERNAL_SIZE_T prev_size; /* Size of previous chunk (if free). */ | |
964 | INTERNAL_SIZE_T size; /* Size in bytes, including overhead. */ | |
965 | struct malloc_chunk* fd; /* double links -- used only if free. */ | |
966 | struct malloc_chunk* bk; | |
967 | }; | |
968 | ||
969 | typedef struct malloc_chunk* mchunkptr; | |
970 | ||
971 | /* | |
972 | ||
973 | malloc_chunk details: | |
974 | ||
975 | (The following includes lightly edited explanations by Colin Plumb.) | |
976 | ||
977 | Chunks of memory are maintained using a `boundary tag' method as | |
978 | described in e.g., Knuth or Standish. (See the paper by Paul | |
979 | Wilson ftp://ftp.cs.utexas.edu/pub/garbage/allocsrv.ps for a | |
980 | survey of such techniques.) Sizes of free chunks are stored both | |
981 | in the front of each chunk and at the end. This makes | |
982 | consolidating fragmented chunks into bigger chunks very fast. The | |
983 | size fields also hold bits representing whether chunks are free or | |
984 | in use. | |
985 | ||
986 | An allocated chunk looks like this: | |
987 | ||
988 | ||
989 | chunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
990 | | Size of previous chunk, if allocated | | | |
991 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
992 | | Size of chunk, in bytes |P| | |
993 | mem-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
994 | | User data starts here... . | |
995 | . . | |
996 | . (malloc_usable_space() bytes) . | |
997 | . | | |
998 | nextchunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
999 | | Size of chunk | | |
1000 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
1001 | ||
1002 | ||
1003 | Where "chunk" is the front of the chunk for the purpose of most of | |
1004 | the malloc code, but "mem" is the pointer that is returned to the | |
1005 | user. "Nextchunk" is the beginning of the next contiguous chunk. | |
1006 | ||
6d52618b | 1007 | Chunks always begin on even word boundaries, so the mem portion |
f65fd747 UD |
1008 | (which is returned to the user) is also on an even word boundary, and |
1009 | thus double-word aligned. | |
1010 | ||
1011 | Free chunks are stored in circular doubly-linked lists, and look like this: | |
1012 | ||
1013 | chunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
1014 | | Size of previous chunk | | |
1015 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
1016 | `head:' | Size of chunk, in bytes |P| | |
1017 | mem-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
1018 | | Forward pointer to next chunk in list | | |
1019 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
1020 | | Back pointer to previous chunk in list | | |
1021 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
1022 | | Unused space (may be 0 bytes long) . | |
1023 | . . | |
1024 | . | | |
1025 | nextchunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
1026 | `foot:' | Size of chunk, in bytes | | |
1027 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
1028 | ||
1029 | The P (PREV_INUSE) bit, stored in the unused low-order bit of the | |
1030 | chunk size (which is always a multiple of two words), is an in-use | |
1031 | bit for the *previous* chunk. If that bit is *clear*, then the | |
1032 | word before the current chunk size contains the previous chunk | |
1033 | size, and can be used to find the front of the previous chunk. | |
1034 | (The very first chunk allocated always has this bit set, | |
1035 | preventing access to non-existent (or non-owned) memory.) | |
1036 | ||
1037 | Note that the `foot' of the current chunk is actually represented | |
1038 | as the prev_size of the NEXT chunk. (This makes it easier to | |
1039 | deal with alignments etc). | |
1040 | ||
1041 | The two exceptions to all this are | |
1042 | ||
1043 | 1. The special chunk `top', which doesn't bother using the | |
1044 | trailing size field since there is no | |
1045 | next contiguous chunk that would have to index off it. (After | |
1046 | initialization, `top' is forced to always exist. If it would | |
1047 | become less than MINSIZE bytes long, it is replenished via | |
1048 | malloc_extend_top.) | |
1049 | ||
1050 | 2. Chunks allocated via mmap, which have the second-lowest-order | |
1051 | bit (IS_MMAPPED) set in their size fields. Because they are | |
1052 | never merged or traversed from any other chunk, they have no | |
1053 | foot size or inuse information. | |
1054 | ||
1055 | Available chunks are kept in any of several places (all declared below): | |
1056 | ||
1057 | * `av': An array of chunks serving as bin headers for consolidated | |
1058 | chunks. Each bin is doubly linked. The bins are approximately | |
1059 | proportionally (log) spaced. There are a lot of these bins | |
1060 | (128). This may look excessive, but works very well in | |
1061 | practice. All procedures maintain the invariant that no | |
1062 | consolidated chunk physically borders another one. Chunks in | |
1063 | bins are kept in size order, with ties going to the | |
1064 | approximately least recently used chunk. | |
1065 | ||
1066 | The chunks in each bin are maintained in decreasing sorted order by | |
1067 | size. This is irrelevant for the small bins, which all contain | |
1068 | the same-sized chunks, but facilitates best-fit allocation for | |
1069 | larger chunks. (These lists are just sequential. Keeping them in | |
1070 | order almost never requires enough traversal to warrant using | |
1071 | fancier ordered data structures.) Chunks of the same size are | |
1072 | linked with the most recently freed at the front, and allocations | |
1073 | are taken from the back. This results in LRU or FIFO allocation | |
1074 | order, which tends to give each chunk an equal opportunity to be | |
1075 | consolidated with adjacent freed chunks, resulting in larger free | |
1076 | chunks and less fragmentation. | |
1077 | ||
1078 | * `top': The top-most available chunk (i.e., the one bordering the | |
1079 | end of available memory) is treated specially. It is never | |
1080 | included in any bin, is used only if no other chunk is | |
1081 | available, and is released back to the system if it is very | |
1082 | large (see M_TRIM_THRESHOLD). | |
1083 | ||
1084 | * `last_remainder': A bin holding only the remainder of the | |
1085 | most recently split (non-top) chunk. This bin is checked | |
1086 | before other non-fitting chunks, so as to provide better | |
1087 | locality for runs of sequentially allocated chunks. | |
1088 | ||
1089 | * Implicitly, through the host system's memory mapping tables. | |
1090 | If supported, requests greater than a threshold are usually | |
1091 | serviced via calls to mmap, and then later released via munmap. | |
1092 | ||
1093 | */ | |
1094 | ||
1095 | /* | |
1096 | Bins | |
1097 | ||
1098 | The bins are an array of pairs of pointers serving as the | |
1099 | heads of (initially empty) doubly-linked lists of chunks, laid out | |
1100 | in a way so that each pair can be treated as if it were in a | |
1101 | malloc_chunk. (This way, the fd/bk offsets for linking bin heads | |
1102 | and chunks are the same). | |
1103 | ||
1104 | Bins for sizes < 512 bytes contain chunks of all the same size, spaced | |
1105 | 8 bytes apart. Larger bins are approximately logarithmically | |
1106 | spaced. (See the table below.) | |
1107 | ||
1108 | Bin layout: | |
1109 | ||
1110 | 64 bins of size 8 | |
1111 | 32 bins of size 64 | |
1112 | 16 bins of size 512 | |
1113 | 8 bins of size 4096 | |
1114 | 4 bins of size 32768 | |
1115 | 2 bins of size 262144 | |
1116 | 1 bin of size what's left | |
1117 | ||
1118 | There is actually a little bit of slop in the numbers in bin_index | |
1119 | for the sake of speed. This makes no difference elsewhere. | |
1120 | ||
1121 | The special chunks `top' and `last_remainder' get their own bins, | |
1122 | (this is implemented via yet more trickery with the av array), | |
1123 | although `top' is never properly linked to its bin since it is | |
1124 | always handled specially. | |
1125 | ||
1126 | */ | |
1127 | ||
1128 | #define NAV 128 /* number of bins */ | |
1129 | ||
1130 | typedef struct malloc_chunk* mbinptr; | |
1131 | ||
1132 | /* An arena is a configuration of malloc_chunks together with an array | |
1133 | of bins. With multiple threads, it must be locked via a mutex | |
1134 | before changing its data structures. One or more `heaps' are | |
1135 | associated with each arena, except for the main_arena, which is | |
1136 | associated only with the `main heap', i.e. the conventional free | |
1137 | store obtained with calls to MORECORE() (usually sbrk). The `av' | |
1138 | array is never mentioned directly in the code, but instead used via | |
1139 | bin access macros. */ | |
1140 | ||
1141 | typedef struct _arena { | |
1142 | mbinptr av[2*NAV + 2]; | |
1143 | struct _arena *next; | |
8a4b65b4 UD |
1144 | size_t size; |
1145 | #if THREAD_STATS | |
1146 | long stat_lock_direct, stat_lock_loop, stat_lock_wait; | |
1147 | #endif | |
f65fd747 UD |
1148 | mutex_t mutex; |
1149 | } arena; | |
1150 | ||
1151 | ||
6d52618b | 1152 | /* A heap is a single contiguous memory region holding (coalesceable) |
f65fd747 UD |
1153 | malloc_chunks. It is allocated with mmap() and always starts at an |
1154 | address aligned to HEAP_MAX_SIZE. Not used unless compiling for | |
1155 | multiple threads. */ | |
1156 | ||
1157 | typedef struct _heap_info { | |
8a4b65b4 UD |
1158 | arena *ar_ptr; /* Arena for this heap. */ |
1159 | struct _heap_info *prev; /* Previous heap. */ | |
1160 | size_t size; /* Current size in bytes. */ | |
1161 | size_t pad; /* Make sure the following data is properly aligned. */ | |
f65fd747 UD |
1162 | } heap_info; |
1163 | ||
1164 | ||
1165 | /* | |
1166 | Static functions (forward declarations) | |
1167 | */ | |
1168 | ||
1169 | #if __STD_C | |
10dc2a90 | 1170 | |
dfd2257a UD |
1171 | static void chunk_free(arena *ar_ptr, mchunkptr p) internal_function; |
1172 | static mchunkptr chunk_alloc(arena *ar_ptr, INTERNAL_SIZE_T size) | |
1173 | internal_function; | |
10dc2a90 | 1174 | static mchunkptr chunk_realloc(arena *ar_ptr, mchunkptr oldp, |
dfd2257a UD |
1175 | INTERNAL_SIZE_T oldsize, INTERNAL_SIZE_T nb) |
1176 | internal_function; | |
10dc2a90 | 1177 | static mchunkptr chunk_align(arena *ar_ptr, INTERNAL_SIZE_T nb, |
dfd2257a UD |
1178 | size_t alignment) internal_function; |
1179 | static int main_trim(size_t pad) internal_function; | |
8a4b65b4 | 1180 | #ifndef NO_THREADS |
dfd2257a | 1181 | static int heap_trim(heap_info *heap, size_t pad) internal_function; |
8a4b65b4 | 1182 | #endif |
dfd2257a | 1183 | #if defined _LIBC || defined MALLOC_HOOKS |
a2b08ee5 UD |
1184 | static Void_t* malloc_check(size_t sz, const Void_t *caller); |
1185 | static void free_check(Void_t* mem, const Void_t *caller); | |
1186 | static Void_t* realloc_check(Void_t* oldmem, size_t bytes, | |
1187 | const Void_t *caller); | |
1188 | static Void_t* memalign_check(size_t alignment, size_t bytes, | |
1189 | const Void_t *caller); | |
1190 | static Void_t* malloc_starter(size_t sz, const Void_t *caller); | |
1191 | static void free_starter(Void_t* mem, const Void_t *caller); | |
1192 | static Void_t* malloc_atfork(size_t sz, const Void_t *caller); | |
1193 | static void free_atfork(Void_t* mem, const Void_t *caller); | |
a2b08ee5 | 1194 | #endif |
10dc2a90 | 1195 | |
f65fd747 | 1196 | #else |
10dc2a90 | 1197 | |
f65fd747 UD |
1198 | static void chunk_free(); |
1199 | static mchunkptr chunk_alloc(); | |
10dc2a90 UD |
1200 | static mchunkptr chunk_realloc(); |
1201 | static mchunkptr chunk_align(); | |
8a4b65b4 UD |
1202 | static int main_trim(); |
1203 | #ifndef NO_THREADS | |
1204 | static int heap_trim(); | |
1205 | #endif | |
dfd2257a | 1206 | #if defined _LIBC || defined MALLOC_HOOKS |
10dc2a90 UD |
1207 | static Void_t* malloc_check(); |
1208 | static void free_check(); | |
1209 | static Void_t* realloc_check(); | |
1210 | static Void_t* memalign_check(); | |
7e3be507 UD |
1211 | static Void_t* malloc_starter(); |
1212 | static void free_starter(); | |
ca34d7a7 UD |
1213 | static Void_t* malloc_atfork(); |
1214 | static void free_atfork(); | |
10dc2a90 UD |
1215 | #endif |
1216 | ||
f65fd747 UD |
1217 | #endif |
1218 | ||
dfd2257a UD |
1219 | /* On some platforms we can compile internal, not exported functions better. |
1220 | Let the environment provide a macro and define it to be empty if it | |
1221 | is not available. */ | |
1222 | #ifndef internal_function | |
1223 | # define internal_function | |
1224 | #endif | |
1225 | ||
f65fd747 UD |
1226 | \f |
1227 | ||
1228 | /* sizes, alignments */ | |
1229 | ||
1230 | #define SIZE_SZ (sizeof(INTERNAL_SIZE_T)) | |
1231 | #define MALLOC_ALIGNMENT (SIZE_SZ + SIZE_SZ) | |
1232 | #define MALLOC_ALIGN_MASK (MALLOC_ALIGNMENT - 1) | |
1233 | #define MINSIZE (sizeof(struct malloc_chunk)) | |
1234 | ||
1235 | /* conversion from malloc headers to user pointers, and back */ | |
1236 | ||
1237 | #define chunk2mem(p) ((Void_t*)((char*)(p) + 2*SIZE_SZ)) | |
1238 | #define mem2chunk(mem) ((mchunkptr)((char*)(mem) - 2*SIZE_SZ)) | |
1239 | ||
1240 | /* pad request bytes into a usable size */ | |
1241 | ||
1242 | #define request2size(req) \ | |
1243 | (((long)((req) + (SIZE_SZ + MALLOC_ALIGN_MASK)) < \ | |
1244 | (long)(MINSIZE + MALLOC_ALIGN_MASK)) ? MINSIZE : \ | |
1245 | (((req) + (SIZE_SZ + MALLOC_ALIGN_MASK)) & ~(MALLOC_ALIGN_MASK))) | |
1246 | ||
1247 | /* Check if m has acceptable alignment */ | |
1248 | ||
1249 | #define aligned_OK(m) (((unsigned long)((m)) & (MALLOC_ALIGN_MASK)) == 0) | |
1250 | ||
1251 | ||
1252 | \f | |
1253 | ||
1254 | /* | |
1255 | Physical chunk operations | |
1256 | */ | |
1257 | ||
1258 | ||
1259 | /* size field is or'ed with PREV_INUSE when previous adjacent chunk in use */ | |
1260 | ||
1261 | #define PREV_INUSE 0x1 | |
1262 | ||
1263 | /* size field is or'ed with IS_MMAPPED if the chunk was obtained with mmap() */ | |
1264 | ||
1265 | #define IS_MMAPPED 0x2 | |
1266 | ||
1267 | /* Bits to mask off when extracting size */ | |
1268 | ||
1269 | #define SIZE_BITS (PREV_INUSE|IS_MMAPPED) | |
1270 | ||
1271 | ||
1272 | /* Ptr to next physical malloc_chunk. */ | |
1273 | ||
1274 | #define next_chunk(p) ((mchunkptr)( ((char*)(p)) + ((p)->size & ~PREV_INUSE) )) | |
1275 | ||
1276 | /* Ptr to previous physical malloc_chunk */ | |
1277 | ||
1278 | #define prev_chunk(p) ((mchunkptr)( ((char*)(p)) - ((p)->prev_size) )) | |
1279 | ||
1280 | ||
1281 | /* Treat space at ptr + offset as a chunk */ | |
1282 | ||
1283 | #define chunk_at_offset(p, s) ((mchunkptr)(((char*)(p)) + (s))) | |
1284 | ||
1285 | ||
1286 | \f | |
1287 | ||
1288 | /* | |
1289 | Dealing with use bits | |
1290 | */ | |
1291 | ||
1292 | /* extract p's inuse bit */ | |
1293 | ||
1294 | #define inuse(p) \ | |
1295 | ((((mchunkptr)(((char*)(p))+((p)->size & ~PREV_INUSE)))->size) & PREV_INUSE) | |
1296 | ||
1297 | /* extract inuse bit of previous chunk */ | |
1298 | ||
1299 | #define prev_inuse(p) ((p)->size & PREV_INUSE) | |
1300 | ||
1301 | /* check for mmap()'ed chunk */ | |
1302 | ||
1303 | #define chunk_is_mmapped(p) ((p)->size & IS_MMAPPED) | |
1304 | ||
1305 | /* set/clear chunk as in use without otherwise disturbing */ | |
1306 | ||
1307 | #define set_inuse(p) \ | |
1308 | ((mchunkptr)(((char*)(p)) + ((p)->size & ~PREV_INUSE)))->size |= PREV_INUSE | |
1309 | ||
1310 | #define clear_inuse(p) \ | |
1311 | ((mchunkptr)(((char*)(p)) + ((p)->size & ~PREV_INUSE)))->size &= ~(PREV_INUSE) | |
1312 | ||
1313 | /* check/set/clear inuse bits in known places */ | |
1314 | ||
1315 | #define inuse_bit_at_offset(p, s)\ | |
1316 | (((mchunkptr)(((char*)(p)) + (s)))->size & PREV_INUSE) | |
1317 | ||
1318 | #define set_inuse_bit_at_offset(p, s)\ | |
1319 | (((mchunkptr)(((char*)(p)) + (s)))->size |= PREV_INUSE) | |
1320 | ||
1321 | #define clear_inuse_bit_at_offset(p, s)\ | |
1322 | (((mchunkptr)(((char*)(p)) + (s)))->size &= ~(PREV_INUSE)) | |
1323 | ||
1324 | ||
1325 | \f | |
1326 | ||
1327 | /* | |
1328 | Dealing with size fields | |
1329 | */ | |
1330 | ||
1331 | /* Get size, ignoring use bits */ | |
1332 | ||
1333 | #define chunksize(p) ((p)->size & ~(SIZE_BITS)) | |
1334 | ||
1335 | /* Set size at head, without disturbing its use bit */ | |
1336 | ||
1337 | #define set_head_size(p, s) ((p)->size = (((p)->size & PREV_INUSE) | (s))) | |
1338 | ||
1339 | /* Set size/use ignoring previous bits in header */ | |
1340 | ||
1341 | #define set_head(p, s) ((p)->size = (s)) | |
1342 | ||
1343 | /* Set size at footer (only when chunk is not in use) */ | |
1344 | ||
1345 | #define set_foot(p, s) (((mchunkptr)((char*)(p) + (s)))->prev_size = (s)) | |
1346 | ||
1347 | ||
1348 | \f | |
1349 | ||
1350 | ||
1351 | /* access macros */ | |
1352 | ||
1353 | #define bin_at(a, i) ((mbinptr)((char*)&(((a)->av)[2*(i) + 2]) - 2*SIZE_SZ)) | |
1354 | #define init_bin(a, i) ((a)->av[2*i+2] = (a)->av[2*i+3] = bin_at((a), i)) | |
1355 | #define next_bin(b) ((mbinptr)((char*)(b) + 2 * sizeof(mbinptr))) | |
1356 | #define prev_bin(b) ((mbinptr)((char*)(b) - 2 * sizeof(mbinptr))) | |
1357 | ||
1358 | /* | |
1359 | The first 2 bins are never indexed. The corresponding av cells are instead | |
1360 | used for bookkeeping. This is not to save space, but to simplify | |
