Mercurial > sdl-ios-xcode
annotate src/thread/generic/SDL_syssem.c @ 1358:c71e05b4dc2e
More header massaging... works great on Windows. ;-)
| author | Sam Lantinga <slouken@libsdl.org> |
|---|---|
| date | Fri, 10 Feb 2006 06:48:43 +0000 |
| parents | 604d73db6802 |
| children | 19418e4422cb |
| rev | line source |
|---|---|
| 0 | 1 /* |
| 2 SDL - Simple DirectMedia Layer | |
|
1312
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Updated copyright information and removed rcs id lines (problematic in branch merges)
Sam Lantinga <slouken@libsdl.org>
parents:
769
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changeset
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3 Copyright (C) 1997-2006 Sam Lantinga |
| 0 | 4 |
| 5 This library is free software; you can redistribute it and/or | |
|
1312
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Updated copyright information and removed rcs id lines (problematic in branch merges)
Sam Lantinga <slouken@libsdl.org>
parents:
769
diff
changeset
|
6 modify it under the terms of the GNU Lesser General Public |
| 0 | 7 License as published by the Free Software Foundation; either |
|
1312
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Updated copyright information and removed rcs id lines (problematic in branch merges)
Sam Lantinga <slouken@libsdl.org>
parents:
769
diff
changeset
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8 version 2.1 of the License, or (at your option) any later version. |
| 0 | 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 | |
|
1312
c9b51268668f
Updated copyright information and removed rcs id lines (problematic in branch merges)
Sam Lantinga <slouken@libsdl.org>
parents:
769
diff
changeset
|
13 Lesser General Public License for more details. |
| 0 | 14 |
|
1312
c9b51268668f
Updated copyright information and removed rcs id lines (problematic in branch merges)
Sam Lantinga <slouken@libsdl.org>
parents:
769
diff
changeset
|
15 You should have received a copy of the GNU Lesser General Public |
|
c9b51268668f
Updated copyright information and removed rcs id lines (problematic in branch merges)
Sam Lantinga <slouken@libsdl.org>
parents:
769
diff
changeset
|
16 License along with this library; if not, write to the Free Software |
|
c9b51268668f
Updated copyright information and removed rcs id lines (problematic in branch merges)
Sam Lantinga <slouken@libsdl.org>
parents:
769
diff
changeset
|
17 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA |
| 0 | 18 |
| 19 Sam Lantinga | |
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252
e8157fcb3114
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 /* An implementation of semaphores using mutexes and condition variables */ | |
| 24 | |
| 25 #include "SDL_timer.h" | |
| 26 #include "SDL_thread.h" | |
| 27 #include "SDL_systhread_c.h" | |
| 28 | |
| 29 | |
| 30 #ifdef DISABLE_THREADS | |
| 31 | |
| 32 SDL_sem *SDL_CreateSemaphore(Uint32 initial_value) | |
| 33 { | |
| 34 SDL_SetError("SDL not configured with thread support"); | |
| 35 return (SDL_sem *)0; | |
| 36 } | |
| 37 | |
| 38 void SDL_DestroySemaphore(SDL_sem *sem) | |
| 39 { | |
| 40 return; | |
| 41 } | |
| 42 | |
| 43 int SDL_SemTryWait(SDL_sem *sem) | |
| 44 { | |
| 45 SDL_SetError("SDL not configured with thread support"); | |
| 46 return -1; | |
| 47 } | |
| 48 | |
| 49 int SDL_SemWaitTimeout(SDL_sem *sem, Uint32 timeout) | |
| 50 { | |
| 51 SDL_SetError("SDL not configured with thread support"); | |
| 52 return -1; | |
| 53 } | |
| 54 | |
| 55 int SDL_SemWait(SDL_sem *sem) | |
| 56 { | |
| 57 SDL_SetError("SDL not configured with thread support"); | |
| 58 return -1; | |
| 59 } | |
| 60 | |
| 61 Uint32 SDL_SemValue(SDL_sem *sem) | |
| 62 { | |
| 63 return 0; | |
| 64 } | |
| 65 | |
| 66 int SDL_SemPost(SDL_sem *sem) | |
| 67 { | |
| 68 SDL_SetError("SDL not configured with thread support"); | |
| 69 return -1; | |
| 70 } | |
| 71 | |
| 72 #else | |
| 73 | |
| 74 struct SDL_semaphore | |
| 75 { | |
| 76 Uint32 count; | |
| 77 Uint32 waiters_count; | |
| 78 SDL_mutex *count_lock; | |
| 79 SDL_cond *count_nonzero; | |
| 80 }; | |
| 81 | |
| 82 SDL_sem *SDL_CreateSemaphore(Uint32 initial_value) | |
| 83 { | |
| 84 SDL_sem *sem; | |
| 85 | |
|
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parents:
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86 sem = (SDL_sem *)SDL_malloc(sizeof(*sem)); |
| 0 | 87 if ( ! sem ) { |
| 88 SDL_OutOfMemory(); | |
| 89 return(0); | |
| 90 } | |
| 91 sem->count = initial_value; | |
| 92 sem->waiters_count = 0; | |
| 93 | |
| 94 sem->count_lock = SDL_CreateMutex(); | |
| 95 sem->count_nonzero = SDL_CreateCond(); | |
| 96 if ( ! sem->count_lock || ! sem->count_nonzero ) { | |
| 97 SDL_DestroySemaphore(sem); | |
| 98 return(0); | |
| 99 } | |
| 100 | |
| 101 return(sem); | |
| 102 } | |
| 103 | |
| 104 /* WARNING: | |
| 105 You cannot call this function when another thread is using the semaphore. | |
| 106 */ | |
| 107 void SDL_DestroySemaphore(SDL_sem *sem) | |
| 108 { | |
| 109 if ( sem ) { | |
| 110 sem->count = 0xFFFFFFFF; | |
| 111 while ( sem->waiters_count > 0) { | |
| 112 SDL_CondSignal(sem->count_nonzero); | |
| 113 SDL_Delay(10); | |
| 114 } | |
| 115 SDL_DestroyCond(sem->count_nonzero); | |
| 116 SDL_mutexP(sem->count_lock); | |
| 117 SDL_mutexV(sem->count_lock); | |
| 118 SDL_DestroyMutex(sem->count_lock); | |
|
1336
3692456e7b0f
Use SDL_ prefixed versions of C library functions.
