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Commit | Line | Data |
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282113ba | 1 | /* process.cc |
f449bfef | 2 | |
f449bfef RC |
3 | Written by Robert Collins <rbtcollins@hotmail.com> |
4 | ||
1c001dd2 | 5 | This file is part of Cygwin. |
f449bfef | 6 | |
1c001dd2 CS |
7 | This software is a copyrighted work licensed under the terms of the |
8 | Cygwin license. Please consult the file "CYGWIN_LICENSE" for | |
9 | details. */ | |
f449bfef | 10 | |
1dcd520b | 11 | #ifdef __OUTSIDE_CYGWIN__ |
1c001dd2 CS |
12 | #include "woutsup.h" |
13 | ||
14 | #include <sys/types.h> | |
15 | ||
16 | #include <assert.h> | |
f449bfef | 17 | #include <stdlib.h> |
f449bfef | 18 | |
282113ba | 19 | #include "process.h" |
1c001dd2 | 20 | |
8d8f4036 CV |
21 | #include "cygserver_ipc.h" |
22 | ||
1c001dd2 CS |
23 | /*****************************************************************************/ |
24 | ||
25 | #define elements(ARRAY) (sizeof (ARRAY) / sizeof (*ARRAY)) | |
26 | ||
27 | /*****************************************************************************/ | |
28 | ||
29 | process_cleanup::~process_cleanup () | |
f449bfef | 30 | { |
282113ba | 31 | delete _process; |
f449bfef RC |
32 | } |
33 | ||
1c001dd2 CS |
34 | void |
35 | process_cleanup::process () | |
f449bfef | 36 | { |
1c001dd2 | 37 | _process->cleanup (); |
f449bfef RC |
38 | } |
39 | ||
1c001dd2 CS |
40 | /*****************************************************************************/ |
41 | ||
8d8f4036 | 42 | process::process (const pid_t cygpid, const DWORD winpid) |
1c001dd2 CS |
43 | : _cygpid (cygpid), |
44 | _winpid (winpid), | |
45 | _hProcess (NULL), | |
46 | _cleaning_up (false), | |
47 | _exit_status (STILL_ACTIVE), | |
48 | _routines_head (NULL), | |
49 | _next (NULL) | |
50 | { | |
51 | _hProcess = OpenProcess (PROCESS_ALL_ACCESS, FALSE, winpid); | |
52 | if (!_hProcess) | |
f449bfef | 53 | { |
681bb2f7 | 54 | system_printf ("unable to obtain handle for new cache process %d(%u)", |
1c001dd2 CS |
55 | _cygpid, _winpid); |
56 | _hProcess = INVALID_HANDLE_VALUE; | |
57 | _exit_status = 0; | |
f449bfef RC |
58 | } |
59 | else | |
681bb2f7 | 60 | debug_printf ("got handle %p for new cache process %d(%u)", |
1c001dd2 CS |
61 | _hProcess, _cygpid, _winpid); |
62 | InitializeCriticalSection (&_access); | |
681bb2f7 | 63 | debug ("initialized (%u)", _cygpid); |
f449bfef RC |
64 | } |
65 | ||
1c001dd2 | 66 | process::~process () |
f449bfef | 67 | { |
681bb2f7 | 68 | debug ("deleting (%u)", _cygpid); |
1c001dd2 | 69 | DeleteCriticalSection (&_access); |
373a036f | 70 | CloseHandle (_hProcess); |
f449bfef RC |
71 | } |
72 | ||
1c001dd2 | 73 | /* No need to be thread-safe as this is only ever called by |
2d015bd6 CV |
74 | * process_cache::check_and_remove_process (). If it has to be made |
75 | * thread-safe later on, it should not use the `access' critical section as | |
76 | * that is held by the client request handlers for an arbitrary length of time, | |
77 | * i.e. while they do whatever processing is required for a client request. | |
