Mercurial > sdl-ios-xcode
annotate src/thread/generic/SDL_syssem.c @ 571:8e3ce997621c
Date: Thu, 16 Jan 2003 13:48:31 +0200
From: "Mike Gorchak"
Subject: All QNX patches
whole patches concerning QNX. Almost all code has been rewritten by Julian
and me. Added initial support for hw overlays in QNX and many many others
fixes.
P.S. This patches has been reviewed by Dave Rempel from QSSL and included in
SDL 1.2.5 distribution, which coming on 3rd party CD for newest 6.2.1
version of QNX, which will be available soon.
| author | Sam Lantinga <slouken@libsdl.org> |
|---|---|
| date | Mon, 20 Jan 2003 01:38:37 +0000 |
| parents | f6ffac90895c |
| children | b8d311d90021 |
| rev | line source |
|---|---|
| 0 | 1 /* |
| 2 SDL - Simple DirectMedia Layer | |
|
297
f6ffac90895c
Updated copyright information for 2002
Sam Lantinga <slouken@libsdl.org>
parents:
252
diff
changeset
|
3 Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002 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
e8157fcb3114
Updated the source with the correct e-mail address
Sam Lantinga <slouken@libsdl.org>
parents:
0
diff
changeset
|
20 slouken@libsdl.org |
| 0 | 21 */ |
| 22 | |
| 23 #ifdef SAVE_RCSID | |
| 24 static char rcsid = | |
| 25 "@(#) $Id$"; | |
| 26 #endif | |
| 27 | |
| 28 /* An implementation of semaphores using mutexes and condition variables */ | |
| 29 | |
| 30 #include <stdlib.h> | |
| 31 | |
| 32 #include "SDL_error.h" | |
| 33 #include "SDL_timer.h" | |
| 34 #include "SDL_thread.h" | |
| 35 #include "SDL_systhread_c.h" | |
| 36 | |
| 37 | |
| 38 #ifdef DISABLE_THREADS | |
| 39 | |
| 40 SDL_sem *SDL_CreateSemaphore(Uint32 initial_value) | |
| 41 { | |
| 42 SDL_SetError("SDL not configured with thread support"); | |
| 43 return (SDL_sem *)0; | |
| 44 } | |
| 45 | |
| 46 void SDL_DestroySemaphore(SDL_sem *sem) | |
| 47 { | |
| 48 return; | |
| 49 } | |
| 50 | |
| 51 int SDL_SemTryWait(SDL_sem *sem) | |
| 52 { | |
| 53 SDL_SetError("SDL not configured with thread support"); | |
| 54 return -1; | |
| 55 } | |
| 56 | |
| 57 int SDL_SemWaitTimeout(SDL_sem *sem, Uint32 timeout) | |
| 58 { | |
| 59 SDL_SetError("SDL not configured with thread support"); | |
| 60 return -1; | |
| 61 } | |
| 62 | |
| 63 int SDL_SemWait(SDL_sem *sem) | |
| 64 { | |
| 65 SDL_SetError("SDL not configured with thread support"); | |
| 66 return -1; | |
| 67 } | |
| 68 | |
| 69 Uint32 SDL_SemValue(SDL_sem *sem) | |
| 70 { | |
| 71 return 0; | |
| 72 } | |
| 73 | |
| 74 int SDL_SemPost(SDL_sem *sem) | |
| 75 { | |
| 76 SDL_SetError("SDL not configured with thread support"); | |
| 77 return -1; | |
| 78 } | |
| 79 | |
| 80 #else | |
| 81 | |
| 82 struct SDL_semaphore | |
| 83 { | |
| 84 Uint32 count; | |
| 85 Uint32 waiters_count; | |
| 86 SDL_mutex *count_lock; | |
| 87 SDL_cond *count_nonzero; | |
| 88 }; | |
| 89 | |
| 90 SDL_sem *SDL_CreateSemaphore(Uint32 initial_value) | |
| 91 { | |
| 92 SDL_sem *sem; | |
| 93 | |
| 94 sem = (SDL_sem *)malloc(sizeof(*sem)); | |
| 95 if ( ! sem ) { | |
| 96 SDL_OutOfMemory(); | |
| 97 return(0); | |
| 98 } | |
| 99 sem->count = initial_value; | |