1361 | indexing, maintain locality, and avoid some initialization tests. | |
1362 | */ | |
1363 | ||
1364 | #define binblocks(a) (bin_at(a,0)->size)/* bitvector of nonempty blocks */ | |
1365 | #define top(a) (bin_at(a,0)->fd) /* The topmost chunk */ | |
1366 | #define last_remainder(a) (bin_at(a,1)) /* remainder from last split */ | |
1367 | ||
1368 | /* | |
1369 | Because top initially points to its own bin with initial | |
1370 | zero size, thus forcing extension on the first malloc request, | |
1371 | we avoid having any special code in malloc to check whether | |
1372 | it even exists yet. But we still need to in malloc_extend_top. | |
1373 | */ | |
1374 | ||
1375 | #define initial_top(a) ((mchunkptr)bin_at(a, 0)) | |
1376 | ||
1377 | \f | |
1378 | ||
1379 | /* field-extraction macros */ | |
1380 | ||
1381 | #define first(b) ((b)->fd) | |
1382 | #define last(b) ((b)->bk) | |
1383 | ||
1384 | /* | |
1385 | Indexing into bins | |
1386 | */ | |
1387 | ||
dfd2257a UD |
1388 | #define bin_index(sz) \ |
1389 | (((((unsigned long)(sz)) >> 9) == 0) ? (((unsigned long)(sz)) >> 3):\ | |
1390 | ((((unsigned long)(sz)) >> 9) <= 4) ? 56 + (((unsigned long)(sz)) >> 6):\ | |
1391 | ((((unsigned long)(sz)) >> 9) <= 20) ? 91 + (((unsigned long)(sz)) >> 9):\ | |
1392 | ((((unsigned long)(sz)) >> 9) <= 84) ? 110 + (((unsigned long)(sz)) >> 12):\ | |
1393 | ((((unsigned long)(sz)) >> 9) <= 340) ? 119 + (((unsigned long)(sz)) >> 15):\ | |
1394 | ((((unsigned long)(sz)) >> 9) <= 1364) ? 124 + (((unsigned long)(sz)) >> 18):\ | |
f65fd747 UD |
1395 | 126) |
1396 | /* | |
1397 | bins for chunks < 512 are all spaced 8 bytes apart, and hold | |
1398 | identically sized chunks. This is exploited in malloc. | |
1399 | */ | |
1400 | ||
1401 | #define MAX_SMALLBIN 63 | |
1402 | #define MAX_SMALLBIN_SIZE 512 | |
1403 | #define SMALLBIN_WIDTH 8 | |
1404 | ||
1405 | #define smallbin_index(sz) (((unsigned long)(sz)) >> 3) | |
1406 | ||
1407 | /* | |
1408 | Requests are `small' if both the corresponding and the next bin are small | |
1409 | */ | |
1410 | ||
1411 | #define is_small_request(nb) ((nb) < MAX_SMALLBIN_SIZE - SMALLBIN_WIDTH) | |
1412 | ||
1413 | \f | |
1414 | ||
1415 | /* | |
1416 | To help compensate for the large number of bins, a one-level index | |
1417 | structure is used for bin-by-bin searching. `binblocks' is a | |
1418 | one-word bitvector recording whether groups of BINBLOCKWIDTH bins | |
1419 | have any (possibly) non-empty bins, so they can be skipped over | |
1420 | all at once during during traversals. The bits are NOT always | |
1421 | cleared as soon as all bins in a block are empty, but instead only | |
1422 | when all are noticed to be empty during traversal in malloc. | |
1423 | */ | |
1424 | ||
1425 | #define BINBLOCKWIDTH 4 /* bins per block */ | |
1426 | ||
1427 | /* bin<->block macros */ | |
1428 | ||
1429 | #define idx2binblock(ix) ((unsigned)1 << ((ix) / BINBLOCKWIDTH)) | |
1430 | #define mark_binblock(a, ii) (binblocks(a) |= idx2binblock(ii)) | |
1431 | #define clear_binblock(a, ii) (binblocks(a) &= ~(idx2binblock(ii))) | |
1432 | ||
1433 | ||
1434 | \f | |
1435 | ||
1436 | /* Static bookkeeping data */ | |
1437 | ||
1438 | /* Helper macro to initialize bins */ | |
1439 | #define IAV(i) bin_at(&main_arena, i), bin_at(&main_arena, i) | |
1440 | ||
1441 | static arena main_arena = { | |
1442 | { | |
1443 | 0, 0, | |
1444 | IAV(0), IAV(1), IAV(2), IAV(3), IAV(4), IAV(5), IAV(6), IAV(7), | |
1445 | IAV(8), IAV(9), IAV(10), IAV(11), IAV(12), IAV(13), IAV(14), IAV(15), | |
1446 | IAV(16), IAV(17), IAV(18), IAV(19), IAV(20), IAV(21), IAV(22), IAV(23), | |
1447 | IAV(24), IAV(25), IAV(26), IAV(27), IAV(28), IAV(29), IAV(30), IAV(31), | |
1448 | IAV(32), IAV(33), IAV(34), IAV(35), IAV(36), IAV(37), IAV(38), IAV(39), | |
1449 | IAV(40), IAV(41), IAV(42), IAV(43), IAV(44), IAV(45), IAV(46), IAV(47), | |
1450 | IAV(48), IAV(49), IAV(50), IAV(51), IAV(52), IAV(53), IAV(54), IAV(55), | |
1451 | IAV(56), IAV(57), IAV(58), IAV(59), IAV(60), IAV(61), IAV(62), IAV(63), | |
1452 | IAV(64), IAV(65), IAV(66), IAV(67), IAV(68), IAV(69), IAV(70), IAV(71), | |
1453 | IAV(72), IAV(73), IAV(74), IAV(75), IAV(76), IAV(77), IAV(78), IAV(79), | |
1454 | IAV(80), IAV(81), IAV(82), IAV(83), IAV(84), IAV(85), IAV(86), IAV(87), | |
1455 | IAV(88), IAV(89), IAV(90), IAV(91), IAV(92), IAV(93), IAV(94), IAV(95), | |
1456 | IAV(96), IAV(97), IAV(98), IAV(99), IAV(100), IAV(101), IAV(102), IAV(103), | |
1457 | IAV(104), IAV(105), IAV(106), IAV(107), IAV(108), IAV(109), IAV(110), IAV(111), | |
1458 | IAV(112), IAV(113), IAV(114), IAV(115), IAV(116), IAV(117), IAV(118), IAV(119), | |
1459 | IAV(120), IAV(121), IAV(122), IAV(123), IAV(124), IAV(125), IAV(126), IAV(127) | |
1460 | }, | |
7e3be507 | 1461 | &main_arena, /* next */ |
8a4b65b4 UD |
1462 | 0, /* size */ |
1463 | #if THREAD_STATS | |
1464 | 0, 0, 0, /* stat_lock_direct, stat_lock_loop, stat_lock_wait */ | |
1465 | #endif | |
f65fd747 UD |
1466 | MUTEX_INITIALIZER /* mutex */ |
1467 | }; | |
1468 | ||
1469 | #undef IAV | |
1470 | ||
1471 | /* Thread specific data */ | |
1472 | ||
8a4b65b4 | 1473 | #ifndef NO_THREADS |
f65fd747 UD |
1474 | static tsd_key_t arena_key; |
1475 | static mutex_t list_lock = MUTEX_INITIALIZER; | |
8a4b65b4 | 1476 | #endif |
f65fd747 UD |
1477 | |
1478 | #if THREAD_STATS | |
f65fd747 | 1479 | static int stat_n_heaps = 0; |
f65fd747 UD |
1480 | #define THREAD_STAT(x) x |
1481 | #else | |
1482 | #define THREAD_STAT(x) do ; while(0) | |
1483 | #endif | |
1484 | ||
1485 | /* variables holding tunable values */ | |
1486 | ||
1487 | static unsigned long trim_threshold = DEFAULT_TRIM_THRESHOLD; | |
1488 | static unsigned long top_pad = DEFAULT_TOP_PAD; | |
1489 | static unsigned int n_mmaps_max = DEFAULT_MMAP_MAX; | |
1490 | static unsigned long mmap_threshold = DEFAULT_MMAP_THRESHOLD; | |
10dc2a90 | 1491 | static int check_action = DEFAULT_CHECK_ACTION; |
f65fd747 UD |
1492 | |
1493 | /* The first value returned from sbrk */ | |
1494 | static char* sbrk_base = (char*)(-1); | |
1495 | ||
1496 | /* The maximum memory obtained from system via sbrk */ | |
1497 | static unsigned long max_sbrked_mem = 0; | |
1498 | ||
8a4b65b4 UD |
1499 | /* The maximum via either sbrk or mmap (too difficult to track with threads) */ |
1500 | #ifdef NO_THREADS | |
f65fd747 | 1501 | static unsigned long max_total_mem = 0; |
8a4b65b4 | 1502 | #endif |
f65fd747 UD |
1503 | |
1504 | /* The total memory obtained from system via sbrk */ | |
8a4b65b4 | 1505 | #define sbrked_mem (main_arena.size) |
f65fd747 UD |
1506 | |
1507 | /* Tracking mmaps */ | |
1508 | ||
1509 | static unsigned int n_mmaps = 0; | |
1510 | static unsigned int max_n_mmaps = 0; | |
1511 | static unsigned long mmapped_mem = 0; | |
1512 | static unsigned long max_mmapped_mem = 0; | |
1513 | ||
1514 | ||
1515 | \f | |
831372e7 UD |
1516 | #ifndef _LIBC |
1517 | #define weak_variable | |
1518 | #else | |
1519 | /* In GNU libc we want the hook variables to be weak definitions to | |
1520 | avoid a problem with Emacs. */ | |
1521 | #define weak_variable weak_function | |
1522 | #endif | |
7e3be507 UD |
1523 | |
1524 | /* Already initialized? */ | |
9756dfe1 | 1525 | int __malloc_initialized = -1; |
f65fd747 UD |
1526 | |
1527 | ||
ca34d7a7 UD |
1528 | /* The following two functions are registered via thread_atfork() to |
1529 | make sure that the mutexes remain in a consistent state in the | |
1530 | fork()ed version of a thread. Also adapt the malloc and free hooks | |
1531 | temporarily, because the `atfork' handler mechanism may use | |
1532 | malloc/free internally (e.g. in LinuxThreads). */ | |
1533 | ||
dfd2257a | 1534 | #if defined _LIBC || defined MALLOC_HOOKS |
a2b08ee5 UD |
1535 | static __malloc_ptr_t (*save_malloc_hook) __MALLOC_P ((size_t __size, |
1536 | const __malloc_ptr_t)); | |
1537 | static void (*save_free_hook) __MALLOC_P ((__malloc_ptr_t __ptr, | |
1538 | const __malloc_ptr_t)); | |
1539 | static Void_t* save_arena; | |
a2b08ee5 | 1540 | #endif |
ca34d7a7 UD |
1541 | |
1542 | static void | |
1543 | ptmalloc_lock_all __MALLOC_P((void)) | |
1544 | { | |
1545 | arena *ar_ptr; | |
1546 | ||
1547 | (void)mutex_lock(&list_lock); | |
1548 | for(ar_ptr = &main_arena;;) { | |
1549 | (void)mutex_lock(&ar_ptr->mutex); | |
1550 | ar_ptr = ar_ptr->next; | |
1551 | if(ar_ptr == &main_arena) break; | |
1552 | } | |
dfd2257a | 1553 | #if defined _LIBC || defined MALLOC_HOOKS |
ca34d7a7 UD |
1554 | save_malloc_hook = __malloc_hook; |
1555 | save_free_hook = __free_hook; | |
1556 | __malloc_hook = malloc_atfork; | |
1557 | __free_hook = free_atfork; | |
1558 | /* Only the current thread may perform malloc/free calls now. */ | |
1559 | tsd_getspecific(arena_key, save_arena); | |
1560 | tsd_setspecific(arena_key, (Void_t*)0); | |
1561 | #endif | |
1562 | } | |
1563 | ||
1564 | static void | |
1565 | ptmalloc_unlock_all __MALLOC_P((void)) | |
1566 | { | |
1567 | arena *ar_ptr; | |
1568 | ||
dfd2257a | 1569 | #if defined _LIBC || defined MALLOC_HOOKS |
ca34d7a7 UD |
1570 | tsd_setspecific(arena_key, save_arena); |
1571 | __malloc_hook = save_malloc_hook; | |
1572 | __free_hook = save_free_hook; | |
1573 | #endif | |
1574 | for(ar_ptr = &main_arena;;) { | |
1575 | (void)mutex_unlock(&ar_ptr->mutex); | |
1576 | ar_ptr = ar_ptr->next; | |
1577 | if(ar_ptr == &main_arena) break; | |
1578 | } | |
1579 | (void)mutex_unlock(&list_lock); | |
1580 | } | |
1581 | ||
f65fd747 UD |
1582 | /* Initialization routine. */ |
1583 | #if defined(_LIBC) | |
10dc2a90 | 1584 | #if 0 |
f65fd747 | 1585 | static void ptmalloc_init __MALLOC_P ((void)) __attribute__ ((constructor)); |
10dc2a90 | 1586 | #endif |
f65fd747 UD |
1587 | |
1588 | static void | |
1589 | ptmalloc_init __MALLOC_P((void)) | |
1590 | #else | |
1591 | void | |
1592 | ptmalloc_init __MALLOC_P((void)) | |
1593 | #endif | |
1594 | { | |
dfd2257a | 1595 | #if defined _LIBC || defined MALLOC_HOOKS |
10dc2a90 UD |
1596 | const char* s; |
1597 | #endif | |
f65fd747 | 1598 | |
9756dfe1 UD |
1599 | if(__malloc_initialized >= 0) return; |
1600 | __malloc_initialized = 0; | |
dfd2257a | 1601 | #if defined _LIBC || defined MALLOC_HOOKS |
7e3be507 UD |
1602 | /* With some threads implementations, creating thread-specific data |
1603 | or initializing a mutex may call malloc() itself. Provide a | |
1604 | simple starter version (realloc() won't work). */ | |
1605 | save_malloc_hook = __malloc_hook; | |
1606 | save_free_hook = __free_hook; | |
1607 | __malloc_hook = malloc_starter; | |
1608 | __free_hook = free_starter; | |
1609 | #endif | |
dfd2257a | 1610 | #if defined _LIBC && !defined NO_THREADS |
8a4b65b4 | 1611 | /* Initialize the pthreads interface. */ |
f65fd747 | 1612 | if (__pthread_initialize != NULL) |
8a4b65b4 | 1613 | __pthread_initialize(); |
f65fd747 | 1614 | #endif |
8a4b65b4 | 1615 | #ifndef NO_THREADS |
10dc2a90 UD |
1616 | mutex_init(&main_arena.mutex); |
1617 | mutex_init(&list_lock); | |
1618 | tsd_key_create(&arena_key, NULL); | |
1619 | tsd_setspecific(arena_key, (Void_t *)&main_arena); | |
ca34d7a7 | 1620 | thread_atfork(ptmalloc_lock_all, ptmalloc_unlock_all, ptmalloc_unlock_all); |
10dc2a90 | 1621 | #endif |
dfd2257a | 1622 | #if defined _LIBC || defined MALLOC_HOOKS |
831372e7 UD |
1623 | if((s = getenv("MALLOC_TRIM_THRESHOLD_"))) |
1624 | mALLOPt(M_TRIM_THRESHOLD, atoi(s)); | |
1625 | if((s = getenv("MALLOC_TOP_PAD_"))) | |
1626 | mALLOPt(M_TOP_PAD, atoi(s)); | |
1627 | if((s = getenv("MALLOC_MMAP_THRESHOLD_"))) | |
1628 | mALLOPt(M_MMAP_THRESHOLD, atoi(s)); | |
1629 | if((s = getenv("MALLOC_MMAP_MAX_"))) | |
1630 | mALLOPt(M_MMAP_MAX, atoi(s)); | |
10dc2a90 | 1631 | s = getenv("MALLOC_CHECK_"); |
7e3be507 UD |
1632 | __malloc_hook = save_malloc_hook; |
1633 | __free_hook = save_free_hook; | |
10dc2a90 | 1634 | if(s) { |
831372e7 UD |
1635 | if(s[0]) mALLOPt(M_CHECK_ACTION, (int)(s[0] - '0')); |
1636 | __malloc_check_init(); | |
f65fd747 | 1637 | } |
10dc2a90 UD |
1638 | if(__malloc_initialize_hook != NULL) |
1639 | (*__malloc_initialize_hook)(); | |
1640 | #endif | |
9756dfe1 | 1641 | __malloc_initialized = 1; |
f65fd747 UD |
1642 | } |
1643 | ||
ca34d7a7 UD |
1644 | /* There are platforms (e.g. Hurd) with a link-time hook mechanism. */ |
1645 | #ifdef thread_atfork_static | |
1646 | thread_atfork_static(ptmalloc_lock_all, ptmalloc_unlock_all, \ | |
1647 | ptmalloc_unlock_all) | |
1648 | #endif | |
1649 | ||
dfd2257a | 1650 | #if defined _LIBC || defined MALLOC_HOOKS |
10dc2a90 UD |
1651 | |
1652 | /* Hooks for debugging versions. The initial hooks just call the | |
1653 | initialization routine, then do the normal work. */ | |
1654 | ||
1655 | static Void_t* | |
a2b08ee5 UD |
1656 | #ifdef _LIBC |
1657 | malloc_hook_ini(size_t sz, const __malloc_ptr_t caller) | |
1658 | #else | |
10dc2a90 UD |
1659 | #if __STD_C |
1660 | malloc_hook_ini(size_t sz) | |
1661 | #else | |
1662 | malloc_hook_ini(sz) size_t sz; | |
1663 | #endif | |
a2b08ee5 | 1664 | #endif |
10dc2a90 UD |
1665 | { |
1666 | __malloc_hook = NULL; | |
1667 | __realloc_hook = NULL; | |
1668 | __memalign_hook = NULL; | |
1669 | ptmalloc_init(); | |
1670 | return mALLOc(sz); | |
1671 | } | |
1672 | ||
1673 | static Void_t* | |
1674 | #if __STD_C | |
dfd2257a | 1675 | realloc_hook_ini(Void_t* ptr, size_t sz, const __malloc_ptr_t caller) |
10dc2a90 | 1676 | #else |
dfd2257a UD |
1677 | realloc_hook_ini(ptr, sz, caller) |
1678 | Void_t* ptr; size_t sz; const __malloc_ptr_t caller; | |
a2b08ee5 | 1679 | #endif |
10dc2a90 UD |
1680 | { |
1681 | __malloc_hook = NULL; | |
1682 | __realloc_hook = NULL; | |
1683 | __memalign_hook = NULL; | |
1684 | ptmalloc_init(); | |
1685 | return rEALLOc(ptr, sz); | |
1686 | } | |
1687 | ||
1688 | static Void_t* | |
1689 | #if __STD_C | |
dfd2257a | 1690 | memalign_hook_ini(size_t sz, size_t alignment, const __malloc_ptr_t caller) |
10dc2a90 | 1691 | #else |
dfd2257a UD |
1692 | memalign_hook_ini(sz, alignment, caller) |
1693 | size_t sz; size_t alignment; const __malloc_ptr_t caller; | |
a2b08ee5 | 1694 | #endif |
10dc2a90 UD |
1695 | { |
1696 | __malloc_hook = NULL; | |
1697 | __realloc_hook = NULL; | |
1698 | __memalign_hook = NULL; | |
1699 | ptmalloc_init(); | |
1700 | return mEMALIGn(sz, alignment); | |
1701 | } | |
1702 | ||
831372e7 | 1703 | void weak_variable (*__malloc_initialize_hook) __MALLOC_P ((void)) = NULL; |
a2b08ee5 UD |
1704 | void weak_variable (*__free_hook) __MALLOC_P ((__malloc_ptr_t __ptr, |
1705 | const __malloc_ptr_t)) = NULL; | |
1706 | __malloc_ptr_t weak_variable (*__malloc_hook) | |
1707 | __MALLOC_P ((size_t __size, const __malloc_ptr_t)) = malloc_hook_ini; | |
1708 | __malloc_ptr_t weak_variable (*__realloc_hook) | |
1709 | __MALLOC_P ((__malloc_ptr_t __ptr, size_t __size, const __malloc_ptr_t)) | |
1710 | = realloc_hook_ini; | |
1711 | __malloc_ptr_t weak_variable (*__memalign_hook) | |
1712 | __MALLOC_P ((size_t __size, size_t __alignment, const __malloc_ptr_t)) | |
1713 | = memalign_hook_ini; | |
1228ed5c | 1714 | void weak_variable (*__after_morecore_hook) __MALLOC_P ((void)) = NULL; |
10dc2a90 UD |
1715 | |
1716 | /* Activate a standard set of debugging hooks. */ | |
1717 | void | |
831372e7 | 1718 | __malloc_check_init() |
10dc2a90 UD |
1719 | { |
1720 | __malloc_hook = malloc_check; | |
1721 | __free_hook = free_check; | |
1722 | __realloc_hook = realloc_check; | |
1723 | __memalign_hook = memalign_check; | |
7e3be507 UD |
1724 | if(check_action == 1) |
1725 | fprintf(stderr, "malloc: using debugging hooks\n"); | |
10dc2a90 UD |
1726 | } |
1727 | ||
1728 | #endif | |
1729 | ||
f65fd747 UD |
1730 | |
1731 | \f | |
1732 | ||
1733 | ||
1734 | /* Routines dealing with mmap(). */ | |
1735 | ||
1736 | #if HAVE_MMAP | |
1737 | ||
1738 | #ifndef MAP_ANONYMOUS | |
1739 | ||
1740 | static int dev_zero_fd = -1; /* Cached file descriptor for /dev/zero. */ | |
1741 | ||
1742 | #define MMAP(size, prot) ((dev_zero_fd < 0) ? \ | |
1743 | (dev_zero_fd = open("/dev/zero", O_RDWR), \ | |
1744 | mmap(0, (size), (prot), MAP_PRIVATE, dev_zero_fd, 0)) : \ | |
1745 | mmap(0, (size), (prot), MAP_PRIVATE, dev_zero_fd, 0)) | |
1746 | ||
1747 | #else | |
1748 | ||
1749 | #define MMAP(size, prot) \ | |
1750 | (mmap(0, (size), (prot), MAP_PRIVATE|MAP_ANONYMOUS, -1, 0)) | |
1751 | ||
1752 | #endif | |
1753 | ||
dfd2257a UD |
1754 | #if defined __GNUC__ && __GNUC__ >= 2 |
1755 | /* This function is only called from one place, inline it. */ | |
1756 | inline | |
1757 | #endif | |
af6f3906 | 1758 | static mchunkptr |
dfd2257a | 1759 | internal_function |
f65fd747 | 1760 | #if __STD_C |
dfd2257a | 1761 | mmap_chunk(size_t size) |
f65fd747 | 1762 | #else |
dfd2257a | 1763 | mmap_chunk(size) size_t size; |
f65fd747 UD |
1764 | #endif |
1765 | { | |
1766 | size_t page_mask = malloc_getpagesize - 1; | |
1767 | mchunkptr p; | |
1768 | ||
1769 | if(n_mmaps >= n_mmaps_max) return 0; /* too many regions */ | |
1770 | ||
1771 | /* For mmapped chunks, the overhead is one SIZE_SZ unit larger, because | |
1772 | * there is no following chunk whose prev_size field could be used. | |
1773 | */ | |
1774 | size = (size + SIZE_SZ + page_mask) & ~page_mask; | |
1775 | ||
1776 | p = (mchunkptr)MMAP(size, PROT_READ|PROT_WRITE); | |
0413b54c | 1777 | if(p == (mchunkptr) MAP_FAILED) return 0; |
f65fd747 UD |
1778 | |
1779 | n_mmaps++; | |