1c001dd2 CS |
78 | */ |
79 | DWORD | |
80 | process::check_exit_code () | |
f449bfef | 81 | { |
1c001dd2 CS |
82 | if (_hProcess && _hProcess != INVALID_HANDLE_VALUE |
83 | && _exit_status == STILL_ACTIVE | |
84 | && !GetExitCodeProcess (_hProcess, &_exit_status)) | |
85 | { | |
681bb2f7 | 86 | system_printf ("failed to retrieve exit code for %d(%u), error = %u", |
1c001dd2 CS |
87 | _cygpid, _winpid, GetLastError ()); |
88 | _hProcess = INVALID_HANDLE_VALUE; | |
89 | } | |
90 | return _exit_status; | |
f449bfef RC |
91 | } |
92 | ||
1c001dd2 CS |
93 | bool |
94 | process::add (cleanup_routine *const entry) | |
f449bfef | 95 | { |
1c001dd2 | 96 | assert (entry); |
f449bfef | 97 | |
1c001dd2 | 98 | bool res = false; |
1f8b3049 | 99 | hold (); |
1c001dd2 CS |
100 | |
101 | if (!_cleaning_up) | |
f449bfef | 102 | { |
1c001dd2 CS |
103 | entry->_next = _routines_head; |
104 | _routines_head = entry; | |
105 | res = true; | |
f449bfef | 106 | } |
1c001dd2 | 107 | |
1f8b3049 | 108 | release (); |
1c001dd2 CS |
109 | return res; |
110 | } | |
111 | ||
112 | bool | |
113 | process::remove (const cleanup_routine *const entry) | |
114 | { | |
115 | assert (entry); | |
116 | ||
117 | bool res = false; | |
1f8b3049 | 118 | hold (); |
1c001dd2 CS |
119 | |
120 | if (!_cleaning_up) | |
f449bfef | 121 | { |
1c001dd2 CS |
122 | cleanup_routine *previous = NULL; |
123 | ||
124 | for (cleanup_routine *ptr = _routines_head; | |
125 | ptr; | |
126 | previous = ptr, ptr = ptr->_next) | |
f449bfef | 127 | { |
1c001dd2 CS |
128 | if (*ptr == *entry) |
129 | { | |
130 | if (previous) | |
131 | previous->_next = ptr->_next; | |
132 | else | |
133 | _routines_head = ptr->_next; | |
134 | ||
282113ba | 135 | delete ptr; |
1c001dd2 CS |
136 | res = true; |
137 | break; | |
138 | } | |
f449bfef RC |
139 | } |
140 | } | |
1c001dd2 | 141 | |
1f8b3049 | 142 | release (); |
1c001dd2 | 143 | return res; |
f449bfef | 144 | } |
2402700d | 145 | |
1c001dd2 CS |
146 | /* This is single threaded. It's called after the process is removed |
147 | * from the cache, but inserts may be attemped by worker threads that | |
148 | * have a pointer to it. | |
f449bfef | 149 | */ |
1c001dd2 CS |
150 | void |
151 | process::cleanup () | |
f449bfef | 152 | { |
1f8b3049 | 153 | hold (); |
1c001dd2 CS |
154 | assert (!is_active ()); |
155 | assert (!_cleaning_up); | |
156 | InterlockedExchange (&_cleaning_up, true); | |
157 | cleanup_routine *entry = _routines_head; | |
158 | _routines_head = NULL; | |
1f8b3049 | 159 | release (); |
1c001dd2 CS |
160 | |
161 | while (entry) | |
f449bfef | 162 | { |
1c001dd2 CS |
163 | cleanup_routine *const ptr = entry; |
164 | entry = entry->_next; | |
165 | ptr->cleanup (this); | |
282113ba | 166 | delete ptr; |
f449bfef | 167 | } |
f449bfef RC |
168 | } |
169 | ||
1c001dd2 | 170 | /*****************************************************************************/ |
f449bfef RC |
171 | |
172 | void | |
1c001dd2 | 173 | process_cache::submission_loop::request_loop () |
f449bfef | 174 | { |
1c001dd2 CS |
175 | assert (this); |
176 | assert (_cache); | |