Sam Lantinga <slouken@libsdl.org>
parents:
1330
diff
changeset
|
119 SDL_free(sem); |
| 0 | 120 } |
| 121 } | |
| 122 | |
| 123 int SDL_SemTryWait(SDL_sem *sem) | |
| 124 { | |
| 125 int retval; | |
| 126 | |
| 127 if ( ! sem ) { | |
| 128 SDL_SetError("Passed a NULL semaphore"); | |
| 129 return -1; | |
| 130 } | |
| 131 | |
| 132 retval = SDL_MUTEX_TIMEDOUT; | |
| 133 SDL_LockMutex(sem->count_lock); | |
| 134 if ( sem->count > 0 ) { | |
| 135 --sem->count; | |
| 136 retval = 0; | |
| 137 } | |
| 138 SDL_UnlockMutex(sem->count_lock); | |
| 139 | |
| 140 return retval; | |
| 141 } | |
| 142 | |
| 143 int SDL_SemWaitTimeout(SDL_sem *sem, Uint32 timeout) | |
| 144 { | |
| 145 int retval; | |
| 146 | |
| 147 if ( ! sem ) { | |
| 148 SDL_SetError("Passed a NULL semaphore"); | |
| 149 return -1; | |
| 150 } | |
| 151 | |
| 152 /* A timeout of 0 is an easy case */ | |
| 153 if ( timeout == 0 ) { | |
| 154 return SDL_SemTryWait(sem); | |
| 155 } | |
| 156 | |
| 157 SDL_LockMutex(sem->count_lock); | |
| 158 ++sem->waiters_count; | |
| 159 retval = 0; | |
| 160 while ( (sem->count == 0) && (retval != SDL_MUTEX_TIMEDOUT) ) { | |
| 161 retval = SDL_CondWaitTimeout(sem->count_nonzero, | |
| 162 sem->count_lock, timeout); | |
| 163 } | |
| 164 --sem->waiters_count; | |
| 165 --sem->count; | |
| 166 SDL_UnlockMutex(sem->count_lock); | |
| 167 | |
| 168 return retval; | |
| 169 } | |
| 170 | |
| 171 int SDL_SemWait(SDL_sem *sem) | |
| 172 { | |
| 173 return SDL_SemWaitTimeout(sem, SDL_MUTEX_MAXWAIT); | |
| 174 } | |
| 175 | |
| 176 Uint32 SDL_SemValue(SDL_sem *sem) | |
| 177 { | |
| 178 Uint32 value; | |
| 179 | |
| 180 value = 0; | |
| 181 if ( sem ) { | |
| 182 SDL_LockMutex(sem->count_lock); | |
| 183 value = sem->count; | |
| 184 SDL_UnlockMutex(sem->count_lock); | |
| 185 } | |
| 186 return value; | |
| 187 } | |
| 188 | |
| 189 int SDL_SemPost(SDL_sem *sem) | |
| 190 { | |
| 191 if ( ! sem ) { | |
| 192 SDL_SetError("Passed a NULL semaphore"); | |
| 193 return -1; | |
| 194 } | |
| 195 | |
| 196 SDL_LockMutex(sem->count_lock); | |
| 197 if ( sem->waiters_count > 0 ) { | |
| 198 SDL_CondSignal(sem->count_nonzero); | |
| 199 } | |
| 200 ++sem->count; | |
| 201 SDL_UnlockMutex(sem->count_lock); | |
| 202 | |
| 203 return 0; | |
| 204 } | |
| 205 | |
| 206 #endif /* DISABLE_THREADS */ |