Mercurial > sdl-ios-xcode
annotate src/thread/SDL_thread.c @ 255:dcb5e869f8b5
Updated Amiga port by Gabriele Greco
| author | Sam Lantinga <slouken@libsdl.org> |
|---|---|
| date | Sun, 16 Dec 2001 20:00:27 +0000 |
| parents | e8157fcb3114 |
| children | f6ffac90895c |
| rev | line source |
|---|---|
| 0 | 1 /* |
| 2 SDL - Simple DirectMedia Layer | |
| 3 Copyright (C) 1997, 1998, 1999, 2000, 2001 Sam Lantinga | |
| 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 | |
|
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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 #ifdef SAVE_RCSID | |
| 24 static char rcsid = | |
| 25 "@(#) $Id$"; | |
| 26 #endif | |
| 27 | |
| 28 /* System independent thread management routines for SDL */ | |
| 29 | |
| 30 #include <stdio.h> | |
| 31 #include <stdlib.h> | |
| 32 #include <string.h> | |
| 33 | |
| 34 #include "SDL_error.h" | |
| 35 #include "SDL_mutex.h" | |
| 36 #include "SDL_thread.h" | |
| 37 #include "SDL_thread_c.h" | |
| 38 #include "SDL_systhread.h" | |
| 39 | |
| 40 #define ARRAY_CHUNKSIZE 32 | |
| 41 /* The array of threads currently active in the application | |
| 42 (except the main thread) | |
| 43 The manipulation of an array here is safer than using a linked list. | |
| 44 */ | |
| 45 static int SDL_maxthreads = 0; | |
| 46 static int SDL_numthreads = 0; | |
| 47 static SDL_Thread **SDL_Threads = NULL; | |
| 48 static SDL_mutex *thread_lock = NULL; | |
| 49 int _creating_thread_lock = 0; | |
| 50 | |
| 51 int SDL_ThreadsInit(void) | |
| 52 { | |
| 53 int retval; | |
| 54 | |
| 55 retval = 0; | |
| 56 /* Set the thread lock creation flag so that we can reuse an | |
| 57 existing lock on the system - since this mutex never gets | |
| 58 destroyed (see SDL_ThreadsQuit()), we want to reuse it. | |
| 59 */ | |
| 60 _creating_thread_lock = 1; | |
| 61 thread_lock = SDL_CreateMutex(); | |
| 62 _creating_thread_lock = 0; | |
| 63 if ( thread_lock == NULL ) { | |
| 64 retval = -1; | |
| 65 } | |
| 66 return(retval); | |
| 67 } | |
| 68 | |
| 69 /* This should never be called... | |
| 70 If this is called by SDL_Quit(), we don't know whether or not we should | |
| 71 clean up threads here. If any threads are still running after this call, | |
| 72 they will no longer have access to any per-thread data. | |
| 73 */ | |
| 74 void SDL_ThreadsQuit() | |
| 75 { | |
| 76 SDL_mutex *mutex; | |
| 77 | |
| 78 mutex = thread_lock; | |
| 79 thread_lock = NULL; | |
| 80 if ( mutex != NULL ) { | |
| 81 SDL_DestroyMutex(mutex); | |
| 82 } | |
| 83 } | |
| 84 | |
| 85 /* Routines for manipulating the thread list */ | |
| 86 static void SDL_AddThread(SDL_Thread *thread) | |
| 87 { | |
| 88 SDL_Thread **threads; | |
| 89 | |
| 90 /* WARNING: | |
| 91 If the very first threads are created simultaneously, then | |
| 92 there could be a race condition causing memory corruption. | |
| 93 In practice, this isn't a problem because by definition there | |
| 94 is only one thread running the first time this is called. | |
| 95 */ | |
| 96 if ( thread_lock == NULL ) { | |
| 97 if ( SDL_ThreadsInit() < 0 ) { | |
| 98 return; | |
| 99 } | |
| 100 } | |
| 101 SDL_mutexP(thread_lock); | |
| 102 | |
| 103 /* Expand the list of threads, if necessary */ | |
| 104 #ifdef DEBUG_THREADS | |
| 105 printf("Adding thread (%d already - %d max)\n", | |
| 106 SDL_numthreads, SDL_maxthreads); | |
| 107 #endif | |
| 108 if ( SDL_numthreads == SDL_maxthreads ) { | |
| 109 threads=(SDL_Thread **)malloc((SDL_maxthreads+ARRAY_CHUNKSIZE)* | |
| 110 (sizeof *threads)); | |
| 111 if ( threads == NULL ) { | |
| 112 SDL_OutOfMemory(); | |
| 113 goto done; | |
| 114 } | |
| 115 memcpy(threads, SDL_Threads, SDL_numthreads*(sizeof *threads)); | |
| 116 SDL_maxthreads += ARRAY_CHUNKSIZE; | |
| 117 if ( SDL_Threads ) { | |
| 118 free(SDL_Threads); | |
| 119 } | |
| 120 SDL_Threads = threads; | |
| 121 } | |
| 122 SDL_Threads[SDL_numthreads++] = thread; | |
| 123 done: | |
| 124 SDL_mutexV(thread_lock); | |
| 125 } | |
| 126 | |
| 127 static void SDL_DelThread(SDL_Thread *thread) | |
| 128 { | |
| 129 int i; | |
| 130 | |
| 131 if ( thread_lock ) { | |
| 132 SDL_mutexP(thread_lock); | |