177 | assert (_interrupt_event); | |
178 | ||
179 | while (_running) | |
180 | _cache->wait_for_processes (_interrupt_event); | |
f449bfef RC |
181 | } |
182 | ||
1c001dd2 CS |
183 | /*****************************************************************************/ |
184 | ||
2d015bd6 CV |
185 | process_cache::process_cache (const size_t max_procs, |
186 | const unsigned int initial_workers) | |
1c001dd2 CS |
187 | : _queue (initial_workers), |
188 | _submitter (this, &_queue), // true == interruptible | |
189 | _processes_count (0), | |
2d015bd6 | 190 | _max_process_count (max_procs), |
1c001dd2 CS |
191 | _processes_head (NULL), |
192 | _cache_add_trigger (NULL) | |
f449bfef | 193 | { |
1c001dd2 CS |
194 | /* there can only be one */ |
195 | InitializeCriticalSection (&_cache_write_access); | |
196 | ||
197 | _cache_add_trigger = CreateEvent (NULL, // SECURITY_ATTRIBUTES | |
2d015bd6 | 198 | TRUE, // Manual-reset |
1c001dd2 CS |
199 | FALSE, // Initially non-signalled |
200 | NULL); // Anonymous | |
201 | ||
202 | if (!_cache_add_trigger) | |
f449bfef | 203 | { |
681bb2f7 | 204 | system_printf ("failed to create cache add trigger, error = %u", |
1c001dd2 CS |
205 | GetLastError ()); |
206 | abort (); | |
f449bfef | 207 | } |
f449bfef | 208 | |
1c001dd2 | 209 | _queue.add_submission_loop (&_submitter); |
f449bfef RC |
210 | } |
211 | ||
1c001dd2 | 212 | process_cache::~process_cache () |
f449bfef | 213 | { |
1c001dd2 CS |
214 | (void) CloseHandle (_cache_add_trigger); |
215 | DeleteCriticalSection (&_cache_write_access); | |
f449bfef RC |
216 | } |
217 | ||
1c001dd2 CS |
218 | /* This returns the process object to the caller already locked, that |
219 | * is, with the object's `access' critical region entered. Thus the | |
220 | * caller must unlock the object when it's finished with it (via | |
221 | * process::release ()). It must then not try to access the object | |
222 | * afterwards, except by going through this routine again, as it may | |
223 | * have been deleted once it has been unlocked. | |
224 | */ | |
225 | class process * | |
8d8f4036 | 226 | process_cache::process (const pid_t cygpid, const DWORD winpid) |
f449bfef | 227 | { |
1c001dd2 CS |
228 | /* TODO: make this more granular, so a search doesn't involve the |
229 | * write lock. | |
230 | */ | |
231 | EnterCriticalSection (&_cache_write_access); | |
232 | class process *previous = NULL; | |
233 | class process *entry = find (winpid, &previous); | |
234 | ||
235 | if (!entry) | |
f449bfef | 236 | { |
2d015bd6 | 237 | if (_processes_count >= _max_process_count) |
1c001dd2 CS |
238 | { |
239 | LeaveCriticalSection (&_cache_write_access); | |
240 | system_printf (("process limit (%d processes) reached; " | |
681bb2f7 | 241 | "new connection refused for %d(%u)"), |
2d015bd6 | 242 | _max_process_count, cygpid, winpid); |
1c001dd2 CS |
243 | return NULL; |
244 | } | |
245 | ||
8d8f4036 | 246 | entry = new class process (cygpid, winpid); |
1c001dd2 CS |
247 | if (!entry->is_active ()) |
248 | { | |
249 | LeaveCriticalSection (&_cache_write_access); | |
282113ba | 250 | delete entry; |
1c001dd2 CS |