1780 | if (n_mmaps > max_n_mmaps) max_n_mmaps = n_mmaps; | |
1781 | ||
1782 | /* We demand that eight bytes into a page must be 8-byte aligned. */ | |
1783 | assert(aligned_OK(chunk2mem(p))); | |
1784 | ||
1785 | /* The offset to the start of the mmapped region is stored | |
1786 | * in the prev_size field of the chunk; normally it is zero, | |
1787 | * but that can be changed in memalign(). | |
1788 | */ | |
1789 | p->prev_size = 0; | |
1790 | set_head(p, size|IS_MMAPPED); | |
1791 | ||
1792 | mmapped_mem += size; | |
1793 | if ((unsigned long)mmapped_mem > (unsigned long)max_mmapped_mem) | |
1794 | max_mmapped_mem = mmapped_mem; | |
8a4b65b4 | 1795 | #ifdef NO_THREADS |
f65fd747 UD |
1796 | if ((unsigned long)(mmapped_mem + sbrked_mem) > (unsigned long)max_total_mem) |
1797 | max_total_mem = mmapped_mem + sbrked_mem; | |
8a4b65b4 | 1798 | #endif |
f65fd747 UD |
1799 | return p; |
1800 | } | |
1801 | ||
1802 | #if __STD_C | |
1803 | static void munmap_chunk(mchunkptr p) | |
1804 | #else | |
1805 | static void munmap_chunk(p) mchunkptr p; | |
1806 | #endif | |
1807 | { | |
1808 | INTERNAL_SIZE_T size = chunksize(p); | |
1809 | int ret; | |
1810 | ||
1811 | assert (chunk_is_mmapped(p)); | |
1812 | assert(! ((char*)p >= sbrk_base && (char*)p < sbrk_base + sbrked_mem)); | |
1813 | assert((n_mmaps > 0)); | |
1814 | assert(((p->prev_size + size) & (malloc_getpagesize-1)) == 0); | |
1815 | ||
1816 | n_mmaps--; | |
1817 | mmapped_mem -= (size + p->prev_size); | |
1818 | ||
1819 | ret = munmap((char *)p - p->prev_size, size + p->prev_size); | |
1820 | ||
1821 | /* munmap returns non-zero on failure */ | |
1822 | assert(ret == 0); | |
1823 | } | |
1824 | ||
1825 | #if HAVE_MREMAP | |
1826 | ||
1827 | #if __STD_C | |
1828 | static mchunkptr mremap_chunk(mchunkptr p, size_t new_size) | |
1829 | #else | |
1830 | static mchunkptr mremap_chunk(p, new_size) mchunkptr p; size_t new_size; | |
1831 | #endif | |
1832 | { | |
1833 | size_t page_mask = malloc_getpagesize - 1; | |
1834 | INTERNAL_SIZE_T offset = p->prev_size; | |
1835 | INTERNAL_SIZE_T size = chunksize(p); | |
1836 | char *cp; | |
1837 | ||
1838 | assert (chunk_is_mmapped(p)); | |
1839 | assert(! ((char*)p >= sbrk_base && (char*)p < sbrk_base + sbrked_mem)); | |
1840 | assert((n_mmaps > 0)); | |
1841 | assert(((size + offset) & (malloc_getpagesize-1)) == 0); | |
1842 | ||
1843 | /* Note the extra SIZE_SZ overhead as in mmap_chunk(). */ | |
1844 | new_size = (new_size + offset + SIZE_SZ + page_mask) & ~page_mask; | |
1845 | ||
1846 | cp = (char *)mremap((char *)p - offset, size + offset, new_size, | |
1847 | MREMAP_MAYMOVE); | |
1848 | ||
1849 | if (cp == (char *)-1) return 0; | |
1850 | ||
1851 | p = (mchunkptr)(cp + offset); | |
1852 | ||
1853 | assert(aligned_OK(chunk2mem(p))); | |
1854 | ||
1855 | assert((p->prev_size == offset)); | |
1856 | set_head(p, (new_size - offset)|IS_MMAPPED); | |
1857 | ||
1858 | mmapped_mem -= size + offset; | |
1859 | mmapped_mem += new_size; | |
1860 | if ((unsigned long)mmapped_mem > (unsigned long)max_mmapped_mem) | |
1861 | max_mmapped_mem = mmapped_mem; | |
8a4b65b4 | 1862 | #ifdef NO_THREADS |
f65fd747 UD |
1863 | if ((unsigned long)(mmapped_mem + sbrked_mem) > (unsigned long)max_total_mem) |
1864 | max_total_mem = mmapped_mem + sbrked_mem; | |
8a4b65b4 | 1865 | #endif |
f65fd747 UD |
1866 | return p; |
1867 | } | |
1868 | ||
1869 | #endif /* HAVE_MREMAP */ | |
1870 | ||
1871 | #endif /* HAVE_MMAP */ | |
1872 | ||
1873 | \f | |
1874 | ||
1875 | /* Managing heaps and arenas (for concurrent threads) */ | |
1876 | ||
1877 | #ifndef NO_THREADS | |
1878 | ||
1879 | /* Create a new heap. size is automatically rounded up to a multiple | |
1880 | of the page size. */ | |
1881 | ||
1882 | static heap_info * | |
dfd2257a | 1883 | internal_function |
f65fd747 UD |
1884 | #if __STD_C |
1885 | new_heap(size_t size) | |
1886 | #else | |
1887 | new_heap(size) size_t size; | |
1888 | #endif | |
1889 | { | |
1890 | size_t page_mask = malloc_getpagesize - 1; | |
1891 | char *p1, *p2; | |
1892 | unsigned long ul; | |
1893 | heap_info *h; | |
1894 | ||
7799b7b3 | 1895 | if(size+top_pad < HEAP_MIN_SIZE) |
f65fd747 | 1896 | size = HEAP_MIN_SIZE; |
7799b7b3 UD |
1897 | else if(size+top_pad <= HEAP_MAX_SIZE) |
1898 | size += top_pad; | |
1899 | else if(size > HEAP_MAX_SIZE) | |
f65fd747 | 1900 | return 0; |
7799b7b3 UD |
1901 | else |
1902 | size = HEAP_MAX_SIZE; | |
1903 | size = (size + page_mask) & ~page_mask; | |
1904 | ||
f65fd747 | 1905 | p1 = (char *)MMAP(HEAP_MAX_SIZE<<1, PROT_NONE); |
0413b54c | 1906 | if(p1 == MAP_FAILED) |
f65fd747 UD |
1907 | return 0; |
1908 | p2 = (char *)(((unsigned long)p1 + HEAP_MAX_SIZE) & ~(HEAP_MAX_SIZE-1)); | |
1909 | ul = p2 - p1; | |
1910 | munmap(p1, ul); | |
1911 | munmap(p2 + HEAP_MAX_SIZE, HEAP_MAX_SIZE - ul); | |
1912 | if(mprotect(p2, size, PROT_READ|PROT_WRITE) != 0) { | |
1913 | munmap(p2, HEAP_MAX_SIZE); | |
1914 | return 0; | |
1915 | } | |
1916 | h = (heap_info *)p2; | |
1917 | h->size = size; | |
1918 | THREAD_STAT(stat_n_heaps++); | |
1919 | return h; | |
1920 | } | |
1921 | ||
1922 | /* Grow or shrink a heap. size is automatically rounded up to a | |
8a4b65b4 | 1923 | multiple of the page size if it is positive. */ |
f65fd747 UD |
1924 | |
1925 | static int | |
1926 | #if __STD_C | |
1927 | grow_heap(heap_info *h, long diff) | |
1928 | #else | |
1929 | grow_heap(h, diff) heap_info *h; long diff; | |
1930 | #endif | |
1931 | { | |
1932 | size_t page_mask = malloc_getpagesize - 1; | |
1933 | long new_size; | |
1934 | ||
1935 | if(diff >= 0) { | |
1936 | diff = (diff + page_mask) & ~page_mask; | |
1937 | new_size = (long)h->size + diff; | |
1938 | if(new_size > HEAP_MAX_SIZE) | |
1939 | return -1; | |
1940 | if(mprotect((char *)h + h->size, diff, PROT_READ|PROT_WRITE) != 0) | |
1941 | return -2; | |
1942 | } else { | |
1943 | new_size = (long)h->size + diff; | |
8a4b65b4 | 1944 | if(new_size < (long)sizeof(*h)) |
f65fd747 UD |
1945 | return -1; |
1946 | if(mprotect((char *)h + new_size, -diff, PROT_NONE) != 0) | |
1947 | return -2; | |
1948 | } | |
1949 | h->size = new_size; | |
1950 | return 0; | |
1951 | } | |
1952 | ||
8a4b65b4 UD |
1953 | /* Delete a heap. */ |
1954 | ||
1955 | #define delete_heap(heap) munmap((char*)(heap), HEAP_MAX_SIZE) | |
1956 | ||
f65fd747 UD |
1957 | /* arena_get() acquires an arena and locks the corresponding mutex. |
1958 | First, try the one last locked successfully by this thread. (This | |
1959 | is the common case and handled with a macro for speed.) Then, loop | |
7e3be507 UD |
1960 | once over the circularly linked list of arenas. If no arena is |
1961 | readily available, create a new one. */ | |
f65fd747 UD |
1962 | |
1963 | #define arena_get(ptr, size) do { \ | |
1964 | Void_t *vptr = NULL; \ | |
1965 | ptr = (arena *)tsd_getspecific(arena_key, vptr); \ | |
1966 | if(ptr && !mutex_trylock(&ptr->mutex)) { \ | |
8a4b65b4 | 1967 | THREAD_STAT(++(ptr->stat_lock_direct)); \ |
7e3be507 | 1968 | } else \ |
f65fd747 | 1969 | ptr = arena_get2(ptr, (size)); \ |
f65fd747 UD |
1970 | } while(0) |
1971 | ||
1972 | static arena * | |
dfd2257a | 1973 | internal_function |
f65fd747 UD |
1974 | #if __STD_C |
1975 | arena_get2(arena *a_tsd, size_t size) | |
1976 | #else | |
1977 | arena_get2(a_tsd, size) arena *a_tsd; size_t size; | |
1978 | #endif | |
1979 | { | |
1980 | arena *a; | |
1981 | heap_info *h; | |
1982 | char *ptr; | |
1983 | int i; | |
1984 | unsigned long misalign; | |
1985 | ||
7e3be507 UD |
1986 | if(!a_tsd) |
1987 | a = a_tsd = &main_arena; | |
1988 | else { | |
1989 | a = a_tsd->next; | |
1990 | if(!a) { | |
1991 | /* This can only happen while initializing the new arena. */ | |
1992 | (void)mutex_lock(&main_arena.mutex); | |
1993 | THREAD_STAT(++(main_arena.stat_lock_wait)); | |
1994 | return &main_arena; | |
f65fd747 | 1995 | } |
8a4b65b4 | 1996 | } |
7e3be507 UD |
1997 | |
1998 | /* Check the global, circularly linked list for available arenas. */ | |
1999 | do { | |
2000 | if(!mutex_trylock(&a->mutex)) { | |
2001 | THREAD_STAT(++(a->stat_lock_loop)); | |
2002 | tsd_setspecific(arena_key, (Void_t *)a); | |
2003 | return a; | |
2004 | } | |
2005 | a = a->next; | |
2006 | } while(a != a_tsd); | |
f65fd747 UD |
2007 | |
2008 | /* Nothing immediately available, so generate a new arena. */ | |
2009 | h = new_heap(size + (sizeof(*h) + sizeof(*a) + MALLOC_ALIGNMENT)); | |
2010 | if(!h) | |
2011 | return 0; | |
2012 | a = h->ar_ptr = (arena *)(h+1); | |
2013 | for(i=0; i<NAV; i++) | |
2014 | init_bin(a, i); | |
7e3be507 | 2015 | a->next = NULL; |
8a4b65b4 | 2016 | a->size = h->size; |
7e3be507 | 2017 | tsd_setspecific(arena_key, (Void_t *)a); |
f65fd747 UD |
2018 | mutex_init(&a->mutex); |
2019 | i = mutex_lock(&a->mutex); /* remember result */ | |
2020 | ||
2021 | /* Set up the top chunk, with proper alignment. */ | |
2022 | ptr = (char *)(a + 1); | |
2023 | misalign = (unsigned long)chunk2mem(ptr) & MALLOC_ALIGN_MASK; | |
2024 | if (misalign > 0) | |
2025 | ptr += MALLOC_ALIGNMENT - misalign; | |
2026 | top(a) = (mchunkptr)ptr; | |
8a4b65b4 | 2027 | set_head(top(a), (((char*)h + h->size) - ptr) | PREV_INUSE); |
f65fd747 UD |
2028 | |
2029 | /* Add the new arena to the list. */ | |
2030 | (void)mutex_lock(&list_lock); | |
2031 | a->next = main_arena.next; | |
2032 | main_arena.next = a; | |
f65fd747 UD |
2033 | (void)mutex_unlock(&list_lock); |
2034 | ||
2035 | if(i) /* locking failed; keep arena for further attempts later */ | |
2036 | return 0; | |
2037 | ||
8a4b65b4 | 2038 | THREAD_STAT(++(a->stat_lock_loop)); |
f65fd747 UD |
2039 | return a; |
2040 | } | |
2041 | ||
2042 | /* find the heap and corresponding arena for a given ptr */ | |
2043 | ||
2044 | #define heap_for_ptr(ptr) \ | |
2045 | ((heap_info *)((unsigned long)(ptr) & ~(HEAP_MAX_SIZE-1))) | |
2046 | #define arena_for_ptr(ptr) \ | |
2047 | (((mchunkptr)(ptr) < top(&main_arena) && (char *)(ptr) >= sbrk_base) ? \ | |
2048 | &main_arena : heap_for_ptr(ptr)->ar_ptr) | |
2049 | ||
2050 | #else /* defined(NO_THREADS) */ | |
2051 | ||
2052 | /* Without concurrent threads, there is only one arena. */ | |
2053 | ||
2054 | #define arena_get(ptr, sz) (ptr = &main_arena) | |
2055 | #define arena_for_ptr(ptr) (&main_arena) | |
2056 | ||
2057 | #endif /* !defined(NO_THREADS) */ | |
2058 | ||
2059 | \f | |
2060 | ||
2061 | /* | |
2062 | Debugging support | |
2063 | */ | |
2064 | ||
2065 | #if MALLOC_DEBUG | |
2066 | ||
2067 | ||
2068 | /* | |
2069 | These routines make a number of assertions about the states | |
2070 | of data structures that should be true at all times. If any | |
2071 | are not true, it's very likely that a user program has somehow | |
2072 | trashed memory. (It's also possible that there is a coding error | |
2073 | in malloc. In which case, please report it!) | |
2074 | */ | |
2075 | ||
2076 | #if __STD_C | |
2077 | static void do_check_chunk(arena *ar_ptr, mchunkptr p) | |
2078 | #else | |
2079 | static void do_check_chunk(ar_ptr, p) arena *ar_ptr; mchunkptr p; | |
2080 | #endif | |
2081 | { | |
2082 | INTERNAL_SIZE_T sz = p->size & ~PREV_INUSE; | |
2083 | ||
2084 | /* No checkable chunk is mmapped */ | |
2085 | assert(!chunk_is_mmapped(p)); | |
2086 | ||
2087 | #ifndef NO_THREADS | |
2088 | if(ar_ptr != &main_arena) { | |
2089 | heap_info *heap = heap_for_ptr(p); | |
2090 | assert(heap->ar_ptr == ar_ptr); | |
2091 | assert((char *)p + sz <= (char *)heap + heap->size); | |
2092 | return; | |
2093 | } | |
2094 | #endif | |
2095 | ||
2096 | /* Check for legal address ... */ | |
2097 | assert((char*)p >= sbrk_base); | |
2098 | if (p != top(ar_ptr)) | |
2099 | assert((char*)p + sz <= (char*)top(ar_ptr)); | |
2100 | else | |
2101 | assert((char*)p + sz <= sbrk_base + sbrked_mem); | |
2102 | ||
2103 | } | |
2104 | ||
2105 | ||
2106 | #if __STD_C | |
2107 | static void do_check_free_chunk(arena *ar_ptr, mchunkptr p) | |
2108 | #else | |
2109 | static void do_check_free_chunk(ar_ptr, p) arena *ar_ptr; mchunkptr p; | |
2110 | #endif | |
2111 | { | |
2112 | INTERNAL_SIZE_T sz = p->size & ~PREV_INUSE; | |
2113 | mchunkptr next = chunk_at_offset(p, sz); | |
2114 | ||
2115 | do_check_chunk(ar_ptr, p); | |
2116 | ||
2117 | /* Check whether it claims to be free ... */ | |
2118 | assert(!inuse(p)); | |
2119 | ||
8a4b65b4 UD |
2120 | /* Must have OK size and fields */ |
2121 | assert((long)sz >= (long)MINSIZE); | |
2122 | assert((sz & MALLOC_ALIGN_MASK) == 0); | |
2123 | assert(aligned_OK(chunk2mem(p))); | |
2124 | /* ... matching footer field */ | |
2125 | assert(next->prev_size == sz); | |
2126 | /* ... and is fully consolidated */ | |
2127 | assert(prev_inuse(p)); | |
2128 | assert (next == top(ar_ptr) || inuse(next)); | |
2129 | ||
2130 | /* ... and has minimally sane links */ | |
2131 | assert(p->fd->bk == p); | |
2132 | assert(p->bk->fd == p); | |
f65fd747 UD |
2133 | } |
2134 | ||
2135 | #if __STD_C | |
2136 | static void do_check_inuse_chunk(arena *ar_ptr, mchunkptr p) | |
2137 | #else | |
2138 | static void do_check_inuse_chunk(ar_ptr, p) arena *ar_ptr; mchunkptr p; | |
2139 | #endif | |
2140 | { | |
2141 | mchunkptr next = next_chunk(p); | |
2142 | do_check_chunk(ar_ptr, p); | |
2143 | ||
2144 | /* Check whether it claims to be in use ... */ | |
2145 | assert(inuse(p)); | |
2146 | ||
8a4b65b4 UD |
2147 | /* ... whether its size is OK (it might be a fencepost) ... */ |
2148 | assert(chunksize(p) >= MINSIZE || next->size == (0|PREV_INUSE)); | |
2149 | ||
f65fd747 UD |
2150 | /* ... and is surrounded by OK chunks. |
2151 | Since more things can be checked with free chunks than inuse ones, | |
2152 | if an inuse chunk borders them and debug is on, it's worth doing them. | |
2153 | */ | |
2154 | if (!prev_inuse(p)) | |
2155 | { | |
2156 | mchunkptr prv = prev_chunk(p); | |
2157 | assert(next_chunk(prv) == p); | |
2158 | do_check_free_chunk(ar_ptr, prv); | |
2159 | } | |
2160 | if (next == top(ar_ptr)) | |
2161 | { | |
2162 | assert(prev_inuse(next)); | |
2163 | assert(chunksize(next) >= MINSIZE); | |
2164 | } | |
2165 | else if (!inuse(next)) | |
2166 | do_check_free_chunk(ar_ptr, next); | |
2167 | ||
2168 | } | |
2169 | ||
2170 | #if __STD_C | |
2171 | static void do_check_malloced_chunk(arena *ar_ptr, | |
2172 | mchunkptr p, INTERNAL_SIZE_T s) | |
2173 | #else | |
2174 | static void do_check_malloced_chunk(ar_ptr, p, s) | |
2175 | arena *ar_ptr; mchunkptr p; INTERNAL_SIZE_T s; | |
2176 | #endif | |
2177 | { | |
2178 | INTERNAL_SIZE_T sz = p->size & ~PREV_INUSE; | |
2179 | long room = sz - s; | |
2180 | ||
2181 | do_check_inuse_chunk(ar_ptr, p); | |
2182 | ||
2183 | /* Legal size ... */ | |
2184 | assert((long)sz >= (long)MINSIZE); | |
2185 | assert((sz & MALLOC_ALIGN_MASK) == 0); | |
2186 | assert(room >= 0); | |
2187 | assert(room < (long)MINSIZE); | |
2188 | ||
2189 | /* ... and alignment */ | |
2190 | assert(aligned_OK(chunk2mem(p))); | |
2191 | ||
2192 | ||
2193 | /* ... and was allocated at front of an available chunk */ | |
2194 | assert(prev_inuse(p)); | |
2195 | ||
2196 | } | |
2197 | ||
2198 | ||
2199 | #define check_free_chunk(A,P) do_check_free_chunk(A,P) | |
2200 | #define check_inuse_chunk(A,P) do_check_inuse_chunk(A,P) | |
2201 | #define check_chunk(A,P) do_check_chunk(A,P) | |
2202 | #define check_malloced_chunk(A,P,N) do_check_malloced_chunk(A,P,N) | |
2203 | #else | |
2204 | #define check_free_chunk(A,P) | |
2205 | #define check_inuse_chunk(A,P) | |
2206 | #define check_chunk(A,P) | |
2207 | #define check_malloced_chunk(A,P,N) | |
2208 | #endif | |
2209 | ||
2210 | \f | |
2211 | ||
2212 | /* | |
2213 | Macro-based internal utilities | |
2214 | */ | |
2215 | ||
2216 | ||
2217 | /* | |
2218 | Linking chunks in bin lists. | |
2219 | Call these only with variables, not arbitrary expressions, as arguments. | |
2220 | */ | |
2221 | ||
2222 | /* | |
2223 | Place chunk p of size s in its bin, in size order, | |
2224 | putting it ahead of others of same size. | |
2225 | */ | |
2226 | ||
2227 | ||
2228 | #define frontlink(A, P, S, IDX, BK, FD) \ | |
2229 | { \ | |
2230 | if (S < MAX_SMALLBIN_SIZE) \ | |
2231 | { \ | |
2232 | IDX = smallbin_index(S); \ | |
2233 | mark_binblock(A, IDX); \ | |
2234 | BK = bin_at(A, IDX); \ | |
2235 | FD = BK->fd; \ | |
2236 | P->bk = BK; \ | |
2237 | P->fd = FD; \ | |
2238 | FD->bk = BK->fd = P; \ | |
2239 | } \ | |
2240 | else \ | |
2241 | { \ | |
2242 | IDX = bin_index(S); \ | |
2243 | BK = bin_at(A, IDX); \ | |
2244 | FD = BK->fd; \ | |
2245 | if (FD == BK) mark_binblock(A, IDX); \ | |
2246 | else \ | |
2247 | { \ | |
2248 | while (FD != BK && S < chunksize(FD)) FD = FD->fd; \ | |
2249 | BK = FD->bk; \ | |
2250 | } \ | |
2251 | P->bk = BK; \ | |
2252 | P->fd = FD; \ | |
2253 | FD->bk = BK->fd = P; \ | |
2254 | } \ | |
2255 | } | |
2256 | ||
2257 | ||
2258 | /* take a chunk off a list */ | |
2259 | ||
2260 | #define unlink(P, BK, FD) \ | |
2261 | { \ | |
2262 | BK = P->bk; \ | |
2263 | FD = P->fd; \ | |
2264 | FD->bk = BK; \ | |
2265 | BK->fd = FD; \ | |
2266 | } \ | |
2267 | ||
2268 | /* Place p as the last remainder */ | |
2269 | ||
2270 | #define link_last_remainder(A, P) \ | |
2271 | { \ | |
2272 | last_remainder(A)->fd = last_remainder(A)->bk = P; \ | |
2273 | P->fd = P->bk = last_remainder(A); \ | |
2274 | } | |
2275 | ||
2276 | /* Clear the last_remainder bin */ | |
