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1 | /* Copyright (C) 1994, 1996 Free Software Foundation, Inc. | |
2 | This file is part of the GNU C Library. | |
3 | ||
4 | The GNU C Library is free software; you can redistribute it and/or | |
5 | modify it under the terms of the GNU Library General Public License as | |
6 | published by the Free Software Foundation; either version 2 of the | |
7 | License, or (at your option) any later version. | |
8 | ||
9 | The GNU C Library is distributed in the hope that it will be useful, | |
10 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
12 | Library General Public License for more details. | |
13 | ||
14 | You should have received a copy of the GNU Library General Public | |
15 | License along with the GNU C Library; see the file COPYING.LIB. If not, | |
16 | write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, | |
17 | Boston, MA 02111-1307, USA. */ | |
18 | ||
19 | #ifndef _LOCK_INTERN_H | |
20 | #define _LOCK_INTERN_H | |
21 | ||
22 | #include <machine-lock.h> | |
23 | ||
24 | #ifndef _EXTERN_INLINE | |
25 | #define _EXTERN_INLINE extern __inline | |
26 | #endif | |
27 | ||
28 | ||
29 | /* Initialize LOCK. */ | |
30 | ||
31 | _EXTERN_INLINE void | |
32 | __spin_lock_init (__spin_lock_t *__lock) | |
33 | { | |
34 | *__lock = __SPIN_LOCK_INITIALIZER; | |
35 | } | |
36 | ||
37 | ||
38 | /* Lock LOCK, blocking if we can't get it. */ | |
39 | extern void __spin_lock_solid (__spin_lock_t *__lock); | |
40 | ||
41 | /* Lock the spin lock LOCK. */ | |
42 | ||
43 | _EXTERN_INLINE void | |
44 | __spin_lock (__spin_lock_t *__lock) | |
45 | { | |
46 | if (! __spin_try_lock (__lock)) | |
47 | __spin_lock_solid (__lock); | |
48 | } | |
49 | \f | |
50 | /* Name space-clean internal interface to mutex locks. | |
51 | ||
52 | Code internal to the C library uses these functions to lock and unlock | |
53 | mutex locks. These locks are of type `struct mutex', defined in | |
54 | <cthreads.h>. The functions here are name space-clean. If the program | |
55 | is linked with the cthreads library, `__mutex_lock_solid' and | |
56 | `__mutex_unlock_solid' will invoke the corresponding cthreads functions | |
57 | to implement real mutex locks. If not, simple stub versions just use | |
58 | spin locks. */ | |
59 | ||
60 | ||
61 | /* Initialize the newly allocated mutex lock LOCK for further use. */ | |
62 | extern void __mutex_init (void *__lock); | |
63 | ||
64 | /* Lock LOCK, blocking if we can't get it. */ | |
65 | extern void __mutex_lock_solid (void *__lock); | |
66 | ||
67 | /* Finish unlocking LOCK, after the spin lock LOCK->held has already been | |
68 | unlocked. This function will wake up any thread waiting on LOCK. */ | |
69 | extern void __mutex_unlock_solid (void *__lock); | |
70 | ||
71 | /* Lock the mutex lock LOCK. */ | |
72 | ||
73 | _EXTERN_INLINE void | |
74 | __mutex_lock (void *__lock) | |
75 | { | |
76 | if (! __spin_try_lock ((__spin_lock_t *) __lock)) | |
77 | __mutex_lock_solid (__lock); | |
78 | } | |
79 | ||
80 | /* Unlock the mutex lock LOCK. */ | |
81 | ||
82 | _EXTERN_INLINE void | |
83 | __mutex_unlock (void *__lock) | |
84 | { | |
85 | __spin_unlock ((__spin_lock_t *) __lock); | |
86 | __mutex_unlock_solid (__lock); | |
87 | } | |
88 | ||
89 | ||
90 | _EXTERN_INLINE int | |
91 | __mutex_trylock (void *__lock) | |
92 | { | |
93 | return __spin_try_lock ((__spin_lock_t *) __lock); | |
94 | } | |
95 | ||
96 | #endif /* lock-intern.h */ |