251 | return NULL; |
252 | } | |
253 | ||
254 | if (previous) | |
255 | { | |
256 | entry->_next = previous->_next; | |
257 | previous->_next = entry; | |
258 | } | |
259 | else | |
260 | { | |
261 | entry->_next = _processes_head; | |
262 | _processes_head = entry; | |
263 | } | |
264 | ||
265 | _processes_count += 1; | |
266 | SetEvent (_cache_add_trigger); | |
f449bfef | 267 | } |
1c001dd2 | 268 | |
1f8b3049 | 269 | entry->hold (); // To be released by the caller. |
1c001dd2 CS |
270 | LeaveCriticalSection (&_cache_write_access); |
271 | assert (entry); | |
272 | assert (entry->_winpid == winpid); | |
273 | return entry; | |
f449bfef RC |
274 | } |
275 | ||
2d015bd6 CV |
276 | struct pcache_wait_t |
277 | { | |
278 | size_t index; | |
279 | size_t count; | |
280 | HANDLE *hdls; | |
281 | }; | |
282 | ||
283 | static DWORD WINAPI | |
284 | pcache_wait_thread (const LPVOID param) | |
285 | { | |
286 | pcache_wait_t *p = (pcache_wait_t *) param; | |
287 | ||
288 | DWORD rc = WaitForMultipleObjects (p->count, p->hdls, FALSE, INFINITE); | |
289 | ExitThread (rc == WAIT_FAILED ? rc : rc + p->index); | |
290 | } | |
291 | ||
f449bfef | 292 | void |
1c001dd2 | 293 | process_cache::wait_for_processes (const HANDLE interrupt_event) |
f449bfef | 294 | { |
1c001dd2 | 295 | // Update `_wait_array' with handles of all current processes. |
2d015bd6 | 296 | size_t idx; |
1c001dd2 CS |
297 | const size_t count = sync_wait_array (interrupt_event); |
298 | ||
299 | debug_printf ("waiting on %u objects in total (%u processes)", | |
300 | count, _processes_count); | |
301 | ||
2d015bd6 | 302 | DWORD rc = WAIT_FAILED; |
1c001dd2 | 303 | |
2d015bd6 | 304 | if (count <= 64) |
1c001dd2 | 305 | { |
2d015bd6 CV |
306 | /* If count <= 64, a single WaitForMultipleObjects is sufficient and |
307 | we can simply wait in the main thread. */ | |
308 | rc = WaitForMultipleObjects (count, _wait_array, FALSE, INFINITE); | |
309 | if (rc == WAIT_FAILED) | |
310 | { | |
681bb2f7 | 311 | system_printf ("could not wait on the process handles, error = %u", |
2d015bd6 CV |
312 | GetLastError ()); |
313 | abort (); | |
314 | } | |
1c001dd2 | 315 | } |
2d015bd6 CV |
316 | else |
317 | { | |
318 | /* If count > 64 we have to create sub-threads which wait for the | |
319 | actual wait objects and the main thread waits for the termination | |
320 | of one of the threads. */ | |
321 | HANDLE main_wait_array[5] = { NULL }; | |
322 | DWORD mcount = 0; | |
1c001dd2 | 323 | |
2d015bd6 CV |
324 | for (idx = 0; idx < count; idx += 64) |
325 | { | |
326 | pcache_wait_t p = { idx, min (count - idx, 64), _wait_array + idx }; | |
327 | main_wait_array[mcount++] = CreateThread (NULL, 0, pcache_wait_thread, | |
328 | &p, 0, NULL); | |
329 | } | |
1c001dd2 | 330 | |
2d015bd6 CV |
331 | rc = WaitForMultipleObjects (mcount, main_wait_array, FALSE, INFINITE); |
332 | if (rc == WAIT_FAILED) | |
333 | { | |
681bb2f7 | 334 | system_printf ("could not wait on the process handles, error = %u", |
2d015bd6 CV |
335 | GetLastError ()); |
336 | abort (); | |
337 | } | |
338 | ||