2277 | ||
2278 | #define clear_last_remainder(A) \ | |
2279 | (last_remainder(A)->fd = last_remainder(A)->bk = last_remainder(A)) | |
2280 | ||
2281 | ||
2282 | ||
2283 | \f | |
2284 | ||
2285 | /* | |
2286 | Extend the top-most chunk by obtaining memory from system. | |
2287 | Main interface to sbrk (but see also malloc_trim). | |
2288 | */ | |
2289 | ||
dfd2257a UD |
2290 | #if defined __GNUC__ && __GNUC__ >= 2 |
2291 | /* This function is called only from one place, inline it. */ | |
2292 | inline | |
2293 | #endif | |
af6f3906 | 2294 | static void |
dfd2257a | 2295 | internal_function |
f65fd747 | 2296 | #if __STD_C |
dfd2257a | 2297 | malloc_extend_top(arena *ar_ptr, INTERNAL_SIZE_T nb) |
f65fd747 | 2298 | #else |
dfd2257a | 2299 | malloc_extend_top(ar_ptr, nb) arena *ar_ptr; INTERNAL_SIZE_T nb; |
f65fd747 UD |
2300 | #endif |
2301 | { | |
2302 | unsigned long pagesz = malloc_getpagesize; | |
2303 | mchunkptr old_top = top(ar_ptr); /* Record state of old top */ | |
2304 | INTERNAL_SIZE_T old_top_size = chunksize(old_top); | |
2305 | INTERNAL_SIZE_T top_size; /* new size of top chunk */ | |
2306 | ||
2307 | #ifndef NO_THREADS | |
2308 | if(ar_ptr == &main_arena) { | |
2309 | #endif | |
2310 | ||
2311 | char* brk; /* return value from sbrk */ | |
2312 | INTERNAL_SIZE_T front_misalign; /* unusable bytes at front of sbrked space */ | |
2313 | INTERNAL_SIZE_T correction; /* bytes for 2nd sbrk call */ | |
2314 | char* new_brk; /* return of 2nd sbrk call */ | |
2315 | char* old_end = (char*)(chunk_at_offset(old_top, old_top_size)); | |
2316 | ||
2317 | /* Pad request with top_pad plus minimal overhead */ | |
2318 | INTERNAL_SIZE_T sbrk_size = nb + top_pad + MINSIZE; | |
2319 | ||
2320 | /* If not the first time through, round to preserve page boundary */ | |
2321 | /* Otherwise, we need to correct to a page size below anyway. */ | |
2322 | /* (We also correct below if an intervening foreign sbrk call.) */ | |
2323 | ||
2324 | if (sbrk_base != (char*)(-1)) | |
2325 | sbrk_size = (sbrk_size + (pagesz - 1)) & ~(pagesz - 1); | |
2326 | ||
2327 | brk = (char*)(MORECORE (sbrk_size)); | |
2328 | ||
2329 | /* Fail if sbrk failed or if a foreign sbrk call killed our space */ | |
2330 | if (brk == (char*)(MORECORE_FAILURE) || | |
2331 | (brk < old_end && old_top != initial_top(&main_arena))) | |
2332 | return; | |
2333 | ||
dfd2257a | 2334 | #if defined _LIBC || defined MALLOC_HOOKS |
1228ed5c UD |
2335 | /* Call the `morecore' hook if necessary. */ |
2336 | if (__after_morecore_hook) | |
2337 | (*__after_morecore_hook) (); | |
7799b7b3 | 2338 | #endif |
1228ed5c | 2339 | |
f65fd747 UD |
2340 | sbrked_mem += sbrk_size; |
2341 | ||
2342 | if (brk == old_end) { /* can just add bytes to current top */ | |
2343 | top_size = sbrk_size + old_top_size; | |
2344 | set_head(old_top, top_size | PREV_INUSE); | |
2345 | old_top = 0; /* don't free below */ | |
2346 | } else { | |
2347 | if (sbrk_base == (char*)(-1)) /* First time through. Record base */ | |
2348 | sbrk_base = brk; | |
2349 | else | |
2350 | /* Someone else called sbrk(). Count those bytes as sbrked_mem. */ | |
2351 | sbrked_mem += brk - (char*)old_end; | |
2352 | ||
2353 | /* Guarantee alignment of first new chunk made from this space */ | |
2354 | front_misalign = (unsigned long)chunk2mem(brk) & MALLOC_ALIGN_MASK; | |
2355 | if (front_misalign > 0) { | |
2356 | correction = (MALLOC_ALIGNMENT) - front_misalign; | |
2357 | brk += correction; | |
2358 | } else | |
2359 | correction = 0; | |
2360 | ||
2361 | /* Guarantee the next brk will be at a page boundary */ | |
2362 | correction += pagesz - ((unsigned long)(brk + sbrk_size) & (pagesz - 1)); | |
2363 | ||
2364 | /* Allocate correction */ | |
2365 | new_brk = (char*)(MORECORE (correction)); | |
2366 | if (new_brk == (char*)(MORECORE_FAILURE)) return; | |
2367 | ||
dfd2257a | 2368 | #if defined _LIBC || defined MALLOC_HOOKS |
1228ed5c UD |
2369 | /* Call the `morecore' hook if necessary. */ |
2370 | if (__after_morecore_hook) | |
7799b7b3 UD |
2371 | (*__after_morecore_hook) (); |
2372 | #endif | |
1228ed5c | 2373 | |
f65fd747 UD |
2374 | sbrked_mem += correction; |
2375 | ||
2376 | top(&main_arena) = (mchunkptr)brk; | |
2377 | top_size = new_brk - brk + correction; | |
2378 | set_head(top(&main_arena), top_size | PREV_INUSE); | |
2379 | ||
2380 | if (old_top == initial_top(&main_arena)) | |
2381 | old_top = 0; /* don't free below */ | |
2382 | } | |
2383 | ||
2384 | if ((unsigned long)sbrked_mem > (unsigned long)max_sbrked_mem) | |
2385 | max_sbrked_mem = sbrked_mem; | |
8a4b65b4 | 2386 | #ifdef NO_THREADS |
f65fd747 UD |
2387 | if ((unsigned long)(mmapped_mem + sbrked_mem) > |
2388 | (unsigned long)max_total_mem) | |
2389 | max_total_mem = mmapped_mem + sbrked_mem; | |
8a4b65b4 | 2390 | #endif |
f65fd747 UD |
2391 | |
2392 | #ifndef NO_THREADS | |
2393 | } else { /* ar_ptr != &main_arena */ | |
8a4b65b4 UD |
2394 | heap_info *old_heap, *heap; |
2395 | size_t old_heap_size; | |
f65fd747 UD |
2396 | |
2397 | if(old_top_size < MINSIZE) /* this should never happen */ | |
2398 | return; | |
2399 | ||
2400 | /* First try to extend the current heap. */ | |
2401 | if(MINSIZE + nb <= old_top_size) | |
2402 | return; | |
8a4b65b4 UD |
2403 | old_heap = heap_for_ptr(old_top); |
2404 | old_heap_size = old_heap->size; | |
2405 | if(grow_heap(old_heap, MINSIZE + nb - old_top_size) == 0) { | |
2406 | ar_ptr->size += old_heap->size - old_heap_size; | |
2407 | top_size = ((char *)old_heap + old_heap->size) - (char *)old_top; | |
f65fd747 UD |
2408 | set_head(old_top, top_size | PREV_INUSE); |
2409 | return; | |
2410 | } | |
2411 | ||
2412 | /* A new heap must be created. */ | |
7799b7b3 | 2413 | heap = new_heap(nb + (MINSIZE + sizeof(*heap))); |
f65fd747 UD |
2414 | if(!heap) |
2415 | return; | |
2416 | heap->ar_ptr = ar_ptr; | |
8a4b65b4 UD |
2417 | heap->prev = old_heap; |
2418 | ar_ptr->size += heap->size; | |
f65fd747 UD |
2419 | |
2420 | /* Set up the new top, so we can safely use chunk_free() below. */ | |
2421 | top(ar_ptr) = chunk_at_offset(heap, sizeof(*heap)); | |
2422 | top_size = heap->size - sizeof(*heap); | |
2423 | set_head(top(ar_ptr), top_size | PREV_INUSE); | |
2424 | } | |
2425 | #endif /* !defined(NO_THREADS) */ | |
2426 | ||
2427 | /* We always land on a page boundary */ | |
2428 | assert(((unsigned long)((char*)top(ar_ptr) + top_size) & (pagesz-1)) == 0); | |
2429 | ||
2430 | /* Setup fencepost and free the old top chunk. */ | |
2431 | if(old_top) { | |
8a4b65b4 UD |
2432 | /* The fencepost takes at least MINSIZE bytes, because it might |
2433 | become the top chunk again later. Note that a footer is set | |
2434 | up, too, although the chunk is marked in use. */ | |
2435 | old_top_size -= MINSIZE; | |
2436 | set_head(chunk_at_offset(old_top, old_top_size + 2*SIZE_SZ), 0|PREV_INUSE); | |
2437 | if(old_top_size >= MINSIZE) { | |
2438 | set_head(chunk_at_offset(old_top, old_top_size), (2*SIZE_SZ)|PREV_INUSE); | |
2439 | set_foot(chunk_at_offset(old_top, old_top_size), (2*SIZE_SZ)); | |
f65fd747 UD |
2440 | set_head_size(old_top, old_top_size); |
2441 | chunk_free(ar_ptr, old_top); | |
2442 | } else { | |
8a4b65b4 UD |
2443 | set_head(old_top, (old_top_size + 2*SIZE_SZ)|PREV_INUSE); |
2444 | set_foot(old_top, (old_top_size + 2*SIZE_SZ)); | |
f65fd747 UD |
2445 | } |
2446 | } | |
2447 | } | |
2448 | ||
2449 | ||
2450 | \f | |
2451 | ||
2452 | /* Main public routines */ | |
2453 | ||
2454 | ||
2455 | /* | |
8a4b65b4 | 2456 | Malloc Algorithm: |
f65fd747 UD |
2457 | |
2458 | The requested size is first converted into a usable form, `nb'. | |
2459 | This currently means to add 4 bytes overhead plus possibly more to | |
2460 | obtain 8-byte alignment and/or to obtain a size of at least | |
8a4b65b4 UD |
2461 | MINSIZE (currently 16, 24, or 32 bytes), the smallest allocatable |
2462 | size. (All fits are considered `exact' if they are within MINSIZE | |
2463 | bytes.) | |
f65fd747 UD |
2464 | |
2465 | From there, the first successful of the following steps is taken: | |
2466 | ||
2467 | 1. The bin corresponding to the request size is scanned, and if | |
2468 | a chunk of exactly the right size is found, it is taken. | |
2469 | ||
2470 | 2. The most recently remaindered chunk is used if it is big | |
2471 | enough. This is a form of (roving) first fit, used only in | |
2472 | the absence of exact fits. Runs of consecutive requests use | |
2473 | the remainder of the chunk used for the previous such request | |
2474 | whenever possible. This limited use of a first-fit style | |
2475 | allocation strategy tends to give contiguous chunks | |
2476 | coextensive lifetimes, which improves locality and can reduce | |
2477 | fragmentation in the long run. | |
2478 | ||
2479 | 3. Other bins are scanned in increasing size order, using a | |
2480 | chunk big enough to fulfill the request, and splitting off | |
2481 | any remainder. This search is strictly by best-fit; i.e., | |
2482 | the smallest (with ties going to approximately the least | |
2483 | recently used) chunk that fits is selected. | |
2484 | ||
2485 | 4. If large enough, the chunk bordering the end of memory | |
2486 | (`top') is split off. (This use of `top' is in accord with | |
2487 | the best-fit search rule. In effect, `top' is treated as | |
2488 | larger (and thus less well fitting) than any other available | |
2489 | chunk since it can be extended to be as large as necessary | |
2490 | (up to system limitations). | |
2491 | ||
2492 | 5. If the request size meets the mmap threshold and the | |
2493 | system supports mmap, and there are few enough currently | |
2494 | allocated mmapped regions, and a call to mmap succeeds, | |
2495 | the request is allocated via direct memory mapping. | |
2496 | ||
2497 | 6. Otherwise, the top of memory is extended by | |
2498 | obtaining more space from the system (normally using sbrk, | |
2499 | but definable to anything else via the MORECORE macro). | |
2500 | Memory is gathered from the system (in system page-sized | |
2501 | units) in a way that allows chunks obtained across different | |
2502 | sbrk calls to be consolidated, but does not require | |
2503 | contiguous memory. Thus, it should be safe to intersperse | |
2504 | mallocs with other sbrk calls. | |
2505 | ||
2506 | ||
2507 | All allocations are made from the the `lowest' part of any found | |
2508 | chunk. (The implementation invariant is that prev_inuse is | |
2509 | always true of any allocated chunk; i.e., that each allocated | |
2510 | chunk borders either a previously allocated and still in-use chunk, | |
2511 | or the base of its memory arena.) | |
2512 | ||
2513 | */ | |
2514 | ||
2515 | #if __STD_C | |
2516 | Void_t* mALLOc(size_t bytes) | |
2517 | #else | |
2518 | Void_t* mALLOc(bytes) size_t bytes; | |
2519 | #endif | |
2520 | { | |
2521 | arena *ar_ptr; | |
10dc2a90 | 2522 | INTERNAL_SIZE_T nb; /* padded request size */ |
f65fd747 UD |
2523 | mchunkptr victim; |
2524 | ||
dfd2257a | 2525 | #if defined _LIBC || defined MALLOC_HOOKS |
10dc2a90 UD |
2526 | if (__malloc_hook != NULL) { |
2527 | Void_t* result; | |
2528 | ||
dfd2257a | 2529 | #if defined __GNUC__ && __GNUC__ >= 2 |
a2b08ee5 UD |
2530 | result = (*__malloc_hook)(bytes, __builtin_return_address (0)); |
2531 | #else | |
dfd2257a | 2532 | result = (*__malloc_hook)(bytes, NULL); |
a2b08ee5 | 2533 | #endif |
10dc2a90 UD |
2534 | return result; |
2535 | } | |
2536 | #endif | |
2537 | ||
2538 | nb = request2size(bytes); | |
7799b7b3 | 2539 | arena_get(ar_ptr, nb); |
f65fd747 UD |
2540 | if(!ar_ptr) |
2541 | return 0; | |
2542 | victim = chunk_alloc(ar_ptr, nb); | |
2543 | (void)mutex_unlock(&ar_ptr->mutex); | |
7799b7b3 UD |
2544 | if(!victim) { |
2545 | /* Maybe the failure is due to running out of mmapped areas. */ | |
2546 | if(ar_ptr != &main_arena) { | |
2547 | (void)mutex_lock(&main_arena.mutex); | |
2548 | victim = chunk_alloc(&main_arena, nb); | |
2549 | (void)mutex_unlock(&main_arena.mutex); | |
2550 | } | |
2551 | if(!victim) return 0; | |
2552 | } | |
2553 | return chunk2mem(victim); | |
f65fd747 UD |
2554 | } |
2555 | ||
2556 | static mchunkptr | |
dfd2257a | 2557 | internal_function |
f65fd747 UD |
2558 | #if __STD_C |
2559 | chunk_alloc(arena *ar_ptr, INTERNAL_SIZE_T nb) | |
2560 | #else | |
2561 | chunk_alloc(ar_ptr, nb) arena *ar_ptr; INTERNAL_SIZE_T nb; | |
2562 | #endif | |
2563 | { | |
2564 | mchunkptr victim; /* inspected/selected chunk */ | |
2565 | INTERNAL_SIZE_T victim_size; /* its size */ | |
2566 | int idx; /* index for bin traversal */ | |
2567 | mbinptr bin; /* associated bin */ | |
2568 | mchunkptr remainder; /* remainder from a split */ | |
2569 | long remainder_size; /* its size */ | |
2570 | int remainder_index; /* its bin index */ | |
2571 | unsigned long block; /* block traverser bit */ | |
2572 | int startidx; /* first bin of a traversed block */ | |
2573 | mchunkptr fwd; /* misc temp for linking */ | |
2574 | mchunkptr bck; /* misc temp for linking */ | |
2575 | mbinptr q; /* misc temp */ | |
2576 | ||
2577 | ||
2578 | /* Check for exact match in a bin */ | |
2579 | ||
2580 | if (is_small_request(nb)) /* Faster version for small requests */ | |
2581 | { | |
2582 | idx = smallbin_index(nb); | |
2583 | ||
2584 | /* No traversal or size check necessary for small bins. */ | |
2585 | ||
2586 | q = bin_at(ar_ptr, idx); | |
2587 | victim = last(q); | |
2588 | ||
2589 | /* Also scan the next one, since it would have a remainder < MINSIZE */ | |
2590 | if (victim == q) | |
2591 | { | |
2592 | q = next_bin(q); | |
2593 | victim = last(q); | |
2594 | } | |
2595 | if (victim != q) | |
2596 | { | |
2597 | victim_size = chunksize(victim); | |
2598 | unlink(victim, bck, fwd); | |
2599 | set_inuse_bit_at_offset(victim, victim_size); | |
2600 | check_malloced_chunk(ar_ptr, victim, nb); | |
2601 | return victim; | |
2602 | } | |
2603 | ||
2604 | idx += 2; /* Set for bin scan below. We've already scanned 2 bins. */ | |
2605 | ||
2606 | } | |
2607 | else | |
2608 | { | |
2609 | idx = bin_index(nb); | |
2610 | bin = bin_at(ar_ptr, idx); | |
2611 | ||
2612 | for (victim = last(bin); victim != bin; victim = victim->bk) | |
2613 | { | |
2614 | victim_size = chunksize(victim); | |
2615 | remainder_size = victim_size - nb; | |
2616 | ||
2617 | if (remainder_size >= (long)MINSIZE) /* too big */ | |
2618 | { | |
2619 | --idx; /* adjust to rescan below after checking last remainder */ | |
2620 | break; | |
2621 | } | |
2622 | ||
2623 | else if (remainder_size >= 0) /* exact fit */ | |
2624 | { | |
2625 | unlink(victim, bck, fwd); | |
2626 | set_inuse_bit_at_offset(victim, victim_size); | |
2627 | check_malloced_chunk(ar_ptr, victim, nb); | |
2628 | return victim; | |
2629 | } | |
2630 | } | |
2631 | ||
2632 | ++idx; | |
2633 | ||
2634 | } | |
2635 | ||
2636 | /* Try to use the last split-off remainder */ | |
2637 | ||
2638 | if ( (victim = last_remainder(ar_ptr)->fd) != last_remainder(ar_ptr)) | |
2639 | { | |
2640 | victim_size = chunksize(victim); | |
2641 | remainder_size = victim_size - nb; | |
2642 | ||
2643 | if (remainder_size >= (long)MINSIZE) /* re-split */ | |
2644 | { | |
2645 | remainder = chunk_at_offset(victim, nb); | |
2646 | set_head(victim, nb | PREV_INUSE); | |
2647 | link_last_remainder(ar_ptr, remainder); | |
2648 | set_head(remainder, remainder_size | PREV_INUSE); | |
2649 | set_foot(remainder, remainder_size); | |
2650 | check_malloced_chunk(ar_ptr, victim, nb); | |
2651 | return victim; | |
2652 | } | |
2653 | ||
2654 | clear_last_remainder(ar_ptr); | |
2655 | ||
2656 | if (remainder_size >= 0) /* exhaust */ | |
2657 | { | |
2658 | set_inuse_bit_at_offset(victim, victim_size); | |
2659 | check_malloced_chunk(ar_ptr, victim, nb); | |
2660 | return victim; | |
2661 | } | |
2662 | ||
2663 | /* Else place in bin */ | |
2664 | ||
2665 | frontlink(ar_ptr, victim, victim_size, remainder_index, bck, fwd); | |
2666 | } | |
2667 | ||
2668 | /* | |
2669 | If there are any possibly nonempty big-enough blocks, | |
2670 | search for best fitting chunk by scanning bins in blockwidth units. | |
2671 | */ | |
2672 | ||
2673 | if ( (block = idx2binblock(idx)) <= binblocks(ar_ptr)) | |
2674 | { | |
2675 | ||
2676 | /* Get to the first marked block */ | |
2677 | ||
2678 | if ( (block & binblocks(ar_ptr)) == 0) | |
2679 | { | |
2680 | /* force to an even block boundary */ | |
2681 | idx = (idx & ~(BINBLOCKWIDTH - 1)) + BINBLOCKWIDTH; | |
2682 | block <<= 1; | |
2683 | while ((block & binblocks(ar_ptr)) == 0) | |
2684 | { | |
2685 | idx += BINBLOCKWIDTH; | |
2686 | block <<= 1; | |
2687 | } | |
2688 | } | |
2689 | ||
2690 | /* For each possibly nonempty block ... */ | |
2691 | for (;;) | |
2692 | { | |
2693 | startidx = idx; /* (track incomplete blocks) */ | |
2694 | q = bin = bin_at(ar_ptr, idx); | |
2695 | ||
2696 | /* For each bin in this block ... */ | |
2697 | do | |
2698 | { | |
2699 | /* Find and use first big enough chunk ... */ | |
2700 | ||
2701 | for (victim = last(bin); victim != bin; victim = victim->bk) | |
2702 | { | |
2703 | victim_size = chunksize(victim); | |
2704 | remainder_size = victim_size - nb; | |
2705 | ||
2706 | if (remainder_size >= (long)MINSIZE) /* split */ | |
2707 | { | |
2708 | remainder = chunk_at_offset(victim, nb); | |
2709 | set_head(victim, nb | PREV_INUSE); | |