| 100 sem->waiters_count = 0; | |
| 101 | |
| 102 sem->count_lock = SDL_CreateMutex(); | |
| 103 sem->count_nonzero = SDL_CreateCond(); | |
| 104 if ( ! sem->count_lock || ! sem->count_nonzero ) { | |
| 105 SDL_DestroySemaphore(sem); | |
| 106 return(0); | |
| 107 } | |
| 108 | |
| 109 return(sem); | |
| 110 } | |
| 111 | |
| 112 /* WARNING: | |
| 113 You cannot call this function when another thread is using the semaphore. | |
| 114 */ | |
| 115 void SDL_DestroySemaphore(SDL_sem *sem) | |
| 116 { | |
| 117 if ( sem ) { | |
| 118 sem->count = 0xFFFFFFFF; | |
| 119 while ( sem->waiters_count > 0) { | |
| 120 SDL_CondSignal(sem->count_nonzero); | |
| 121 SDL_Delay(10); | |
| 122 } | |
| 123 SDL_DestroyCond(sem->count_nonzero); | |
| 124 SDL_mutexP(sem->count_lock); | |
| 125 SDL_mutexV(sem->count_lock); | |
| 126 SDL_DestroyMutex(sem->count_lock); | |
| 127 free(sem); | |
| 128 } | |
| 129 } | |
| 130 | |
| 131 int SDL_SemTryWait(SDL_sem *sem) | |
| 132 { | |
| 133 int retval; | |
| 134 | |
| 135 if ( ! sem ) { | |
| 136 SDL_SetError("Passed a NULL semaphore"); | |
| 137 return -1; | |
| 138 } | |
| 139 | |
| 140 retval = SDL_MUTEX_TIMEDOUT; | |
| 141 SDL_LockMutex(sem->count_lock); | |
| 142 if ( sem->count > 0 ) { | |
| 143 --sem->count; | |
| 144 retval = 0; | |
| 145 } | |
| 146 SDL_UnlockMutex(sem->count_lock); | |
| 147 | |
| 148 return retval; | |
| 149 } | |
| 150 | |
| 151 int SDL_SemWaitTimeout(SDL_sem *sem, Uint32 timeout) | |
| 152 { | |
| 153 int retval; | |
| 154 | |
| 155 if ( ! sem ) { | |
| 156 SDL_SetError("Passed a NULL semaphore"); | |
| 157 return -1; | |
| 158 } | |
| 159 | |
| 160 /* A timeout of 0 is an easy case */ | |
| 161 if ( timeout == 0 ) { | |
| 162 return SDL_SemTryWait(sem); | |
| 163 } | |
| 164 | |
| 165 SDL_LockMutex(sem->count_lock); | |
| 166 ++sem->waiters_count; | |
| 167 retval = 0; | |
| 168 while ( (sem->count == 0) && (retval != SDL_MUTEX_TIMEDOUT) ) { | |
| 169 retval = SDL_CondWaitTimeout(sem->count_nonzero, | |
| 170 sem->count_lock, timeout); | |
| 171 } | |
| 172 --sem->waiters_count; | |
| 173 --sem->count; | |
| 174 SDL_UnlockMutex(sem->count_lock); | |
| 175 | |
| 176 return retval; | |
| 177 } | |
| 178 | |
| 179 int SDL_SemWait(SDL_sem *sem) | |
| 180 { | |
| 181 return SDL_SemWaitTimeout(sem, SDL_MUTEX_MAXWAIT); | |
| 182 } | |
| 183 | |
| 184 Uint32 SDL_SemValue(SDL_sem *sem) | |
| 185 { | |
| 186 Uint32 value; | |
| 187 | |
| 188 value = 0; | |
| 189 if ( sem ) { | |
| 190 SDL_LockMutex(sem->count_lock); | |
| 191 value = sem->count; | |
| 192 SDL_UnlockMutex(sem->count_lock); | |
| 193 } | |
| 194 return value; | |
| 195 } | |
| 196 | |
| 197 int SDL_SemPost(SDL_sem *sem) | |
| 198 { | |
| 199 if ( ! sem ) { | |
| 200 SDL_SetError("Passed a NULL semaphore"); | |
| 201 return -1; | |
| 202 } | |
| 203 | |
| 204 SDL_LockMutex(sem->count_lock); | |
| 205 if ( sem->waiters_count > 0 ) { | |
| 206 SDL_CondSignal(sem->count_nonzero); | |
| 207 } | |
| 208 ++sem->count; | |
| 209 SDL_UnlockMutex(sem->count_lock); | |
| 210 | |
| 211 return 0; | |
| 212 } | |
| 213 | |
| 214 #endif /* DISABLE_THREADS */ |