339 | /* Check for error condition on signalled sub-thread. */ | |
340 | GetExitCodeThread (main_wait_array[rc], &rc); | |
341 | if (rc == WAIT_FAILED) | |
342 | { | |
681bb2f7 | 343 | system_printf ("could not wait on the process handles, error = %u", |
2d015bd6 CV |
344 | GetLastError ()); |
345 | abort (); | |
346 | } | |
347 | ||
348 | /* Wake up all waiting threads. _cache_add_trigger gets reset | |
349 | in sync_wait_array again. */ | |
350 | SetEvent (_cache_add_trigger); | |
351 | WaitForMultipleObjects (mcount, main_wait_array, TRUE, INFINITE); | |
352 | for (idx = 0; idx < mcount; idx++) | |
353 | CloseHandle (main_wait_array[idx]); | |
f449bfef | 354 | } |
1c001dd2 | 355 | |
2d015bd6 CV |
356 | /* Tell all processes the bad news. This one formerly only checked |
357 | processes beginning with the index of the signalled process, but | |
358 | this can result in processes which are signalled but never removed | |
359 | under heavy load conditions. */ | |
360 | for (idx = 0; idx < count; idx++) | |
361 | if (_process_array[idx]) | |
362 | check_and_remove_process (idx); | |
f449bfef RC |
363 | } |
364 | ||
1c001dd2 CS |
365 | /* |
366 | * process_cache::sync_wait_array () | |
367 | * | |
368 | * Fill-in the wait array with the handles that the cache needs to wait on. | |
369 | * These handles are: | |
370 | * - the process_process_param's interrupt event | |
371 | * - the process_cache's cache_add_trigger event | |
372 | * - the handle for each live process in the cache. | |
373 | * | |
374 | * Return value: the number of live handles in the array. | |
375 | */ | |
376 | ||
377 | size_t | |
378 | process_cache::sync_wait_array (const HANDLE interrupt_event) | |
f449bfef | 379 | { |
1c001dd2 | 380 | assert (this); |
1c001dd2 CS |
381 | assert (interrupt_event && interrupt_event != INVALID_HANDLE_VALUE); |
382 | ||
2d015bd6 CV |
383 | /* Always reset _cache_add_trigger before filling up the array again. */ |
384 | ResetEvent (_cache_add_trigger); | |
1c001dd2 | 385 | |
2d015bd6 | 386 | EnterCriticalSection (&_cache_write_access); |
1c001dd2 CS |
387 | |
388 | size_t index = 0; | |
389 | ||
390 | for (class process *ptr = _processes_head; ptr; ptr = ptr->_next) | |
f449bfef | 391 | { |
1c001dd2 CS |
392 | assert (ptr->_hProcess && ptr->_hProcess != INVALID_HANDLE_VALUE); |
393 | assert (ptr->is_active ()); | |
394 | ||
395 | _wait_array[index] = ptr->handle (); | |
396 | _process_array[index++] = ptr; | |
397 | ||
2d015bd6 CV |
398 | if (!ptr->_next || index % 64 == 62) |
399 | { | |
400 | /* Added at the end of each thread's array part for efficiency. */ | |
401 | _wait_array[index] = interrupt_event; | |
402 | _process_array[index++] = NULL; | |
403 | _wait_array[index] = _cache_add_trigger; | |
404 | _process_array[index++] = NULL; | |
405 | } | |
f449bfef | 406 | } |
1c001dd2 | 407 | |
2d015bd6 CV |
408 | if (!index) |
409 | { | |
410 | /* To get at least *something* to wait for. */ | |
411 | _wait_array[index] = interrupt_event; | |
412 | _process_array[index++] = NULL; | |
413 | _wait_array[index] = _cache_add_trigger; | |
414 | _process_array[index++] = NULL; | |