2710 | unlink(victim, bck, fwd); | |
2711 | link_last_remainder(ar_ptr, remainder); | |
2712 | set_head(remainder, remainder_size | PREV_INUSE); | |
2713 | set_foot(remainder, remainder_size); | |
2714 | check_malloced_chunk(ar_ptr, victim, nb); | |
2715 | return victim; | |
2716 | } | |
2717 | ||
2718 | else if (remainder_size >= 0) /* take */ | |
2719 | { | |
2720 | set_inuse_bit_at_offset(victim, victim_size); | |
2721 | unlink(victim, bck, fwd); | |
2722 | check_malloced_chunk(ar_ptr, victim, nb); | |
2723 | return victim; | |
2724 | } | |
2725 | ||
2726 | } | |
2727 | ||
2728 | bin = next_bin(bin); | |
2729 | ||
2730 | } while ((++idx & (BINBLOCKWIDTH - 1)) != 0); | |
2731 | ||
2732 | /* Clear out the block bit. */ | |
2733 | ||
2734 | do /* Possibly backtrack to try to clear a partial block */ | |
2735 | { | |
2736 | if ((startidx & (BINBLOCKWIDTH - 1)) == 0) | |
2737 | { | |
2738 | binblocks(ar_ptr) &= ~block; | |
2739 | break; | |
2740 | } | |
2741 | --startidx; | |
2742 | q = prev_bin(q); | |
2743 | } while (first(q) == q); | |
2744 | ||
2745 | /* Get to the next possibly nonempty block */ | |
2746 | ||
2747 | if ( (block <<= 1) <= binblocks(ar_ptr) && (block != 0) ) | |
2748 | { | |
2749 | while ((block & binblocks(ar_ptr)) == 0) | |
2750 | { | |
2751 | idx += BINBLOCKWIDTH; | |
2752 | block <<= 1; | |
2753 | } | |
2754 | } | |
2755 | else | |
2756 | break; | |
2757 | } | |
2758 | } | |
2759 | ||
2760 | ||
2761 | /* Try to use top chunk */ | |
2762 | ||
2763 | /* Require that there be a remainder, ensuring top always exists */ | |
2764 | if ( (remainder_size = chunksize(top(ar_ptr)) - nb) < (long)MINSIZE) | |
2765 | { | |
2766 | ||
2767 | #if HAVE_MMAP | |
2768 | /* If big and would otherwise need to extend, try to use mmap instead */ | |
2769 | if ((unsigned long)nb >= (unsigned long)mmap_threshold && | |
2770 | (victim = mmap_chunk(nb)) != 0) | |
2771 | return victim; | |
2772 | #endif | |
2773 | ||
2774 | /* Try to extend */ | |
2775 | malloc_extend_top(ar_ptr, nb); | |
2776 | if ((remainder_size = chunksize(top(ar_ptr)) - nb) < (long)MINSIZE) | |
2777 | return 0; /* propagate failure */ | |
2778 | } | |
2779 | ||
2780 | victim = top(ar_ptr); | |
2781 | set_head(victim, nb | PREV_INUSE); | |
2782 | top(ar_ptr) = chunk_at_offset(victim, nb); | |
2783 | set_head(top(ar_ptr), remainder_size | PREV_INUSE); | |
2784 | check_malloced_chunk(ar_ptr, victim, nb); | |
2785 | return victim; | |
2786 | ||
2787 | } | |
2788 | ||
2789 | ||
2790 | \f | |
2791 | ||
2792 | /* | |
2793 | ||
2794 | free() algorithm : | |
2795 | ||
2796 | cases: | |
2797 | ||
2798 | 1. free(0) has no effect. | |
2799 | ||
2800 | 2. If the chunk was allocated via mmap, it is released via munmap(). | |
2801 | ||
2802 | 3. If a returned chunk borders the current high end of memory, | |
2803 | it is consolidated into the top, and if the total unused | |
2804 | topmost memory exceeds the trim threshold, malloc_trim is | |
2805 | called. | |
2806 | ||
2807 | 4. Other chunks are consolidated as they arrive, and | |
2808 | placed in corresponding bins. (This includes the case of | |
2809 | consolidating with the current `last_remainder'). | |
2810 | ||
2811 | */ | |
2812 | ||
2813 | ||
2814 | #if __STD_C | |
2815 | void fREe(Void_t* mem) | |
2816 | #else | |
2817 | void fREe(mem) Void_t* mem; | |
2818 | #endif | |
2819 | { | |
2820 | arena *ar_ptr; | |
2821 | mchunkptr p; /* chunk corresponding to mem */ | |
2822 | ||
dfd2257a | 2823 | #if defined _LIBC || defined MALLOC_HOOKS |
10dc2a90 | 2824 | if (__free_hook != NULL) { |
dfd2257a | 2825 | #if defined __GNUC__ && __GNUC__ >= 2 |
a2b08ee5 UD |
2826 | (*__free_hook)(mem, __builtin_return_address (0)); |
2827 | #else | |
dfd2257a | 2828 | (*__free_hook)(mem, NULL); |
a2b08ee5 | 2829 | #endif |
10dc2a90 UD |
2830 | return; |
2831 | } | |
2832 | #endif | |
2833 | ||
f65fd747 UD |
2834 | if (mem == 0) /* free(0) has no effect */ |
2835 | return; | |
2836 | ||
2837 | p = mem2chunk(mem); | |
2838 | ||
2839 | #if HAVE_MMAP | |
2840 | if (chunk_is_mmapped(p)) /* release mmapped memory. */ | |
2841 | { | |
2842 | munmap_chunk(p); | |
2843 | return; | |
2844 | } | |
2845 | #endif | |
2846 | ||
2847 | ar_ptr = arena_for_ptr(p); | |
8a4b65b4 UD |
2848 | #if THREAD_STATS |
2849 | if(!mutex_trylock(&ar_ptr->mutex)) | |
2850 | ++(ar_ptr->stat_lock_direct); | |
2851 | else { | |
2852 | (void)mutex_lock(&ar_ptr->mutex); | |
2853 | ++(ar_ptr->stat_lock_wait); | |
2854 | } | |
2855 | #else | |
f65fd747 | 2856 | (void)mutex_lock(&ar_ptr->mutex); |
8a4b65b4 | 2857 | #endif |
f65fd747 UD |
2858 | chunk_free(ar_ptr, p); |
2859 | (void)mutex_unlock(&ar_ptr->mutex); | |
2860 | } | |
2861 | ||
2862 | static void | |
dfd2257a | 2863 | internal_function |
f65fd747 UD |
2864 | #if __STD_C |
2865 | chunk_free(arena *ar_ptr, mchunkptr p) | |
2866 | #else | |
2867 | chunk_free(ar_ptr, p) arena *ar_ptr; mchunkptr p; | |
2868 | #endif | |
2869 | { | |
2870 | INTERNAL_SIZE_T hd = p->size; /* its head field */ | |
2871 | INTERNAL_SIZE_T sz; /* its size */ | |
2872 | int idx; /* its bin index */ | |
2873 | mchunkptr next; /* next contiguous chunk */ | |
2874 | INTERNAL_SIZE_T nextsz; /* its size */ | |
2875 | INTERNAL_SIZE_T prevsz; /* size of previous contiguous chunk */ | |
2876 | mchunkptr bck; /* misc temp for linking */ | |
2877 | mchunkptr fwd; /* misc temp for linking */ | |
2878 | int islr; /* track whether merging with last_remainder */ | |
2879 | ||
2880 | check_inuse_chunk(ar_ptr, p); | |
2881 | ||
2882 | sz = hd & ~PREV_INUSE; | |
2883 | next = chunk_at_offset(p, sz); | |
2884 | nextsz = chunksize(next); | |
2885 | ||
2886 | if (next == top(ar_ptr)) /* merge with top */ | |
2887 | { | |
2888 | sz += nextsz; | |
2889 | ||
2890 | if (!(hd & PREV_INUSE)) /* consolidate backward */ | |
2891 | { | |
2892 | prevsz = p->prev_size; | |
2893 | p = chunk_at_offset(p, -prevsz); | |
2894 | sz += prevsz; | |
2895 | unlink(p, bck, fwd); | |
2896 | } | |
2897 | ||
2898 | set_head(p, sz | PREV_INUSE); | |
2899 | top(ar_ptr) = p; | |
8a4b65b4 UD |
2900 | |
2901 | #ifndef NO_THREADS | |
2902 | if(ar_ptr == &main_arena) { | |
2903 | #endif | |
2904 | if ((unsigned long)(sz) >= (unsigned long)trim_threshold) | |
2905 | main_trim(top_pad); | |
2906 | #ifndef NO_THREADS | |
2907 | } else { | |
2908 | heap_info *heap = heap_for_ptr(p); | |
2909 | ||
2910 | assert(heap->ar_ptr == ar_ptr); | |
2911 | ||
2912 | /* Try to get rid of completely empty heaps, if possible. */ | |
2913 | if((unsigned long)(sz) >= (unsigned long)trim_threshold || | |
2914 | p == chunk_at_offset(heap, sizeof(*heap))) | |
2915 | heap_trim(heap, top_pad); | |
2916 | } | |
2917 | #endif | |
f65fd747 UD |
2918 | return; |
2919 | } | |
2920 | ||
f65fd747 UD |
2921 | islr = 0; |
2922 | ||
2923 | if (!(hd & PREV_INUSE)) /* consolidate backward */ | |
2924 | { | |
2925 | prevsz = p->prev_size; | |
2926 | p = chunk_at_offset(p, -prevsz); | |
2927 | sz += prevsz; | |
2928 | ||
2929 | if (p->fd == last_remainder(ar_ptr)) /* keep as last_remainder */ | |
2930 | islr = 1; | |
2931 | else | |
2932 | unlink(p, bck, fwd); | |
2933 | } | |
2934 | ||
2935 | if (!(inuse_bit_at_offset(next, nextsz))) /* consolidate forward */ | |
2936 | { | |
2937 | sz += nextsz; | |
2938 | ||
2939 | if (!islr && next->fd == last_remainder(ar_ptr)) | |
2940 | /* re-insert last_remainder */ | |
2941 | { | |
2942 | islr = 1; | |
2943 | link_last_remainder(ar_ptr, p); | |
2944 | } | |
2945 | else | |
2946 | unlink(next, bck, fwd); | |
7799b7b3 UD |
2947 | |
2948 | next = chunk_at_offset(p, sz); | |
f65fd747 | 2949 | } |
7799b7b3 UD |
2950 | else |
2951 | set_head(next, nextsz); /* clear inuse bit */ | |
f65fd747 UD |
2952 | |
2953 | set_head(p, sz | PREV_INUSE); | |
7799b7b3 | 2954 | next->prev_size = sz; |
f65fd747 UD |
2955 | if (!islr) |
2956 | frontlink(ar_ptr, p, sz, idx, bck, fwd); | |
7799b7b3 UD |
2957 | |
2958 | #ifndef NO_THREADS | |
2959 | /* Check whether the heap containing top can go away now. */ | |
2960 | if(next->size < MINSIZE && | |
2961 | (unsigned long)sz > trim_threshold && | |
2962 | ar_ptr != &main_arena) { /* fencepost */ | |
2963 | heap_info* heap = heap_for_ptr(top(ar_ptr)); | |
2964 | ||
2965 | if(top(ar_ptr) == chunk_at_offset(heap, sizeof(*heap)) && | |
2966 | heap->prev == heap_for_ptr(p)) | |
2967 | heap_trim(heap, top_pad); | |
2968 | } | |
2969 | #endif | |
f65fd747 UD |
2970 | } |
2971 | ||
2972 | ||
2973 | \f | |
2974 | ||
2975 | ||
2976 | /* | |
2977 | ||
2978 | Realloc algorithm: | |
2979 | ||
2980 | Chunks that were obtained via mmap cannot be extended or shrunk | |
2981 | unless HAVE_MREMAP is defined, in which case mremap is used. | |
2982 | Otherwise, if their reallocation is for additional space, they are | |
2983 | copied. If for less, they are just left alone. | |
2984 | ||
2985 | Otherwise, if the reallocation is for additional space, and the | |
2986 | chunk can be extended, it is, else a malloc-copy-free sequence is | |
2987 | taken. There are several different ways that a chunk could be | |
2988 | extended. All are tried: | |
2989 | ||
2990 | * Extending forward into following adjacent free chunk. | |
2991 | * Shifting backwards, joining preceding adjacent space | |
2992 | * Both shifting backwards and extending forward. | |
2993 | * Extending into newly sbrked space | |
2994 | ||
2995 | Unless the #define REALLOC_ZERO_BYTES_FREES is set, realloc with a | |
2996 | size argument of zero (re)allocates a minimum-sized chunk. | |
2997 | ||
2998 | If the reallocation is for less space, and the new request is for | |
2999 | a `small' (<512 bytes) size, then the newly unused space is lopped | |
3000 | off and freed. | |
3001 | ||
3002 | The old unix realloc convention of allowing the last-free'd chunk | |
3003 | to be used as an argument to realloc is no longer supported. | |
3004 | I don't know of any programs still relying on this feature, | |
3005 | and allowing it would also allow too many other incorrect | |
3006 | usages of realloc to be sensible. | |
3007 | ||
3008 | ||
3009 | */ | |
3010 | ||
3011 | ||
3012 | #if __STD_C | |
3013 | Void_t* rEALLOc(Void_t* oldmem, size_t bytes) | |
3014 | #else | |
3015 | Void_t* rEALLOc(oldmem, bytes) Void_t* oldmem; size_t bytes; | |
3016 | #endif | |
3017 | { | |
3018 | arena *ar_ptr; | |
3019 | INTERNAL_SIZE_T nb; /* padded request size */ | |
3020 | ||
3021 | mchunkptr oldp; /* chunk corresponding to oldmem */ | |
3022 | INTERNAL_SIZE_T oldsize; /* its size */ | |
3023 | ||
3024 | mchunkptr newp; /* chunk to return */ | |
f65fd747 | 3025 | |
dfd2257a | 3026 | #if defined _LIBC || defined MALLOC_HOOKS |
10dc2a90 UD |
3027 | if (__realloc_hook != NULL) { |
3028 | Void_t* result; | |
f65fd747 | 3029 | |
dfd2257a | 3030 | #if defined __GNUC__ && __GNUC__ >= 2 |
a2b08ee5 UD |
3031 | result = (*__realloc_hook)(oldmem, bytes, __builtin_return_address (0)); |
3032 | #else | |
dfd2257a | 3033 | result = (*__realloc_hook)(oldmem, bytes, NULL); |
a2b08ee5 | 3034 | #endif |
10dc2a90 UD |
3035 | return result; |
3036 | } | |
3037 | #endif | |
f65fd747 UD |
3038 | |
3039 | #ifdef REALLOC_ZERO_BYTES_FREES | |
3040 | if (bytes == 0) { fREe(oldmem); return 0; } | |
3041 | #endif | |
3042 | ||
f65fd747 UD |
3043 | /* realloc of null is supposed to be same as malloc */ |
3044 | if (oldmem == 0) return mALLOc(bytes); | |
3045 | ||
10dc2a90 UD |
3046 | oldp = mem2chunk(oldmem); |
3047 | oldsize = chunksize(oldp); | |
f65fd747 UD |
3048 | |
3049 | nb = request2size(bytes); | |
3050 | ||
3051 | #if HAVE_MMAP | |
3052 | if (chunk_is_mmapped(oldp)) | |
3053 | { | |
10dc2a90 UD |
3054 | Void_t* newmem; |
3055 | ||
f65fd747 UD |
3056 | #if HAVE_MREMAP |
3057 | newp = mremap_chunk(oldp, nb); | |
3058 | if(newp) return chunk2mem(newp); | |
3059 | #endif | |
3060 | /* Note the extra SIZE_SZ overhead. */ | |
3061 | if(oldsize - SIZE_SZ >= nb) return oldmem; /* do nothing */ | |
3062 | /* Must alloc, copy, free. */ | |
3063 | newmem = mALLOc(bytes); | |
3064 | if (newmem == 0) return 0; /* propagate failure */ | |
3065 | MALLOC_COPY(newmem, oldmem, oldsize - 2*SIZE_SZ); | |
3066 | munmap_chunk(oldp); | |
3067 | return newmem; | |
3068 | } | |
3069 | #endif | |
3070 | ||
3071 | ar_ptr = arena_for_ptr(oldp); | |
8a4b65b4 UD |
3072 | #if THREAD_STATS |
3073 | if(!mutex_trylock(&ar_ptr->mutex)) | |
3074 | ++(ar_ptr->stat_lock_direct); | |
3075 | else { | |
3076 | (void)mutex_lock(&ar_ptr->mutex); | |
3077 | ++(ar_ptr->stat_lock_wait); | |
3078 | } | |
3079 | #else | |
f65fd747 | 3080 | (void)mutex_lock(&ar_ptr->mutex); |
8a4b65b4 UD |
3081 | #endif |
3082 | ||
1228ed5c | 3083 | #ifndef NO_THREADS |
f65fd747 UD |
3084 | /* As in malloc(), remember this arena for the next allocation. */ |
3085 | tsd_setspecific(arena_key, (Void_t *)ar_ptr); | |
1228ed5c | 3086 | #endif |
f65fd747 | 3087 | |
10dc2a90 UD |
3088 | newp = chunk_realloc(ar_ptr, oldp, oldsize, nb); |
3089 | ||
3090 | (void)mutex_unlock(&ar_ptr->mutex); | |
3091 | return newp ? chunk2mem(newp) : NULL; | |
3092 | } | |
3093 | ||
3094 | static mchunkptr | |
dfd2257a | 3095 | internal_function |
10dc2a90 UD |
3096 | #if __STD_C |
3097 | chunk_realloc(arena* ar_ptr, mchunkptr oldp, INTERNAL_SIZE_T oldsize, | |
7e3be507 | 3098 | INTERNAL_SIZE_T nb) |
10dc2a90 UD |
3099 | #else |
3100 | chunk_realloc(ar_ptr, oldp, oldsize, nb) | |
3101 | arena* ar_ptr; mchunkptr oldp; INTERNAL_SIZE_T oldsize, nb; | |
3102 | #endif | |
3103 | { | |
3104 | mchunkptr newp = oldp; /* chunk to return */ | |
3105 | INTERNAL_SIZE_T newsize = oldsize; /* its size */ | |
3106 | ||
3107 | mchunkptr next; /* next contiguous chunk after oldp */ | |
3108 | INTERNAL_SIZE_T nextsize; /* its size */ | |
3109 | ||
3110 | mchunkptr prev; /* previous contiguous chunk before oldp */ | |
3111 | INTERNAL_SIZE_T prevsize; /* its size */ | |
3112 | ||
3113 | mchunkptr remainder; /* holds split off extra space from newp */ | |
3114 | INTERNAL_SIZE_T remainder_size; /* its size */ | |
3115 | ||
3116 | mchunkptr bck; /* misc temp for linking */ | |
3117 | mchunkptr fwd; /* misc temp for linking */ | |
3118 | ||
f65fd747 UD |
3119 | check_inuse_chunk(ar_ptr, oldp); |
3120 | ||
3121 | if ((long)(oldsize) < (long)(nb)) | |
3122 | { | |
3123 | ||
3124 | /* Try expanding forward */ | |
3125 | ||
3126 | next = chunk_at_offset(oldp, oldsize); | |
3127 | if (next == top(ar_ptr) || !inuse(next)) | |
3128 | { | |
3129 | nextsize = chunksize(next); | |
3130 | ||
3131 | /* Forward into top only if a remainder */ | |
3132 | if (next == top(ar_ptr)) | |
3133 | { | |
3134 | if ((long)(nextsize + newsize) >= (long)(nb + MINSIZE)) | |
3135 | { | |
3136 | newsize += nextsize; | |
3137 | top(ar_ptr) = chunk_at_offset(oldp, nb); | |
3138 | set_head(top(ar_ptr), (newsize - nb) | PREV_INUSE); | |
3139 | set_head_size(oldp, nb); | |
10dc2a90 | 3140 | return oldp; |
f65fd747 UD |
3141 | } |
3142 | } | |
3143 | ||
3144 | /* Forward into next chunk */ | |
3145 | else if (((long)(nextsize + newsize) >= (long)(nb))) | |
3146 | { | |
3147 | unlink(next, bck, fwd); | |
3148 | newsize += nextsize; | |
3149 | goto split; | |
3150 | } | |
3151 | } | |
3152 | else | |
3153 | { | |
3154 | next = 0; | |
3155 | nextsize = 0; | |
3156 | } | |
3157 | ||
3158 | /* Try shifting backwards. */ | |
3159 | ||
3160 | if (!prev_inuse(oldp)) | |
3161 | { | |
3162 | prev = prev_chunk(oldp); | |
3163 | prevsize = chunksize(prev); | |
3164 | ||
3165 | /* try forward + backward first to save a later consolidation */ | |
3166 | ||
3167 | if (next != 0) | |
3168 | { | |
3169 | /* into top */ | |
3170 | if (next == top(ar_ptr)) | |
3171 | { | |
3172 | if ((long)(nextsize + prevsize + newsize) >= (long)(nb + MINSIZE)) | |
3173 | { | |
3174 | unlink(prev, bck, fwd); | |
3175 | newp = prev; | |
3176 | newsize += prevsize + nextsize; | |
10dc2a90 | 3177 | MALLOC_COPY(chunk2mem(newp), chunk2mem(oldp), oldsize - SIZE_SZ); |
f65fd747 UD |
3178 | top(ar_ptr) = chunk_at_offset(newp, nb); |
3179 | set_head(top(ar_ptr), (newsize - nb) | PREV_INUSE); | |
3180 | set_head_size(newp, nb); | |
10dc2a90 | 3181 | return newp; |
f65fd747 UD |
3182 | } |
3183 | } | |
3184 | ||
3185 | /* into next chunk */ | |
3186 | else if (((long)(nextsize + prevsize + newsize) >= (long)(nb))) | |
3187 | { | |
3188 | unlink(next, bck, fwd); | |
3189 | unlink(prev, bck, fwd); | |
3190 | newp = prev; | |
3191 | newsize += nextsize + prevsize; | |
10dc2a90 | 3192 | MALLOC_COPY(chunk2mem(newp), chunk2mem(oldp), oldsize - SIZE_SZ); |
f65fd747 UD |
3193 | goto split; |
3194 | } | |
3195 | } | |
3196 | ||
3197 | /* backward only */ | |
3198 | if (prev != 0 && (long)(prevsize + newsize) >= (long)nb) | |
3199 | { | |
3200 | unlink(prev, bck, fwd); | |
3201 | newp = prev; | |
3202 | newsize += prevsize; | |
10dc2a90 | 3203 | MALLOC_COPY(chunk2mem(newp), chunk2mem(oldp), oldsize - SIZE_SZ); |
f65fd747 UD |
3204 | goto split; |
3205 | } | |
3206 | } | |
3207 | ||
3208 | /* Must allocate */ | |
3209 | ||
3210 | newp = chunk_alloc (ar_ptr, nb); | |
3211 | ||
7799b7b3 UD |
3212 | if (newp == 0) { |
3213 | /* Maybe the failure is due to running out of mmapped areas. */ | |
3214 | if (ar_ptr != &main_arena) { | |
3215 | (void)mutex_lock(&main_arena.mutex); | |
3216 | newp = chunk_alloc(&main_arena, nb); | |
3217 | (void)mutex_unlock(&main_arena.mutex); | |
