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annotate src/thread/linux/SDL_sysmutex.c @ 1066:671bbd773c8a
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| author | Patrice Mandin <patmandin@gmail.com> |
|---|---|
| date | Thu, 02 Jun 2005 22:02:18 +0000 |
| parents | b8d311d90021 |
| children | c9b51268668f |
| rev | line source |
|---|---|
| 0 | 1 /* |
| 2 SDL - Simple DirectMedia Layer | |
|
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b8d311d90021
Updated copyright information for 2004 (Happy New Year!)
Sam Lantinga <slouken@libsdl.org>
parents:
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3 Copyright (C) 1997-2004 Sam Lantinga |
| 0 | 4 |
| 5 This library is free software; you can redistribute it and/or | |
| 6 modify it under the terms of the GNU Library General Public | |
| 7 License as published by the Free Software Foundation; either | |
| 8 version 2 of the License, or (at your option) any later version. | |
| 9 | |
| 10 This library is distributed in the hope that it will be useful, | |
| 11 but WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
| 13 Library General Public License for more details. | |
| 14 | |
| 15 You should have received a copy of the GNU Library General Public | |
| 16 License along with this library; if not, write to the Free | |
| 17 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
| 18 | |
| 19 Sam Lantinga | |
|
252
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Updated the source with the correct e-mail address
Sam Lantinga <slouken@libsdl.org>
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20 slouken@libsdl.org |
| 0 | 21 */ |
| 22 | |
| 23 #ifdef SAVE_RCSID | |
| 24 static char rcsid = | |
| 25 "@(#) $Id$"; | |
| 26 #endif | |
| 27 | |
| 28 #ifdef linux | |
| 29 /* Look to see if glibc is available, and if so, what version */ | |
| 30 #include <features.h> | |
| 31 | |
| 32 #if (__GLIBC__ == 2) && (__GLIBC_MINOR__ == 0) | |
| 33 #warning Working around a bug in glibc 2.0 pthreads | |
| 34 #undef SDL_USE_PTHREADS | |
| 35 /* The bug is actually a problem where threads are suspended, but don't | |
| 36 wake up when the thread manager sends them a signal. This is a problem | |
| 37 with thread creation too, but it happens less often. :-/ | |
| 38 We avoid this by using System V IPC for mutexes. | |
| 39 */ | |
| 40 #endif /* glibc 2.0 */ | |
| 41 #endif /* linux */ | |
| 42 | |
| 43 #ifdef SDL_USE_PTHREADS | |
| 44 | |
| 45 #include <stdlib.h> | |
| 46 #include <stdio.h> | |
| 47 #include <pthread.h> | |
| 48 | |
| 49 #include "SDL_error.h" | |
| 50 #include "SDL_thread.h" | |
| 51 | |
| 52 | |
| 53 struct SDL_mutex { | |
| 54 pthread_mutex_t id; | |
| 55 #ifdef PTHREAD_NO_RECURSIVE_MUTEX | |
| 56 int recursive; | |
| 57 pthread_t owner; | |
| 58 #endif | |
| 59 }; | |
| 60 | |
| 61 SDL_mutex *SDL_CreateMutex (void) | |
| 62 { | |
| 63 SDL_mutex *mutex; | |
| 64 pthread_mutexattr_t attr; | |
| 65 | |
| 66 /* Allocate the structure */ | |
| 67 mutex = (SDL_mutex *)calloc(1, sizeof(*mutex)); | |
| 68 if ( mutex ) { | |
| 69 pthread_mutexattr_init(&attr); | |
| 70 #ifdef PTHREAD_NO_RECURSIVE_MUTEX | |
| 71 /* No extra attributes necessary */ | |
| 72 #else | |