415 | } | |
1c001dd2 CS |
416 | |
417 | assert (index <= elements (_wait_array)); | |
418 | ||
419 | LeaveCriticalSection (&_cache_write_access); | |
420 | ||
421 | return index; | |
f449bfef RC |
422 | } |
423 | ||
f449bfef | 424 | void |
1c001dd2 | 425 | process_cache::check_and_remove_process (const size_t index) |
f449bfef | 426 | { |
1c001dd2 CS |
427 | assert (this); |
428 | assert (index < elements (_wait_array) - SPECIALS_COUNT); | |
429 | ||
430 | class process *const process = _process_array[index]; | |
431 | ||
432 | assert (process); | |
433 | assert (process->handle () == _wait_array[index]); | |
434 | ||
435 | if (process->check_exit_code () == STILL_ACTIVE) | |
436 | return; | |
437 | ||
681bb2f7 | 438 | debug_printf ("process %d(%u) has left the building ($? = %u)", |
1c001dd2 CS |
439 | process->_cygpid, process->_winpid, process->_exit_status); |
440 | ||
441 | /* Unlink the process object from the process list. */ | |
442 | ||
443 | EnterCriticalSection (&_cache_write_access); | |
444 | ||
445 | class process *previous = NULL; | |
446 | ||
447 | const class process *const tmp = find (process->_winpid, &previous); | |
448 | ||
449 | assert (tmp == process); | |
450 | assert (previous ? previous->_next == process : _processes_head == process); | |
451 | ||
452 | if (previous) | |
453 | previous->_next = process->_next; | |
454 | else | |
455 | _processes_head = process->_next; | |
456 | ||
457 | _processes_count -= 1; | |
458 | LeaveCriticalSection (&_cache_write_access); | |
459 | ||
460 | /* Schedule any cleanup tasks for this process. */ | |
282113ba | 461 | _queue.add (new process_cleanup (process)); |
f449bfef RC |
462 | } |
463 | ||
1c001dd2 CS |
464 | class process * |
465 | process_cache::find (const DWORD winpid, class process **previous) | |
f449bfef | 466 | { |
1c001dd2 CS |
467 | if (previous) |
468 | *previous = NULL; | |
469 | ||
470 | for (class process *ptr = _processes_head; ptr; ptr = ptr->_next) | |
471 | if (ptr->_winpid == winpid) | |
472 | return ptr; | |
473 | else if (ptr->_winpid > winpid) // The list is sorted by winpid. | |
474 | return NULL; | |
475 | else if (previous) | |
476 | *previous = ptr; | |
477 | ||
478 | return NULL; | |
f449bfef | 479 | } |
1c001dd2 | 480 | |
8d8f4036 CV |
481 | void |
482 | thread::dup_signal_arrived () | |
483 | { | |
484 | if (ipcblk && ipcblk->signal_arrived | |
485 | && !DuplicateHandle (client->handle (), ipcblk->signal_arrived, | |
486 | GetCurrentProcess (), &ipcblk->signal_arrived, | |
487 | 0, FALSE, DUPLICATE_SAME_ACCESS)) | |
488 | { | |
489 | system_printf ("error duplicating thread's signal_arrived " | |
490 | "to server (%u)", GetLastError ()); | |
491 | ipcblk->signal_arrived = NULL; | |
492 | } | |
493 | } | |
494 | ||
495 | void | |
496 | thread::close_signal_arrived () | |
497 | { | |
498 | if (ipcblk && ipcblk->signal_arrived) | |
499 | CloseHandle (ipcblk->signal_arrived); | |
500 | } | |
501 | ||
1c001dd2 | 502 | /*****************************************************************************/ |
1dcd520b | 503 | #endif /* __OUTSIDE_CYGWIN__ */ |