3218 | } | |
3219 | if (newp == 0) /* propagate failure */ | |
3220 | return 0; | |
3221 | } | |
f65fd747 UD |
3222 | |
3223 | /* Avoid copy if newp is next chunk after oldp. */ | |
3224 | /* (This can only happen when new chunk is sbrk'ed.) */ | |
3225 | ||
3226 | if ( newp == next_chunk(oldp)) | |
3227 | { | |
3228 | newsize += chunksize(newp); | |
3229 | newp = oldp; | |
3230 | goto split; | |
3231 | } | |
3232 | ||
3233 | /* Otherwise copy, free, and exit */ | |
10dc2a90 | 3234 | MALLOC_COPY(chunk2mem(newp), chunk2mem(oldp), oldsize - SIZE_SZ); |
f65fd747 | 3235 | chunk_free(ar_ptr, oldp); |
10dc2a90 | 3236 | return newp; |
f65fd747 UD |
3237 | } |
3238 | ||
3239 | ||
3240 | split: /* split off extra room in old or expanded chunk */ | |
3241 | ||
3242 | if (newsize - nb >= MINSIZE) /* split off remainder */ | |
3243 | { | |
3244 | remainder = chunk_at_offset(newp, nb); | |
3245 | remainder_size = newsize - nb; | |
3246 | set_head_size(newp, nb); | |
3247 | set_head(remainder, remainder_size | PREV_INUSE); | |
3248 | set_inuse_bit_at_offset(remainder, remainder_size); | |
3249 | chunk_free(ar_ptr, remainder); | |
3250 | } | |
3251 | else | |
3252 | { | |
3253 | set_head_size(newp, newsize); | |
3254 | set_inuse_bit_at_offset(newp, newsize); | |
3255 | } | |
3256 | ||
3257 | check_inuse_chunk(ar_ptr, newp); | |
10dc2a90 | 3258 | return newp; |
f65fd747 UD |
3259 | } |
3260 | ||
3261 | ||
3262 | \f | |
3263 | ||
3264 | /* | |
3265 | ||
3266 | memalign algorithm: | |
3267 | ||
3268 | memalign requests more than enough space from malloc, finds a spot | |
3269 | within that chunk that meets the alignment request, and then | |
3270 | possibly frees the leading and trailing space. | |
3271 | ||
3272 | The alignment argument must be a power of two. This property is not | |
3273 | checked by memalign, so misuse may result in random runtime errors. | |
3274 | ||
3275 | 8-byte alignment is guaranteed by normal malloc calls, so don't | |
3276 | bother calling memalign with an argument of 8 or less. | |
3277 | ||
3278 | Overreliance on memalign is a sure way to fragment space. | |
3279 | ||
3280 | */ | |
3281 | ||
3282 | ||
3283 | #if __STD_C | |
3284 | Void_t* mEMALIGn(size_t alignment, size_t bytes) | |
3285 | #else | |
3286 | Void_t* mEMALIGn(alignment, bytes) size_t alignment; size_t bytes; | |
3287 | #endif | |
3288 | { | |
3289 | arena *ar_ptr; | |
3290 | INTERNAL_SIZE_T nb; /* padded request size */ | |
10dc2a90 UD |
3291 | mchunkptr p; |
3292 | ||
dfd2257a | 3293 | #if defined _LIBC || defined MALLOC_HOOKS |
10dc2a90 UD |
3294 | if (__memalign_hook != NULL) { |
3295 | Void_t* result; | |
3296 | ||
dfd2257a | 3297 | #if defined __GNUC__ && __GNUC__ >= 2 |
a2b08ee5 UD |
3298 | result = (*__memalign_hook)(alignment, bytes, |
3299 | __builtin_return_address (0)); | |
3300 | #else | |
dfd2257a | 3301 | result = (*__memalign_hook)(alignment, bytes, NULL); |
a2b08ee5 | 3302 | #endif |
10dc2a90 UD |
3303 | return result; |
3304 | } | |
3305 | #endif | |
f65fd747 UD |
3306 | |
3307 | /* If need less alignment than we give anyway, just relay to malloc */ | |
3308 | ||
3309 | if (alignment <= MALLOC_ALIGNMENT) return mALLOc(bytes); | |
3310 | ||
3311 | /* Otherwise, ensure that it is at least a minimum chunk size */ | |
3312 | ||
3313 | if (alignment < MINSIZE) alignment = MINSIZE; | |
3314 | ||
f65fd747 UD |
3315 | nb = request2size(bytes); |
3316 | arena_get(ar_ptr, nb + alignment + MINSIZE); | |
3317 | if(!ar_ptr) | |
3318 | return 0; | |
10dc2a90 UD |
3319 | p = chunk_align(ar_ptr, nb, alignment); |
3320 | (void)mutex_unlock(&ar_ptr->mutex); | |
7799b7b3 UD |
3321 | if(!p) { |
3322 | /* Maybe the failure is due to running out of mmapped areas. */ | |
3323 | if(ar_ptr != &main_arena) { | |
3324 | (void)mutex_lock(&main_arena.mutex); | |
3325 | p = chunk_align(&main_arena, nb, alignment); | |
3326 | (void)mutex_unlock(&main_arena.mutex); | |
3327 | } | |
3328 | if(!p) return 0; | |
3329 | } | |
3330 | return chunk2mem(p); | |
10dc2a90 | 3331 | } |
f65fd747 | 3332 | |
10dc2a90 | 3333 | static mchunkptr |
dfd2257a | 3334 | internal_function |
10dc2a90 UD |
3335 | #if __STD_C |
3336 | chunk_align(arena* ar_ptr, INTERNAL_SIZE_T nb, size_t alignment) | |
3337 | #else | |
3338 | chunk_align(ar_ptr, nb, alignment) | |
3339 | arena* ar_ptr; INTERNAL_SIZE_T nb; size_t alignment; | |
3340 | #endif | |
3341 | { | |
3342 | char* m; /* memory returned by malloc call */ | |
3343 | mchunkptr p; /* corresponding chunk */ | |
3344 | char* brk; /* alignment point within p */ | |
3345 | mchunkptr newp; /* chunk to return */ | |
3346 | INTERNAL_SIZE_T newsize; /* its size */ | |
3347 | INTERNAL_SIZE_T leadsize; /* leading space befor alignment point */ | |
3348 | mchunkptr remainder; /* spare room at end to split off */ | |
3349 | long remainder_size; /* its size */ | |
3350 | ||
3351 | /* Call chunk_alloc with worst case padding to hit alignment. */ | |
3352 | p = chunk_alloc(ar_ptr, nb + alignment + MINSIZE); | |
3353 | if (p == 0) | |
f65fd747 | 3354 | return 0; /* propagate failure */ |
f65fd747 UD |
3355 | |
3356 | m = chunk2mem(p); | |
3357 | ||
3358 | if ((((unsigned long)(m)) % alignment) == 0) /* aligned */ | |
3359 | { | |
3360 | #if HAVE_MMAP | |
3361 | if(chunk_is_mmapped(p)) { | |
10dc2a90 | 3362 | return p; /* nothing more to do */ |
f65fd747 UD |
3363 | } |
3364 | #endif | |
3365 | } | |
3366 | else /* misaligned */ | |
3367 | { | |
3368 | /* | |
3369 | Find an aligned spot inside chunk. | |
3370 | Since we need to give back leading space in a chunk of at | |
3371 | least MINSIZE, if the first calculation places us at | |
3372 | a spot with less than MINSIZE leader, we can move to the | |
3373 | next aligned spot -- we've allocated enough total room so that | |
3374 | this is always possible. | |
3375 | */ | |
3376 | ||
3377 | brk = (char*)mem2chunk(((unsigned long)(m + alignment - 1)) & -alignment); | |
10dc2a90 | 3378 | if ((long)(brk - (char*)(p)) < (long)MINSIZE) brk += alignment; |
f65fd747 UD |
3379 | |
3380 | newp = (mchunkptr)brk; | |
3381 | leadsize = brk - (char*)(p); | |
3382 | newsize = chunksize(p) - leadsize; | |
3383 | ||
3384 | #if HAVE_MMAP | |
3385 | if(chunk_is_mmapped(p)) | |
3386 | { | |
3387 | newp->prev_size = p->prev_size + leadsize; | |
3388 | set_head(newp, newsize|IS_MMAPPED); | |
10dc2a90 | 3389 | return newp; |
f65fd747 UD |
3390 | } |
3391 | #endif | |
3392 | ||
3393 | /* give back leader, use the rest */ | |
3394 | ||
3395 | set_head(newp, newsize | PREV_INUSE); | |
3396 | set_inuse_bit_at_offset(newp, newsize); | |
3397 | set_head_size(p, leadsize); | |
3398 | chunk_free(ar_ptr, p); | |
3399 | p = newp; | |
3400 | ||
3401 | assert (newsize>=nb && (((unsigned long)(chunk2mem(p))) % alignment) == 0); | |
3402 | } | |
3403 | ||
3404 | /* Also give back spare room at the end */ | |
3405 | ||
3406 | remainder_size = chunksize(p) - nb; | |
3407 | ||
3408 | if (remainder_size >= (long)MINSIZE) | |
3409 | { | |
3410 | remainder = chunk_at_offset(p, nb); | |
3411 | set_head(remainder, remainder_size | PREV_INUSE); | |
3412 | set_head_size(p, nb); | |
3413 | chunk_free(ar_ptr, remainder); | |
3414 | } | |
3415 | ||
3416 | check_inuse_chunk(ar_ptr, p); | |
10dc2a90 | 3417 | return p; |
f65fd747 UD |
3418 | } |
3419 | ||
3420 | \f | |
3421 | ||
3422 | ||
3423 | /* | |
3424 | valloc just invokes memalign with alignment argument equal | |
3425 | to the page size of the system (or as near to this as can | |
3426 | be figured out from all the includes/defines above.) | |
3427 | */ | |
3428 | ||
3429 | #if __STD_C | |
3430 | Void_t* vALLOc(size_t bytes) | |
3431 | #else | |
3432 | Void_t* vALLOc(bytes) size_t bytes; | |
3433 | #endif | |
3434 | { | |
3435 | return mEMALIGn (malloc_getpagesize, bytes); | |
3436 | } | |
3437 | ||
3438 | /* | |
3439 | pvalloc just invokes valloc for the nearest pagesize | |
3440 | that will accommodate request | |
3441 | */ | |
3442 | ||
3443 | ||
3444 | #if __STD_C | |
3445 | Void_t* pvALLOc(size_t bytes) | |
3446 | #else | |
3447 | Void_t* pvALLOc(bytes) size_t bytes; | |
3448 | #endif | |
3449 | { | |
3450 | size_t pagesize = malloc_getpagesize; | |
3451 | return mEMALIGn (pagesize, (bytes + pagesize - 1) & ~(pagesize - 1)); | |
3452 | } | |
3453 | ||
3454 | /* | |
3455 | ||
10dc2a90 | 3456 | calloc calls chunk_alloc, then zeroes out the allocated chunk. |
f65fd747 UD |
3457 | |
3458 | */ | |
3459 | ||
3460 | #if __STD_C | |
3461 | Void_t* cALLOc(size_t n, size_t elem_size) | |
3462 | #else | |
3463 | Void_t* cALLOc(n, elem_size) size_t n; size_t elem_size; | |
3464 | #endif | |
3465 | { | |
3466 | arena *ar_ptr; | |
3467 | mchunkptr p, oldtop; | |
10dc2a90 | 3468 | INTERNAL_SIZE_T sz, csz, oldtopsize; |
f65fd747 UD |
3469 | Void_t* mem; |
3470 | ||
dfd2257a | 3471 | #if defined _LIBC || defined MALLOC_HOOKS |
10dc2a90 UD |
3472 | if (__malloc_hook != NULL) { |
3473 | sz = n * elem_size; | |
dfd2257a | 3474 | #if defined __GNUC__ && __GNUC__ >= 2 |
a2b08ee5 UD |
3475 | mem = (*__malloc_hook)(sz, __builtin_return_address (0)); |
3476 | #else | |
dfd2257a | 3477 | mem = (*__malloc_hook)(sz, NULL); |
a2b08ee5 | 3478 | #endif |
831372e7 UD |
3479 | if(mem == 0) |
3480 | return 0; | |
a2b08ee5 | 3481 | #ifdef HAVE_MEMSET |
c131718c | 3482 | return memset(mem, 0, sz); |
10dc2a90 | 3483 | #else |
831372e7 | 3484 | while(sz > 0) ((char*)mem)[--sz] = 0; /* rather inefficient */ |
10dc2a90 | 3485 | return mem; |
c131718c | 3486 | #endif |
10dc2a90 UD |
3487 | } |
3488 | #endif | |
f65fd747 | 3489 | |
10dc2a90 | 3490 | sz = request2size(n * elem_size); |
f65fd747 UD |
3491 | arena_get(ar_ptr, sz); |
3492 | if(!ar_ptr) | |
3493 | return 0; | |
3494 | ||
3495 | /* check if expand_top called, in which case don't need to clear */ | |
3496 | #if MORECORE_CLEARS | |
3497 | oldtop = top(ar_ptr); | |
3498 | oldtopsize = chunksize(top(ar_ptr)); | |
3499 | #endif | |
3500 | p = chunk_alloc (ar_ptr, sz); | |
3501 | ||
3502 | /* Only clearing follows, so we can unlock early. */ | |
3503 | (void)mutex_unlock(&ar_ptr->mutex); | |
3504 | ||
7799b7b3 UD |
3505 | if (p == 0) { |
3506 | /* Maybe the failure is due to running out of mmapped areas. */ | |
3507 | if(ar_ptr != &main_arena) { | |
3508 | (void)mutex_lock(&main_arena.mutex); | |
3509 | p = chunk_alloc(&main_arena, sz); | |
3510 | (void)mutex_unlock(&main_arena.mutex); | |
3511 | } | |
3512 | if (p == 0) return 0; | |
3513 | } | |
3514 | mem = chunk2mem(p); | |
f65fd747 | 3515 | |
7799b7b3 | 3516 | /* Two optional cases in which clearing not necessary */ |
f65fd747 UD |
3517 | |
3518 | #if HAVE_MMAP | |
7799b7b3 | 3519 | if (chunk_is_mmapped(p)) return mem; |
f65fd747 UD |
3520 | #endif |
3521 | ||
7799b7b3 | 3522 | csz = chunksize(p); |
f65fd747 UD |
3523 | |
3524 | #if MORECORE_CLEARS | |
7799b7b3 UD |
3525 | if (p == oldtop && csz > oldtopsize) { |
3526 | /* clear only the bytes from non-freshly-sbrked memory */ | |
3527 | csz = oldtopsize; | |
3528 | } | |
f65fd747 UD |
3529 | #endif |
3530 | ||
7799b7b3 UD |
3531 | MALLOC_ZERO(mem, csz - SIZE_SZ); |
3532 | return mem; | |
f65fd747 UD |
3533 | } |
3534 | ||
3535 | /* | |
3536 | ||
3537 | cfree just calls free. It is needed/defined on some systems | |
3538 | that pair it with calloc, presumably for odd historical reasons. | |
3539 | ||
3540 | */ | |
3541 | ||
3542 | #if !defined(_LIBC) | |
3543 | #if __STD_C | |
3544 | void cfree(Void_t *mem) | |
3545 | #else | |
3546 | void cfree(mem) Void_t *mem; | |
3547 | #endif | |
3548 | { | |
3549 | free(mem); | |
3550 | } | |
3551 | #endif | |
3552 | ||
3553 | \f | |
3554 | ||
3555 | /* | |
3556 | ||
3557 | Malloc_trim gives memory back to the system (via negative | |
3558 | arguments to sbrk) if there is unused memory at the `high' end of | |
3559 | the malloc pool. You can call this after freeing large blocks of | |
3560 | memory to potentially reduce the system-level memory requirements | |
3561 | of a program. However, it cannot guarantee to reduce memory. Under | |
3562 | some allocation patterns, some large free blocks of memory will be | |
3563 | locked between two used chunks, so they cannot be given back to | |
3564 | the system. | |
3565 | ||
3566 | The `pad' argument to malloc_trim represents the amount of free | |
3567 | trailing space to leave untrimmed. If this argument is zero, | |
3568 | only the minimum amount of memory to maintain internal data | |
3569 | structures will be left (one page or less). Non-zero arguments | |
3570 | can be supplied to maintain enough trailing space to service | |
3571 | future expected allocations without having to re-obtain memory | |
3572 | from the system. | |
3573 | ||
3574 | Malloc_trim returns 1 if it actually released any memory, else 0. | |
3575 | ||
3576 | */ | |
3577 | ||
3578 | #if __STD_C | |
7e3be507 | 3579 | int mALLOC_TRIm(size_t pad) |
f65fd747 | 3580 | #else |
7e3be507 | 3581 | int mALLOC_TRIm(pad) size_t pad; |
f65fd747 UD |
3582 | #endif |
3583 | { | |
3584 | int res; | |
3585 | ||
3586 | (void)mutex_lock(&main_arena.mutex); | |
8a4b65b4 | 3587 | res = main_trim(pad); |
f65fd747 UD |
3588 | (void)mutex_unlock(&main_arena.mutex); |
3589 | return res; | |
3590 | } | |
3591 | ||
8a4b65b4 UD |
3592 | /* Trim the main arena. */ |
3593 | ||
f65fd747 | 3594 | static int |
dfd2257a | 3595 | internal_function |
f65fd747 | 3596 | #if __STD_C |
8a4b65b4 | 3597 | main_trim(size_t pad) |
f65fd747 | 3598 | #else |
8a4b65b4 | 3599 | main_trim(pad) size_t pad; |
f65fd747 UD |
3600 | #endif |
3601 | { | |
3602 | mchunkptr top_chunk; /* The current top chunk */ | |
3603 | long top_size; /* Amount of top-most memory */ | |
3604 | long extra; /* Amount to release */ | |
3605 | char* current_brk; /* address returned by pre-check sbrk call */ | |
3606 | char* new_brk; /* address returned by negative sbrk call */ | |
3607 | ||
3608 | unsigned long pagesz = malloc_getpagesize; | |
3609 | ||
8a4b65b4 | 3610 | top_chunk = top(&main_arena); |
f65fd747 UD |
3611 | top_size = chunksize(top_chunk); |
3612 | extra = ((top_size - pad - MINSIZE + (pagesz-1)) / pagesz - 1) * pagesz; | |
3613 | ||
3614 | if (extra < (long)pagesz) /* Not enough memory to release */ | |
3615 | return 0; | |
3616 | ||
8a4b65b4 UD |
3617 | /* Test to make sure no one else called sbrk */ |
3618 | current_brk = (char*)(MORECORE (0)); | |
3619 | if (current_brk != (char*)(top_chunk) + top_size) | |
3620 | return 0; /* Apparently we don't own memory; must fail */ | |
f65fd747 | 3621 | |
8a4b65b4 | 3622 | new_brk = (char*)(MORECORE (-extra)); |
f65fd747 | 3623 | |
dfd2257a | 3624 | #if defined _LIBC || defined MALLOC_HOOKS |
1228ed5c UD |
3625 | /* Call the `morecore' hook if necessary. */ |
3626 | if (__after_morecore_hook) | |
3627 | (*__after_morecore_hook) (); | |
7799b7b3 | 3628 | #endif |
1228ed5c | 3629 | |
8a4b65b4 UD |
3630 | if (new_brk == (char*)(MORECORE_FAILURE)) { /* sbrk failed? */ |
3631 | /* Try to figure out what we have */ | |
3632 | current_brk = (char*)(MORECORE (0)); | |
3633 | top_size = current_brk - (char*)top_chunk; | |
3634 | if (top_size >= (long)MINSIZE) /* if not, we are very very dead! */ | |
3635 | { | |
3636 | sbrked_mem = current_brk - sbrk_base; | |
3637 | set_head(top_chunk, top_size | PREV_INUSE); | |
f65fd747 | 3638 | } |
8a4b65b4 UD |
3639 | check_chunk(&main_arena, top_chunk); |
3640 | return 0; | |
3641 | } | |
3642 | sbrked_mem -= extra; | |
3643 | ||
3644 | /* Success. Adjust top accordingly. */ | |
3645 | set_head(top_chunk, (top_size - extra) | PREV_INUSE); | |
3646 | check_chunk(&main_arena, top_chunk); | |
3647 | return 1; | |
3648 | } | |
f65fd747 UD |
3649 | |
3650 | #ifndef NO_THREADS | |
8a4b65b4 UD |
3651 | |
3652 | static int | |
dfd2257a | 3653 | internal_function |
8a4b65b4 UD |
3654 | #if __STD_C |
3655 | heap_trim(heap_info *heap, size_t pad) | |
3656 | #else | |
3657 | heap_trim(heap, pad) heap_info *heap; size_t pad; | |
f65fd747 | 3658 | #endif |
8a4b65b4 UD |
3659 | { |
3660 | unsigned long pagesz = malloc_getpagesize; | |
3661 | arena *ar_ptr = heap->ar_ptr; | |
3662 | mchunkptr top_chunk = top(ar_ptr), p, bck, fwd; | |
3663 | heap_info *prev_heap; | |
3664 | long new_size, top_size, extra; | |
3665 | ||
3666 | /* Can this heap go away completely ? */ | |
3667 | while(top_chunk == chunk_at_offset(heap, sizeof(*heap))) { | |
3668 | prev_heap = heap->prev; | |
3669 | p = chunk_at_offset(prev_heap, prev_heap->size - (MINSIZE-2*SIZE_SZ)); | |
3670 | assert(p->size == (0|PREV_INUSE)); /* must be fencepost */ | |
3671 | p = prev_chunk(p); | |
3672 | new_size = chunksize(p) + (MINSIZE-2*SIZE_SZ); | |
10dc2a90 | 3673 | assert(new_size>0 && new_size<(long)(2*MINSIZE)); |
8a4b65b4 UD |
3674 | if(!prev_inuse(p)) |
3675 | new_size += p->prev_size; | |
3676 | assert(new_size>0 && new_size<HEAP_MAX_SIZE); | |
3677 | if(new_size + (HEAP_MAX_SIZE - prev_heap->size) < pad + MINSIZE + pagesz) | |
3678 | break; | |
3679 | ar_ptr->size -= heap->size; | |
3680 | delete_heap(heap); | |
3681 | heap = prev_heap; | |
3682 | if(!prev_inuse(p)) { /* consolidate backward */ | |
3683 | p = prev_chunk(p); | |
3684 | unlink(p, bck, fwd); | |
3685 | } | |
3686 | assert(((unsigned long)((char*)p + new_size) & (pagesz-1)) == 0); | |
3687 | assert( ((char*)p + new_size) == ((char*)heap + heap->size) ); | |