| 73 #ifdef linux | |
| 74 pthread_mutexattr_setkind_np(&attr, PTHREAD_MUTEX_RECURSIVE_NP); | |
| 75 #else | |
| 76 pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE); | |
| 77 #endif | |
| 78 #endif /* PTHREAD_NO_RECURSIVE_MUTEX */ | |
| 79 if ( pthread_mutex_init(&mutex->id, &attr) != 0 ) { | |
| 80 SDL_SetError("pthread_mutex_init() failed"); | |
| 81 free(mutex); | |
| 82 mutex = NULL; | |
| 83 } | |
| 84 } else { | |
| 85 SDL_OutOfMemory(); | |
| 86 } | |
| 87 return(mutex); | |
| 88 } | |
| 89 | |
| 90 void SDL_DestroyMutex(SDL_mutex *mutex) | |
| 91 { | |
| 92 if ( mutex ) { | |
| 93 pthread_mutex_destroy(&mutex->id); | |
| 94 free(mutex); | |
| 95 } | |
| 96 } | |
| 97 | |
| 98 /* Lock the mutex */ | |
| 99 int SDL_mutexP(SDL_mutex *mutex) | |
| 100 { | |
| 101 int retval; | |
| 102 #ifdef PTHREAD_NO_RECURSIVE_MUTEX | |
| 103 pthread_t this_thread; | |
| 104 #endif | |
| 105 | |
| 106 if ( mutex == NULL ) { | |
| 107 SDL_SetError("Passed a NULL mutex"); | |
| 108 return -1; | |
| 109 } | |
| 110 | |
| 111 retval = 0; | |
| 112 #ifdef PTHREAD_NO_RECURSIVE_MUTEX | |
| 113 this_thread = pthread_self(); | |
| 114 if ( mutex->owner == this_thread ) { | |
| 115 ++mutex->recursive; | |
| 116 } else { | |
| 117 /* The order of operations is important. | |
| 118 We set the locking thread id after we obtain the lock | |
| 119 so unlocks from other threads will fail. | |
| 120 */ | |
| 121 if ( pthread_mutex_lock(&mutex->id) == 0 ) { | |
| 122 mutex->owner = this_thread; | |
| 123 mutex->recursive = 0; | |
| 124 } else { | |
| 125 SDL_SetError("pthread_mutex_lock() failed"); | |
| 126 retval = -1; | |
| 127 } | |
| 128 } | |
| 129 #else | |
| 130 if ( pthread_mutex_lock(&mutex->id) < 0 ) { | |
| 131 SDL_SetError("pthread_mutex_lock() failed"); | |
| 132 retval = -1; | |
| 133 } | |
| 134 #endif | |
| 135 return retval; | |
| 136 } | |
| 137 | |
| 138 int SDL_mutexV(SDL_mutex *mutex) | |
| 139 { | |
| 140 int retval; | |
| 141 | |
| 142 if ( mutex == NULL ) { | |
| 143 SDL_SetError("Passed a NULL mutex"); | |
| 144 return -1; | |
| 145 } | |
| 146 | |
| 147 retval = 0; | |
| 148 #ifdef PTHREAD_NO_RECURSIVE_MUTEX | |
| 149 /* We can only unlock the mutex if we own it */ | |
| 150 if ( pthread_self() == mutex->owner ) { | |
| 151 if ( mutex->recursive ) { | |
| 152 --mutex->recursive; | |
| 153 } else { | |
| 154 /* The order of operations is important. | |
| 155 First reset the owner so another thread doesn't lock | |
| 156 the mutex and set the ownership before we reset it, | |
| 157 then release the lock semaphore. | |
| 158 */ | |
| 159 mutex->owner = 0; | |
| 160 pthread_mutex_unlock(&mutex->id); | |
| 161 } | |
| 162 } else { | |
| 163 SDL_SetError("mutex not owned by this thread"); | |
| 164 retval = -1; | |
| 165 } | |
| 166 | |
| 167 #else | |
| 168 if ( pthread_mutex_unlock(&mutex->id) < 0 ) { | |
| 169 SDL_SetError("pthread_mutex_unlock() failed"); | |
| 170 retval = -1; | |
| 171 } | |
| 172 #endif /* PTHREAD_NO_RECURSIVE_MUTEX */ | |
| 173 | |
| 174 return retval; | |
| 175 } | |
| 176 | |
| 177 #else /* Use semaphore implementation */ | |
| 178 | |
| 179 #include "generic/SDL_sysmutex.c" | |
| 180 | |
| 181 #endif /* SDL_USE_PTHREADS */ |