3688 | top(ar_ptr) = top_chunk = p; | |
3689 | set_head(top_chunk, new_size | PREV_INUSE); | |
3690 | check_chunk(ar_ptr, top_chunk); | |
3691 | } | |
3692 | top_size = chunksize(top_chunk); | |
3693 | extra = ((top_size - pad - MINSIZE + (pagesz-1))/pagesz - 1) * pagesz; | |
3694 | if(extra < (long)pagesz) | |
3695 | return 0; | |
3696 | /* Try to shrink. */ | |
3697 | if(grow_heap(heap, -extra) != 0) | |
3698 | return 0; | |
3699 | ar_ptr->size -= extra; | |
f65fd747 UD |
3700 | |
3701 | /* Success. Adjust top accordingly. */ | |
3702 | set_head(top_chunk, (top_size - extra) | PREV_INUSE); | |
3703 | check_chunk(ar_ptr, top_chunk); | |
3704 | return 1; | |
3705 | } | |
3706 | ||
8a4b65b4 UD |
3707 | #endif |
3708 | ||
f65fd747 UD |
3709 | \f |
3710 | ||
3711 | /* | |
3712 | malloc_usable_size: | |
3713 | ||
3714 | This routine tells you how many bytes you can actually use in an | |
3715 | allocated chunk, which may be more than you requested (although | |
3716 | often not). You can use this many bytes without worrying about | |
3717 | overwriting other allocated objects. Not a particularly great | |
3718 | programming practice, but still sometimes useful. | |
3719 | ||
3720 | */ | |
3721 | ||
3722 | #if __STD_C | |
7e3be507 | 3723 | size_t mALLOC_USABLE_SIZe(Void_t* mem) |
f65fd747 | 3724 | #else |
7e3be507 | 3725 | size_t mALLOC_USABLE_SIZe(mem) Void_t* mem; |
f65fd747 UD |
3726 | #endif |
3727 | { | |
3728 | mchunkptr p; | |
3729 | ||
3730 | if (mem == 0) | |
3731 | return 0; | |
3732 | else | |
3733 | { | |
3734 | p = mem2chunk(mem); | |
3735 | if(!chunk_is_mmapped(p)) | |
3736 | { | |
3737 | if (!inuse(p)) return 0; | |
3738 | check_inuse_chunk(arena_for_ptr(mem), p); | |
3739 | return chunksize(p) - SIZE_SZ; | |
3740 | } | |
3741 | return chunksize(p) - 2*SIZE_SZ; | |
3742 | } | |
3743 | } | |
3744 | ||
3745 | ||
3746 | \f | |
3747 | ||
8a4b65b4 | 3748 | /* Utility to update mallinfo for malloc_stats() and mallinfo() */ |
f65fd747 | 3749 | |
8a4b65b4 UD |
3750 | static void |
3751 | #if __STD_C | |
3752 | malloc_update_mallinfo(arena *ar_ptr, struct mallinfo *mi) | |
3753 | #else | |
3754 | malloc_update_mallinfo(ar_ptr, mi) arena *ar_ptr; struct mallinfo *mi; | |
3755 | #endif | |
f65fd747 | 3756 | { |
f65fd747 UD |
3757 | int i, navail; |
3758 | mbinptr b; | |
3759 | mchunkptr p; | |
3760 | #if MALLOC_DEBUG | |
3761 | mchunkptr q; | |
3762 | #endif | |
3763 | INTERNAL_SIZE_T avail; | |
3764 | ||
f43ce637 UD |
3765 | /* Initialize the memory. */ |
3766 | memset (mi, '\0', sizeof (struct mallinfo)); | |
3767 | ||
f65fd747 UD |
3768 | (void)mutex_lock(&ar_ptr->mutex); |
3769 | avail = chunksize(top(ar_ptr)); | |
3770 | navail = ((long)(avail) >= (long)MINSIZE)? 1 : 0; | |
3771 | ||
3772 | for (i = 1; i < NAV; ++i) | |
3773 | { | |
3774 | b = bin_at(ar_ptr, i); | |
3775 | for (p = last(b); p != b; p = p->bk) | |
3776 | { | |
3777 | #if MALLOC_DEBUG | |
3778 | check_free_chunk(ar_ptr, p); | |
3779 | for (q = next_chunk(p); | |
8a4b65b4 | 3780 | q != top(ar_ptr) && inuse(q) && (long)chunksize(q) > 0; |
f65fd747 UD |
3781 | q = next_chunk(q)) |
3782 | check_inuse_chunk(ar_ptr, q); | |
3783 | #endif | |
3784 | avail += chunksize(p); | |
3785 | navail++; | |
3786 | } | |
3787 | } | |
3788 | ||
8a4b65b4 UD |
3789 | mi->arena = ar_ptr->size; |
3790 | mi->ordblks = navail; | |
3791 | mi->uordblks = ar_ptr->size - avail; | |
3792 | mi->fordblks = avail; | |
3793 | mi->hblks = n_mmaps; | |
3794 | mi->hblkhd = mmapped_mem; | |
3795 | mi->keepcost = chunksize(top(ar_ptr)); | |
f65fd747 UD |
3796 | |
3797 | (void)mutex_unlock(&ar_ptr->mutex); | |
3798 | } | |
3799 | ||
8a4b65b4 UD |
3800 | #if !defined(NO_THREADS) && MALLOC_DEBUG > 1 |
3801 | ||
3802 | /* Print the complete contents of a single heap to stderr. */ | |
3803 | ||
3804 | static void | |
3805 | #if __STD_C | |
3806 | dump_heap(heap_info *heap) | |
3807 | #else | |
3808 | dump_heap(heap) heap_info *heap; | |
3809 | #endif | |
3810 | { | |
3811 | char *ptr; | |
3812 | mchunkptr p; | |
3813 | ||
3814 | fprintf(stderr, "Heap %p, size %10lx:\n", heap, (long)heap->size); | |
3815 | ptr = (heap->ar_ptr != (arena*)(heap+1)) ? | |
3816 | (char*)(heap + 1) : (char*)(heap + 1) + sizeof(arena); | |
3817 | p = (mchunkptr)(((unsigned long)ptr + MALLOC_ALIGN_MASK) & | |
3818 | ~MALLOC_ALIGN_MASK); | |
3819 | for(;;) { | |
3820 | fprintf(stderr, "chunk %p size %10lx", p, (long)p->size); | |
3821 | if(p == top(heap->ar_ptr)) { | |
3822 | fprintf(stderr, " (top)\n"); | |
3823 | break; | |
3824 | } else if(p->size == (0|PREV_INUSE)) { | |
3825 | fprintf(stderr, " (fence)\n"); | |
3826 | break; | |
3827 | } | |
3828 | fprintf(stderr, "\n"); | |
3829 | p = next_chunk(p); | |
3830 | } | |
3831 | } | |
3832 | ||
3833 | #endif | |
3834 | ||
f65fd747 UD |
3835 | \f |
3836 | ||
3837 | /* | |
3838 | ||
3839 | malloc_stats: | |
3840 | ||
6d52618b | 3841 | For all arenas separately and in total, prints on stderr the |
8a4b65b4 | 3842 | amount of space obtained from the system, and the current number |
f65fd747 UD |
3843 | of bytes allocated via malloc (or realloc, etc) but not yet |
3844 | freed. (Note that this is the number of bytes allocated, not the | |
3845 | number requested. It will be larger than the number requested | |
8a4b65b4 UD |
3846 | because of alignment and bookkeeping overhead.) When not compiled |
3847 | for multiple threads, the maximum amount of allocated memory | |
3848 | (which may be more than current if malloc_trim and/or munmap got | |
3849 | called) is also reported. When using mmap(), prints the maximum | |
3850 | number of simultaneous mmap regions used, too. | |
f65fd747 UD |
3851 | |
3852 | */ | |
3853 | ||
7e3be507 | 3854 | void mALLOC_STATs() |
f65fd747 | 3855 | { |
8a4b65b4 UD |
3856 | int i; |
3857 | arena *ar_ptr; | |
3858 | struct mallinfo mi; | |
3859 | unsigned int in_use_b = mmapped_mem, system_b = in_use_b; | |
3860 | #if THREAD_STATS | |
3861 | long stat_lock_direct = 0, stat_lock_loop = 0, stat_lock_wait = 0; | |
3862 | #endif | |
3863 | ||
7e3be507 | 3864 | for(i=0, ar_ptr = &main_arena;; i++) { |
8a4b65b4 UD |
3865 | malloc_update_mallinfo(ar_ptr, &mi); |
3866 | fprintf(stderr, "Arena %d:\n", i); | |
3867 | fprintf(stderr, "system bytes = %10u\n", (unsigned int)mi.arena); | |
3868 | fprintf(stderr, "in use bytes = %10u\n", (unsigned int)mi.uordblks); | |
3869 | system_b += mi.arena; | |
3870 | in_use_b += mi.uordblks; | |
3871 | #if THREAD_STATS | |
3872 | stat_lock_direct += ar_ptr->stat_lock_direct; | |
3873 | stat_lock_loop += ar_ptr->stat_lock_loop; | |
3874 | stat_lock_wait += ar_ptr->stat_lock_wait; | |
3875 | #endif | |
3876 | #if !defined(NO_THREADS) && MALLOC_DEBUG > 1 | |
3877 | if(ar_ptr != &main_arena) { | |
c131718c | 3878 | heap_info *heap; |
7e3be507 | 3879 | (void)mutex_lock(&ar_ptr->mutex); |
c131718c | 3880 | heap = heap_for_ptr(top(ar_ptr)); |
8a4b65b4 | 3881 | while(heap) { dump_heap(heap); heap = heap->prev; } |
7e3be507 | 3882 | (void)mutex_unlock(&ar_ptr->mutex); |
8a4b65b4 UD |
3883 | } |
3884 | #endif | |
7e3be507 UD |
3885 | ar_ptr = ar_ptr->next; |
3886 | if(ar_ptr == &main_arena) break; | |
8a4b65b4 | 3887 | } |
7799b7b3 | 3888 | #if HAVE_MMAP |
8a4b65b4 | 3889 | fprintf(stderr, "Total (incl. mmap):\n"); |
7799b7b3 UD |
3890 | #else |
3891 | fprintf(stderr, "Total:\n"); | |
3892 | #endif | |
8a4b65b4 UD |
3893 | fprintf(stderr, "system bytes = %10u\n", system_b); |
3894 | fprintf(stderr, "in use bytes = %10u\n", in_use_b); | |
3895 | #ifdef NO_THREADS | |
3896 | fprintf(stderr, "max system bytes = %10u\n", (unsigned int)max_total_mem); | |
3897 | #endif | |
f65fd747 | 3898 | #if HAVE_MMAP |
8a4b65b4 | 3899 | fprintf(stderr, "max mmap regions = %10u\n", (unsigned int)max_n_mmaps); |
7799b7b3 | 3900 | fprintf(stderr, "max mmap bytes = %10lu\n", max_mmapped_mem); |
f65fd747 UD |
3901 | #endif |
3902 | #if THREAD_STATS | |
8a4b65b4 | 3903 | fprintf(stderr, "heaps created = %10d\n", stat_n_heaps); |
f65fd747 UD |
3904 | fprintf(stderr, "locked directly = %10ld\n", stat_lock_direct); |
3905 | fprintf(stderr, "locked in loop = %10ld\n", stat_lock_loop); | |
8a4b65b4 UD |
3906 | fprintf(stderr, "locked waiting = %10ld\n", stat_lock_wait); |
3907 | fprintf(stderr, "locked total = %10ld\n", | |
3908 | stat_lock_direct + stat_lock_loop + stat_lock_wait); | |
f65fd747 UD |
3909 | #endif |
3910 | } | |
3911 | ||
3912 | /* | |
3913 | mallinfo returns a copy of updated current mallinfo. | |
8a4b65b4 | 3914 | The information reported is for the arena last used by the thread. |
f65fd747 UD |
3915 | */ |
3916 | ||
3917 | struct mallinfo mALLINFo() | |
3918 | { | |
8a4b65b4 UD |
3919 | struct mallinfo mi; |
3920 | Void_t *vptr = NULL; | |
3921 | ||
1228ed5c | 3922 | #ifndef NO_THREADS |
8a4b65b4 | 3923 | tsd_getspecific(arena_key, vptr); |
1228ed5c | 3924 | #endif |
8a4b65b4 UD |
3925 | malloc_update_mallinfo((vptr ? (arena*)vptr : &main_arena), &mi); |
3926 | return mi; | |
f65fd747 UD |
3927 | } |
3928 | ||
3929 | ||
3930 | \f | |
3931 | ||
3932 | /* | |
3933 | mallopt: | |
3934 | ||
3935 | mallopt is the general SVID/XPG interface to tunable parameters. | |
3936 | The format is to provide a (parameter-number, parameter-value) pair. | |
3937 | mallopt then sets the corresponding parameter to the argument | |
3938 | value if it can (i.e., so long as the value is meaningful), | |
3939 | and returns 1 if successful else 0. | |
3940 | ||
3941 | See descriptions of tunable parameters above. | |
3942 | ||
3943 | */ | |
3944 | ||
3945 | #if __STD_C | |
3946 | int mALLOPt(int param_number, int value) | |
3947 | #else | |
3948 | int mALLOPt(param_number, value) int param_number; int value; | |
3949 | #endif | |
3950 | { | |
3951 | switch(param_number) | |
3952 | { | |
3953 | case M_TRIM_THRESHOLD: | |
3954 | trim_threshold = value; return 1; | |
3955 | case M_TOP_PAD: | |
3956 | top_pad = value; return 1; | |
3957 | case M_MMAP_THRESHOLD: | |
3958 | #ifndef NO_THREADS | |
3959 | /* Forbid setting the threshold too high. */ | |
3960 | if((unsigned long)value > HEAP_MAX_SIZE/2) return 0; | |
3961 | #endif | |
3962 | mmap_threshold = value; return 1; | |
3963 | case M_MMAP_MAX: | |
3964 | #if HAVE_MMAP | |
3965 | n_mmaps_max = value; return 1; | |
3966 | #else | |
3967 | if (value != 0) return 0; else n_mmaps_max = value; return 1; | |
3968 | #endif | |
10dc2a90 UD |
3969 | case M_CHECK_ACTION: |
3970 | check_action = value; return 1; | |
f65fd747 UD |
3971 | |
3972 | default: | |
3973 | return 0; | |
3974 | } | |
3975 | } | |
10dc2a90 | 3976 | |
10dc2a90 UD |
3977 | \f |
3978 | ||
2f6d1f1b UD |
3979 | /* Get/set state: malloc_get_state() records the current state of all |
3980 | malloc variables (_except_ for the actual heap contents and `hook' | |
3981 | function pointers) in a system dependent, opaque data structure. | |
3982 | This data structure is dynamically allocated and can be free()d | |
3983 | after use. malloc_set_state() restores the state of all malloc | |
3984 | variables to the previously obtained state. This is especially | |
3985 | useful when using this malloc as part of a shared library, and when | |
3986 | the heap contents are saved/restored via some other method. The | |
3987 | primary example for this is GNU Emacs with its `dumping' procedure. | |
3988 | `Hook' function pointers are never saved or restored by these | |
3989 | functions. */ | |
3990 | ||
3991 | #define MALLOC_STATE_MAGIC 0x444c4541l | |
3992 | #define MALLOC_STATE_VERSION (0*0x100l + 0l) /* major*0x100 + minor */ | |
3993 | ||
3994 | struct malloc_state { | |
3995 | long magic; | |
3996 | long version; | |
3997 | mbinptr av[NAV * 2 + 2]; | |
3998 | char* sbrk_base; | |
3999 | int sbrked_mem_bytes; | |
4000 | unsigned long trim_threshold; | |
4001 | unsigned long top_pad; | |
4002 | unsigned int n_mmaps_max; | |
4003 | unsigned long mmap_threshold; | |
4004 | int check_action; | |
4005 | unsigned long max_sbrked_mem; | |
4006 | unsigned long max_total_mem; | |
4007 | unsigned int n_mmaps; | |
4008 | unsigned int max_n_mmaps; | |
4009 | unsigned long mmapped_mem; | |
4010 | unsigned long max_mmapped_mem; | |
4011 | }; | |
4012 | ||
4013 | Void_t* | |
4014 | mALLOC_GET_STATe() | |
4015 | { | |
4016 | mchunkptr victim; | |
4017 | struct malloc_state* ms; | |
4018 | int i; | |
4019 | mbinptr b; | |
4020 | ||
4021 | ptmalloc_init(); | |
4022 | (void)mutex_lock(&main_arena.mutex); | |
4023 | victim = chunk_alloc(&main_arena, request2size(sizeof(*ms))); | |
4024 | if(!victim) { | |
4025 | (void)mutex_unlock(&main_arena.mutex); | |
4026 | return 0; | |
4027 | } | |
4028 | ms = (struct malloc_state*)chunk2mem(victim); | |
4029 | ms->magic = MALLOC_STATE_MAGIC; | |
4030 | ms->version = MALLOC_STATE_VERSION; | |
4031 | ms->av[0] = main_arena.av[0]; | |
4032 | ms->av[1] = main_arena.av[1]; | |
4033 | for(i=0; i<NAV; i++) { | |
4034 | b = bin_at(&main_arena, i); | |
4035 | if(first(b) == b) | |
4036 | ms->av[2*i+2] = ms->av[2*i+3] = 0; /* empty bin (or initial top) */ | |
4037 | else { | |
4038 | ms->av[2*i+2] = first(b); | |
4039 | ms->av[2*i+3] = last(b); | |
4040 | } | |
4041 | } | |
4042 | ms->sbrk_base = sbrk_base; | |
4043 | ms->sbrked_mem_bytes = sbrked_mem; | |
4044 | ms->trim_threshold = trim_threshold; | |
4045 | ms->top_pad = top_pad; | |
4046 | ms->n_mmaps_max = n_mmaps_max; | |
4047 | ms->mmap_threshold = mmap_threshold; | |
4048 | ms->check_action = check_action; | |
4049 | ms->max_sbrked_mem = max_sbrked_mem; | |
4050 | #ifdef NO_THREADS | |
4051 | ms->max_total_mem = max_total_mem; | |
4052 | #else | |
4053 | ms->max_total_mem = 0; | |
4054 | #endif | |
4055 | ms->n_mmaps = n_mmaps; | |
4056 | ms->max_n_mmaps = max_n_mmaps; | |
4057 | ms->mmapped_mem = mmapped_mem; | |
4058 | ms->max_mmapped_mem = max_mmapped_mem; | |
4059 | (void)mutex_unlock(&main_arena.mutex); | |
4060 | return (Void_t*)ms; | |
4061 | } | |
4062 | ||
4063 | int | |
4064 | #if __STD_C | |
4065 | mALLOC_SET_STATe(Void_t* msptr) | |
4066 | #else | |
4067 | mALLOC_SET_STATe(msptr) Void_t* msptr; | |
4068 | #endif | |
4069 | { | |
4070 | struct malloc_state* ms = (struct malloc_state*)msptr; | |
4071 | int i; | |
4072 | mbinptr b; | |
4073 | ||
4074 | ptmalloc_init(); | |
4075 | if(ms->magic != MALLOC_STATE_MAGIC) return -1; | |
4076 | /* Must fail if the major version is too high. */ | |
4077 | if((ms->version & ~0xffl) > (MALLOC_STATE_VERSION & ~0xffl)) return -2; | |
4078 | (void)mutex_lock(&main_arena.mutex); | |
4079 | main_arena.av[0] = ms->av[0]; | |
4080 | main_arena.av[1] = ms->av[1]; | |
4081 | for(i=0; i<NAV; i++) { | |
4082 | b = bin_at(&main_arena, i); | |
4083 | if(ms->av[2*i+2] == 0) | |
4084 | first(b) = last(b) = b; | |
4085 | else { | |
4086 | first(b) = ms->av[2*i+2]; | |
4087 | last(b) = ms->av[2*i+3]; | |
4088 | if(i > 0) { | |
4089 | /* Make sure the links to the `av'-bins in the heap are correct. */ | |
4090 | first(b)->bk = b; | |
4091 | last(b)->fd = b; | |
4092 | } | |
4093 | } | |
4094 | } | |
4095 | sbrk_base = ms->sbrk_base; | |
4096 | sbrked_mem = ms->sbrked_mem_bytes; | |
4097 | trim_threshold = ms->trim_threshold; | |
4098 | top_pad = ms->top_pad; | |
4099 | n_mmaps_max = ms->n_mmaps_max; | |
4100 | mmap_threshold = ms->mmap_threshold; | |
4101 | check_action = ms->check_action; | |
4102 | max_sbrked_mem = ms->max_sbrked_mem; | |
4103 | #ifdef NO_THREADS | |
4104 | max_total_mem = ms->max_total_mem; | |
4105 | #endif | |
4106 | n_mmaps = ms->n_mmaps; | |
4107 | max_n_mmaps = ms->max_n_mmaps; | |
4108 | mmapped_mem = ms->mmapped_mem; | |
4109 | max_mmapped_mem = ms->max_mmapped_mem; | |
4110 | /* add version-dependent code here */ | |
4111 | (void)mutex_unlock(&main_arena.mutex); | |
4112 | return 0; | |
4113 | } | |
4114 | ||
4115 | \f | |
4116 | ||
dfd2257a | 4117 | #if defined _LIBC || defined MALLOC_HOOKS |
10dc2a90 UD |
4118 | |
4119 | /* A simple, standard set of debugging hooks. Overhead is `only' one | |
4120 | byte per chunk; still this will catch most cases of double frees or | |
4121 | overruns. */ | |
4122 | ||
c0e45674 | 4123 | #define MAGICBYTE(p) ( ( ((size_t)p >> 3) ^ ((size_t)p >> 11)) & 0xFF ) |
f65fd747 | 4124 | |
10dc2a90 UD |
4125 | /* Convert a pointer to be free()d or realloc()ed to a valid chunk |
4126 | pointer. If the provided pointer is not valid, return NULL. The | |
4127 | goal here is to avoid crashes, unlike in the MALLOC_DEBUG code. */ | |
4128 | ||
4129 | static mchunkptr | |
dfd2257a | 4130 | internal_function |
10dc2a90 UD |
4131 | #if __STD_C |
4132 | mem2chunk_check(Void_t* mem) | |
4133 | #else | |
4134 | mem2chunk_check(mem) Void_t* mem; | |
f65fd747 | 4135 | #endif |
10dc2a90 UD |
4136 | { |
4137 | mchunkptr p; | |
4138 | INTERNAL_SIZE_T sz; | |
4139 | ||
4140 | p = mem2chunk(mem); | |
4141 | if(!aligned_OK(p)) return NULL; | |
4142 | if( (char*)p>=sbrk_base && (char*)p<(sbrk_base+sbrked_mem) ) { | |
7e3be507 | 4143 | /* Must be a chunk in conventional heap memory. */ |
10dc2a90 UD |
4144 | if(chunk_is_mmapped(p) || |
4145 | ( (sz = chunksize(p)), ((char*)p + sz)>=(sbrk_base+sbrked_mem) ) || | |
7e3be507 UD |
4146 | sz<MINSIZE || sz&MALLOC_ALIGN_MASK || !inuse(p) || |
4147 | ( !prev_inuse(p) && (p->prev_size&MALLOC_ALIGN_MASK || | |
4148 | (long)prev_chunk(p)<(long)sbrk_base || | |
4149 | next_chunk(prev_chunk(p))!=p) )) | |
4150 | return NULL; | |
4151 | if(*((unsigned char*)p + sz + (SIZE_SZ-1)) != MAGICBYTE(p)) | |
4152 | return NULL; | |
4153 | *((unsigned char*)p + sz + (SIZE_SZ-1)) ^= 0xFF; | |
10dc2a90 UD |
4154 | } else { |
4155 | unsigned long offset, page_mask = malloc_getpagesize-1; | |
4156 | ||
7e3be507 | 4157 | /* mmap()ed chunks have MALLOC_ALIGNMENT or higher power-of-two |
10dc2a90 UD |
4158 | alignment relative to the beginning of a page. Check this |
4159 | first. */ | |
4160 | offset = (unsigned long)mem & page_mask; | |
4161 | if((offset!=MALLOC_ALIGNMENT && offset!=0 && offset!=0x10 && | |
7e3be507 UD |
4162 | offset!=0x20 && offset!=0x40 && offset!=0x80 && offset!=0x100 && |
4163 | offset!=0x200 && offset!=0x400 && offset!=0x800 && offset!=0x1000 && | |
4164 | offset<0x2000) || | |
10dc2a90 UD |
4165 | !chunk_is_mmapped(p) || (p->size & PREV_INUSE) || |
4166 | ( (((unsigned long)p - p->prev_size) & page_mask) != 0 ) || | |
4167 | ( (sz = chunksize(p)), ((p->prev_size + sz) & page_mask) != 0 ) ) | |
4168 | return NULL; | |
7e3be507 UD |
4169 | if(*((unsigned char*)p + sz - 1) != MAGICBYTE(p)) |
4170 | return NULL; | |
4171 | *((unsigned char*)p + sz - 1) ^= 0xFF; | |
10dc2a90 UD |
4172 | } |
4173 | return p; | |
4174 | } | |
4175 | ||
4176 | static Void_t* | |
4177 | #if __STD_C | |
dfd2257a | 4178 | malloc_check(size_t sz, const Void_t *caller) |
10dc2a90 | 4179 | #else |
dfd2257a | 4180 | malloc_check(sz, caller) size_t sz; const Void_t *caller; |
a2b08ee5 | 4181 | #endif |
10dc2a90 UD |
4182 | { |
4183 | mchunkptr victim; | |
4184 | INTERNAL_SIZE_T nb = request2size(sz + 1); | |
4185 | ||
4186 | (void)mutex_lock(&main_arena.mutex); | |
4187 | victim = chunk_alloc(&main_arena, nb); | |
4188 | (void)mutex_unlock(&main_arena.mutex); | |
4189 | if(!victim) return NULL; | |
4190 | nb = chunksize(victim); | |
4191 | if(chunk_is_mmapped(victim)) | |
4192 | --nb; | |
4193 | else | |
4194 | nb += SIZE_SZ - 1; | |
7e3be507 | 4195 | *((unsigned char*)victim + nb) = MAGICBYTE(victim); |
10dc2a90 UD |
4196 | return chunk2mem(victim); |
4197 | } | |
4198 | ||
4199 | static void | |
4200 | #if __STD_C | |
dfd2257a | 4201 | free_check(Void_t* mem, const Void_t *caller) |
10dc2a90 | 4202 | #else |
dfd2257a | 4203 | free_check(mem, caller) Void_t* mem; const Void_t *caller; |
a2b08ee5 | 4204 | #endif |
10dc2a90 UD |
4205 | { |
4206 | mchunkptr p; | |
4207 | ||
4208 | if(!mem) return; | |
7e3be507 | 4209 | (void)mutex_lock(&main_arena.mutex); |
10dc2a90 UD |
4210 | p = mem2chunk_check(mem); |
4211 | if(!p) { | |
7e3be507 | 4212 | (void)mutex_unlock(&main_arena.mutex); |
10dc2a90 UD |
4213 | switch(check_action) { |
4214 | case 1: | |
4215 | fprintf(stderr, "free(): invalid pointer %lx!\n", (long)(mem)); | |
4216 | break; | |
4217 | case 2: | |
4218 | abort(); | |
4219 | } | |
4220 | return; | |
4221 | } | |
4222 | #if HAVE_MMAP | |
4223 | if (chunk_is_mmapped(p)) { | |
7e3be507 | 4224 | (void)mutex_unlock(&main_arena.mutex); |
10dc2a90 UD |
4225 | munmap_chunk(p); |
4226 | return; | |
4227 | } | |
4228 | #endif | |
7e3be507 UD |
4229 | #if 0 /* Erase freed memory. */ |
4230 | memset(mem, 0, chunksize(p) - (SIZE_SZ+1)); | |
4231 | #endif | |
10dc2a90 UD |
4232 | chunk_free(&main_arena, p); |
4233 | (void)mutex_unlock(&main_arena.mutex); | |
4234 | } | |
4235 | ||
4236 | static Void_t* | |
4237 | #if __STD_C | |
dfd2257a | 4238 | realloc_check(Void_t* oldmem, size_t bytes, const Void_t *caller) |
10dc2a90 | 4239 | #else |
dfd2257a UD |
4240 | realloc_check(oldmem, bytes, caller) |
4241 | Void_t* oldmem; size_t bytes; const Void_t *caller; | |
a2b08ee5 | 4242 | #endif |
10dc2a90 UD |
4243 | { |
4244 | mchunkptr oldp, newp; | |
4245 | INTERNAL_SIZE_T nb, oldsize; | |
4246 | ||
a2b08ee5 | 4247 | if (oldmem == 0) return malloc_check(bytes, NULL); |
7e3be507 | 4248 | (void)mutex_lock(&main_arena.mutex); |
10dc2a90 UD |
4249 | oldp = mem2chunk_check(oldmem); |
4250 | if(!oldp) { | |
7e3be507 | 4251 | (void)mutex_unlock(&main_arena.mutex); |
10dc2a90 UD |
4252 | switch(check_action) { |
4253 | case 1: | |
4254 | fprintf(stderr, "realloc(): invalid pointer %lx!\n", (long)(oldmem)); | |
4255 | break; | |
4256 | case 2: | |
4257 | abort(); | |
4258 | } | |
a2b08ee5 | 4259 | return malloc_check(bytes, NULL); |
10dc2a90 UD |
4260 | } |
4261 | oldsize = chunksize(oldp); | |
4262 | ||
4263 | nb = request2size(bytes+1); | |
4264 | ||
10dc2a90 UD |
4265 | #if HAVE_MMAP |
4266 | if (chunk_is_mmapped(oldp)) { | |
4267 | #if HAVE_MREMAP | |
4268 | newp = mremap_chunk(oldp, nb); | |
4269 | if(!newp) { | |
4270 | #endif | |
4271 | /* Note the extra SIZE_SZ overhead. */ | |
4272 | if(oldsize - SIZE_SZ >= nb) newp = oldp; /* do nothing */ | |
4273 | else { | |
7e3be507 UD |
4274 | /* Must alloc, copy, free. */ |
4275 | newp = chunk_alloc(&main_arena, nb); | |
4276 | if (newp) { | |
4277 | MALLOC_COPY(chunk2mem(newp), oldmem, oldsize - 2*SIZE_SZ); | |
4278 | munmap_chunk(oldp); | |
4279 | } | |
10dc2a90 UD |
4280 | } |
4281 | #if HAVE_MREMAP | |
4282 | } | |
4283 | #endif | |
7e3be507 | 4284 | } else { |
10dc2a90 UD |
4285 | #endif /* HAVE_MMAP */ |
4286 | newp = chunk_realloc(&main_arena, oldp, oldsize, nb); | |
7e3be507 UD |
4287 | #if 0 /* Erase freed memory. */ |
4288 | nb = chunksize(newp); | |
4289 | if(oldp<newp || oldp>=chunk_at_offset(newp, nb)) { | |
4290 | memset((char*)oldmem + 2*sizeof(mbinptr), 0, | |
4291 | oldsize - (2*sizeof(mbinptr)+2*SIZE_SZ+1)); | |
4292 | } else if(nb > oldsize+SIZE_SZ) { | |
4293 | memset((char*)chunk2mem(newp) + oldsize, 0, nb - (oldsize+SIZE_SZ)); | |
4294 | } | |
4295 | #endif | |
4296 | #if HAVE_MMAP | |
4297 | } | |
4298 | #endif | |
10dc2a90 UD |
4299 | (void)mutex_unlock(&main_arena.mutex); |
4300 | ||
4301 | if(!newp) return NULL; | |
4302 | nb = chunksize(newp); | |
4303 | if(chunk_is_mmapped(newp)) | |
4304 | --nb; | |
4305 | else | |
4306 | nb += SIZE_SZ - 1; | |
7e3be507 | 4307 | *((unsigned char*)newp + nb) = MAGICBYTE(newp); |
10dc2a90 UD |
4308 | return chunk2mem(newp); |
4309 | } | |
4310 | ||
4311 | static Void_t* | |
4312 | #if __STD_C | |
dfd2257a | 4313 | memalign_check(size_t alignment, size_t bytes, const Void_t *caller) |
10dc2a90 | 4314 | #else |
dfd2257a UD |
4315 | memalign_check(alignment, bytes, caller) |
4316 | size_t alignment; size_t bytes; const Void_t *caller; | |
a2b08ee5 | 4317 | #endif |
10dc2a90 UD |
4318 | { |
4319 | INTERNAL_SIZE_T nb; | |
4320 | mchunkptr p; | |
4321 | ||
a2b08ee5 | 4322 | if (alignment <= MALLOC_ALIGNMENT) return malloc_check(bytes, NULL); |
10dc2a90 UD |
4323 | if (alignment < MINSIZE) alignment = MINSIZE; |
4324 | ||
4325 | nb = request2size(bytes+1); | |
4326 | (void)mutex_lock(&main_arena.mutex); | |
4327 | p = chunk_align(&main_arena, nb, alignment); | |
4328 | (void)mutex_unlock(&main_arena.mutex); | |
4329 | if(!p) return NULL; | |
4330 | nb = chunksize(p); | |
4331 | if(chunk_is_mmapped(p)) | |
4332 | --nb; | |
4333 | else | |
4334 | nb += SIZE_SZ - 1; | |
7e3be507 | 4335 | *((unsigned char*)p + nb) = MAGICBYTE(p); |
10dc2a90 UD |
4336 | return chunk2mem(p); |
4337 | } | |
4338 | ||
7e3be507 UD |
4339 | /* The following hooks are used when the global initialization in |
4340 | ptmalloc_init() hasn't completed yet. */ | |
4341 | ||
4342 | static Void_t* | |
4343 | #if __STD_C | |
dfd2257a | 4344 | malloc_starter(size_t sz, const Void_t *caller) |
7e3be507 | 4345 | #else |
dfd2257a | 4346 | malloc_starter(sz, caller) size_t sz; const Void_t *caller; |
a2b08ee5 | 4347 | #endif |
7e3be507 UD |
4348 | { |
4349 | mchunkptr victim = chunk_alloc(&main_arena, request2size(sz)); | |
4350 | ||
4351 | return victim ? chunk2mem(victim) : 0; | |
4352 | } | |
4353 | ||
4354 | static void | |
4355 | #if __STD_C | |
dfd2257a | 4356 | free_starter(Void_t* mem, const Void_t *caller) |
7e3be507 | 4357 | #else |
dfd2257a | 4358 | free_starter(mem, caller) Void_t* mem; const Void_t *caller; |
a2b08ee5 | 4359 | #endif |
7e3be507 UD |
4360 | { |
4361 | mchunkptr p; | |
4362 | ||
4363 | if(!mem) return; | |
4364 | p = mem2chunk(mem); | |
4365 | #if HAVE_MMAP | |
4366 | if (chunk_is_mmapped(p)) { | |
4367 | munmap_chunk(p); | |
4368 | return; | |
4369 | } | |
4370 | #endif | |
4371 | chunk_free(&main_arena, p); | |
4372 | } | |
4373 | ||
ca34d7a7 UD |
4374 | /* The following hooks are used while the `atfork' handling mechanism |
4375 | is active. */ | |
4376 | ||
4377 | static Void_t* | |
4378 | #if __STD_C | |
dfd2257a | 4379 | malloc_atfork (size_t sz, const Void_t *caller) |
ca34d7a7 | 4380 | #else |
dfd2257a | 4381 | malloc_atfork(sz, caller) size_t sz; const Void_t *caller; |
a2b08ee5 | 4382 | #endif |
ca34d7a7 UD |
4383 | { |
4384 | Void_t *vptr = NULL; | |
4385 | ||
4386 | tsd_getspecific(arena_key, vptr); | |
4387 | if(!vptr) { | |
4388 | mchunkptr victim = chunk_alloc(&main_arena, request2size(sz)); | |
4389 | return victim ? chunk2mem(victim) : 0; | |
4390 | } else { | |
4391 | /* Suspend the thread until the `atfork' handlers have completed. | |
4392 | By that time, the hooks will have been reset as well, so that | |
4393 | mALLOc() can be used again. */ | |
4394 | (void)mutex_lock(&list_lock); | |
4395 | (void)mutex_unlock(&list_lock); | |
4396 | return mALLOc(sz); | |
4397 | } | |
4398 | } | |
4399 | ||
4400 | static void | |
4401 | #if __STD_C | |
dfd2257a | 4402 | free_atfork(Void_t* mem, const Void_t *caller) |
ca34d7a7 | 4403 | #else |
dfd2257a | 4404 | free_atfork(mem, caller) Void_t* mem; const Void_t *caller; |
a2b08ee5 | 4405 | #endif |
ca34d7a7 UD |
4406 | { |
4407 | Void_t *vptr = NULL; | |
4408 | arena *ar_ptr; | |
4409 | mchunkptr p; /* chunk corresponding to mem */ | |
4410 | ||
4411 | if (mem == 0) /* free(0) has no effect */ | |
4412 | return; | |
4413 | ||
4414 | p = mem2chunk(mem); | |
4415 | ||
4416 | #if HAVE_MMAP | |
4417 | if (chunk_is_mmapped(p)) /* release mmapped memory. */ | |
4418 | { | |
4419 | munmap_chunk(p); | |
4420 | return; | |
4421 | } | |
4422 | #endif | |
4423 | ||
4424 | ar_ptr = arena_for_ptr(p); | |
4425 | tsd_getspecific(arena_key, vptr); | |
4426 | if(vptr) | |
4427 | (void)mutex_lock(&ar_ptr->mutex); | |
4428 | chunk_free(ar_ptr, p); | |
4429 | if(vptr) | |
4430 | (void)mutex_unlock(&ar_ptr->mutex); | |
4431 | } | |
4432 | ||
dfd2257a | 4433 | #endif /* defined _LIBC || defined MALLOC_HOOKS */ |
f65fd747 | 4434 | |
7e3be507 UD |
4435 | \f |
4436 | ||
4437 | #ifdef _LIBC | |
4438 | weak_alias (__libc_calloc, __calloc) weak_alias (__libc_calloc, calloc) | |
4439 | weak_alias (__libc_free, __cfree) weak_alias (__libc_free, cfree) | |
4440 | weak_alias (__libc_free, __free) weak_alias (__libc_free, free) | |
4441 | weak_alias (__libc_malloc, __malloc) weak_alias (__libc_malloc, malloc) | |
4442 | weak_alias (__libc_memalign, __memalign) weak_alias (__libc_memalign, memalign) | |
4443 | weak_alias (__libc_realloc, __realloc) weak_alias (__libc_realloc, realloc) | |
4444 | weak_alias (__libc_valloc, __valloc) weak_alias (__libc_valloc, valloc) | |
4445 | weak_alias (__libc_pvalloc, __pvalloc) weak_alias (__libc_pvalloc, pvalloc) | |
4446 | weak_alias (__libc_mallinfo, __mallinfo) weak_alias (__libc_mallinfo, mallinfo) | |
4447 | weak_alias (__libc_mallopt, __mallopt) weak_alias (__libc_mallopt, mallopt) | |
4448 | ||
4449 | weak_alias (__malloc_stats, malloc_stats) | |
4450 | weak_alias (__malloc_usable_size, malloc_usable_size) | |
4451 | weak_alias (__malloc_trim, malloc_trim) | |
2f6d1f1b UD |
4452 | weak_alias (__malloc_get_state, malloc_get_state) |
4453 | weak_alias (__malloc_set_state, malloc_set_state) | |
7e3be507 UD |
4454 | #endif |
4455 | ||
f65fd747 UD |
4456 | /* |
4457 | ||
4458 | History: | |
4459 | ||
2f6d1f1b UD |
4460 | V2.6.4-pt3 Thu Feb 20 1997 Wolfram Gloger (wmglo@dent.med.uni-muenchen.de) |
4461 | * Added malloc_get/set_state() (mainly for use in GNU emacs), | |
4462 | using interface from Marcus Daniels | |
4463 | * All parameters are now adjustable via environment variables | |
4464 | ||
10dc2a90 UD |
4465 | V2.6.4-pt2 Sat Dec 14 1996 Wolfram Gloger (wmglo@dent.med.uni-muenchen.de) |
4466 | * Added debugging hooks | |
4467 | * Fixed possible deadlock in realloc() when out of memory | |
4468 | * Don't pollute namespace in glibc: use __getpagesize, __mmap, etc. | |
4469 | ||
f65fd747 UD |
4470 | V2.6.4-pt Wed Dec 4 1996 Wolfram Gloger (wmglo@dent.med.uni-muenchen.de) |
4471 | * Very minor updates from the released 2.6.4 version. | |
4472 | * Trimmed include file down to exported data structures. | |
4473 | * Changes from H.J. Lu for glibc-2.0. | |
4474 | ||
4475 | V2.6.3i-pt Sep 16 1996 Wolfram Gloger (wmglo@dent.med.uni-muenchen.de) | |
4476 | * Many changes for multiple threads | |
4477 | * Introduced arenas and heaps | |
4478 | ||
4479 | V2.6.3 Sun May 19 08:17:58 1996 Doug Lea (dl at gee) | |
4480 | * Added pvalloc, as recommended by H.J. Liu | |
4481 | * Added 64bit pointer support mainly from Wolfram Gloger | |
4482 | * Added anonymously donated WIN32 sbrk emulation | |
4483 | * Malloc, calloc, getpagesize: add optimizations from Raymond Nijssen | |
4484 | * malloc_extend_top: fix mask error that caused wastage after | |
4485 | foreign sbrks | |
4486 | * Add linux mremap support code from HJ Liu | |
4487 | ||
4488 | V2.6.2 Tue Dec 5 06:52:55 1995 Doug Lea (dl at gee) | |
4489 | * Integrated most documentation with the code. | |
4490 | * Add support for mmap, with help from | |
4491 | Wolfram Gloger (Gloger@lrz.uni-muenchen.de). | |
4492 | * Use last_remainder in more cases. | |
4493 | * Pack bins using idea from colin@nyx10.cs.du.edu | |
6d52618b | 4494 | * Use ordered bins instead of best-fit threshold |
f65fd747 UD |
4495 | * Eliminate block-local decls to simplify tracing and debugging. |
4496 | * Support another case of realloc via move into top | |
6d52618b | 4497 | * Fix error occurring when initial sbrk_base not word-aligned. |
f65fd747 UD |
4498 | * Rely on page size for units instead of SBRK_UNIT to |
4499 | avoid surprises about sbrk alignment conventions. | |
4500 | * Add mallinfo, mallopt. Thanks to Raymond Nijssen | |
4501 | (raymond@es.ele.tue.nl) for the suggestion. | |
4502 | * Add `pad' argument to malloc_trim and top_pad mallopt parameter. | |
4503 | * More precautions for cases where other routines call sbrk, | |
4504 | courtesy of Wolfram Gloger (Gloger@lrz.uni-muenchen.de). | |
4505 | * Added macros etc., allowing use in linux libc from | |
4506 | H.J. Lu (hjl@gnu.ai.mit.edu) | |
4507 | * Inverted this history list | |
4508 | ||
4509 | V2.6.1 Sat Dec 2 14:10:57 1995 Doug Lea (dl at gee) | |
4510 | * Re-tuned and fixed to behave more nicely with V2.6.0 changes. | |
4511 | * Removed all preallocation code since under current scheme | |
4512 | the work required to undo bad preallocations exceeds | |
4513 | the work saved in good cases for most test programs. | |
4514 | * No longer use return list or unconsolidated bins since | |
4515 | no scheme using them consistently outperforms those that don't | |
4516 | given above changes. | |
4517 | * Use best fit for very large chunks to prevent some worst-cases. | |
4518 | * Added some support for debugging | |
4519 | ||
4520 | V2.6.0 Sat Nov 4 07:05:23 1995 Doug Lea (dl at gee) | |
4521 | * Removed footers when chunks are in use. Thanks to | |
4522 | Paul Wilson (wilson@cs.texas.edu) for the suggestion. | |
4523 | ||
4524 | V2.5.4 Wed Nov 1 07:54:51 1995 Doug Lea (dl at gee) | |
4525 | * Added malloc_trim, with help from Wolfram Gloger | |
4526 | (wmglo@Dent.MED.Uni-Muenchen.DE). | |
4527 | ||
4528 | V2.5.3 Tue Apr 26 10:16:01 1994 Doug Lea (dl at g) | |
4529 | ||
4530 | V2.5.2 Tue Apr 5 16:20:40 1994 Doug Lea (dl at g) | |
4531 | * realloc: try to expand in both directions | |
4532 | * malloc: swap order of clean-bin strategy; | |
4533 | * realloc: only conditionally expand backwards | |
4534 | * Try not to scavenge used bins | |
4535 | * Use bin counts as a guide to preallocation | |
4536 | * Occasionally bin return list chunks in first scan | |
4537 | * Add a few optimizations from colin@nyx10.cs.du.edu | |
4538 | ||
4539 | V2.5.1 Sat Aug 14 15:40:43 1993 Doug Lea (dl at g) | |
4540 | * faster bin computation & slightly different binning | |
4541 | * merged all consolidations to one part of malloc proper | |
4542 | (eliminating old malloc_find_space & malloc_clean_bin) | |
4543 | * Scan 2 returns chunks (not just 1) | |
4544 | * Propagate failure in realloc if malloc returns 0 | |
4545 | * Add stuff to allow compilation on non-ANSI compilers | |
4546 | from kpv@research.att.com | |
4547 | ||
4548 | V2.5 Sat Aug 7 07:41:59 1993 Doug Lea (dl at g.oswego.edu) | |
4549 | * removed potential for odd address access in prev_chunk | |
4550 | * removed dependency on getpagesize.h | |
4551 | * misc cosmetics and a bit more internal documentation | |
4552 | * anticosmetics: mangled names in macros to evade debugger strangeness | |
4553 | * tested on sparc, hp-700, dec-mips, rs6000 | |
4554 | with gcc & native cc (hp, dec only) allowing | |
4555 | Detlefs & Zorn comparison study (in SIGPLAN Notices.) | |
4556 | ||
4557 | Trial version Fri Aug 28 13:14:29 1992 Doug Lea (dl at g.oswego.edu) | |
4558 | * Based loosely on libg++-1.2X malloc. (It retains some of the overall | |
4559 | structure of old version, but most details differ.) | |
4560 | ||
4561 | */ |