| 133 for ( i=0; i<SDL_numthreads; ++i ) { | |
| 134 if ( thread == SDL_Threads[i] ) { | |
| 135 break; | |
| 136 } | |
| 137 } | |
| 138 if ( i < SDL_numthreads ) { | |
| 139 --SDL_numthreads; | |
| 140 while ( i < SDL_numthreads ) { | |
| 141 SDL_Threads[i] = SDL_Threads[i+1]; | |
| 142 ++i; | |
| 143 } | |
| 144 #ifdef DEBUG_THREADS | |
| 145 printf("Deleting thread (%d left - %d max)\n", | |
| 146 SDL_numthreads, SDL_maxthreads); | |
| 147 #endif | |
| 148 } | |
| 149 SDL_mutexV(thread_lock); | |
| 150 } | |
| 151 } | |
| 152 | |
| 153 /* The default (non-thread-safe) global error variable */ | |
| 154 static SDL_error SDL_global_error; | |
| 155 | |
| 156 /* Routine to get the thread-specific error variable */ | |
| 157 SDL_error *SDL_GetErrBuf(void) | |
| 158 { | |
| 159 SDL_error *errbuf; | |
| 160 | |
| 161 errbuf = &SDL_global_error; | |
| 162 if ( SDL_Threads ) { | |
| 163 int i; | |
| 164 Uint32 this_thread; | |
| 165 | |
| 166 this_thread = SDL_ThreadID(); | |
| 167 SDL_mutexP(thread_lock); | |
| 168 for ( i=0; i<SDL_numthreads; ++i ) { | |
| 169 if ( this_thread == SDL_Threads[i]->threadid ) { | |
| 170 errbuf = &SDL_Threads[i]->errbuf; | |
| 171 break; | |
| 172 } | |
| 173 } | |
| 174 SDL_mutexV(thread_lock); | |
| 175 } | |
| 176 return(errbuf); | |
| 177 } | |
| 178 | |
| 179 | |
| 180 /* Arguments and callback to setup and run the user thread function */ | |
| 181 typedef struct { | |
| 182 int (*func)(void *); | |
| 183 void *data; | |
| 184 SDL_Thread *info; | |
| 185 SDL_sem *wait; | |
| 186 } thread_args; | |
| 187 | |
| 188 void SDL_RunThread(void *data) | |
| 189 { | |
| 190 thread_args *args; | |
| 191 int (*userfunc)(void *); | |
| 192 void *userdata; | |
| 193 int *statusloc; | |
| 194 | |
| 195 /* Perform any system-dependent setup | |
| 196 - this function cannot fail, and cannot use SDL_SetError() | |
| 197 */ | |
| 198 SDL_SYS_SetupThread(); | |
| 199 | |
| 200 /* Get the thread id */ | |
| 201 args = (thread_args *)data; | |
| 202 args->info->threadid = SDL_ThreadID(); | |
| 203 | |
| 204 /* Figure out what function to run */ | |
| 205 userfunc = args->func; | |
| 206 userdata = args->data; | |
| 207 statusloc = &args->info->status; | |
| 208 | |
| 209 /* Wake up the parent thread */ | |
| 210 SDL_SemPost(args->wait); | |
| 211 | |
| 212 /* Run the function */ | |
| 213 *statusloc = userfunc(userdata); | |
| 214 } | |
| 215 | |
| 216 SDL_Thread *SDL_CreateThread(int (*fn)(void *), void *data) | |
| 217 { | |
| 218 SDL_Thread *thread; | |
| 219 thread_args *args; | |
| 220 int ret; | |
| 221 | |
| 222 /* Allocate memory for the thread info structure */ | |
| 223 thread = (SDL_Thread *)malloc(sizeof(*thread)); | |
| 224 if ( thread == NULL ) { | |
| 225 SDL_OutOfMemory(); | |
| 226 return(NULL); | |
| 227 } | |
| 228 memset(thread, 0, (sizeof *thread)); | |
| 229 thread->status = -1; | |
| 230 | |
| 231 /* Set up the arguments for the thread */ | |
| 232 args = (thread_args *)malloc(sizeof(*args)); | |
| 233 if ( args == NULL ) { | |
| 234 SDL_OutOfMemory(); | |
| 235 free(thread); | |
| 236 return(NULL); | |
| 237 } | |
| 238 args->func = fn; | |
| 239 args->data = data; | |
| 240 args->info = thread; | |
| 241 args->wait = SDL_CreateSemaphore(0); | |
| 242 if ( args->wait == NULL ) { | |
| 243 free(thread); | |
| 244 free(args); | |
| 245 return(NULL); | |
| 246 } | |
| 247 | |
| 248 /* Add the thread to the list of available threads */ | |
| 249 SDL_AddThread(thread); | |
| 250 | |
| 251 /* Create the thread and go! */ | |
| 252 ret = SDL_SYS_CreateThread(thread, args); | |
| 253 if ( ret >= 0 ) { | |
| 254 /* Wait for the thread function to use arguments */ | |
| 255 SDL_SemWait(args->wait); | |
| 256 } else { | |
| 257 /* Oops, failed. Gotta free everything */ | |
| 258 SDL_DelThread(thread); | |
| 259 free(thread); | |
| 260 thread = NULL; | |
| 261 } | |
| 262 SDL_DestroySemaphore(args->wait); | |
| 263 free(args); | |
| 264 | |
| 265 /* Everything is running now */ | |
| 266 return(thread); | |
| 267 } | |
| 268 | |
| 269 void SDL_WaitThread(SDL_Thread *thread, int *status) | |
| 270 { | |
| 271 if ( thread ) { | |
| 272 SDL_SYS_WaitThread(thread); | |
| 273 if ( status ) { | |
| 274 *status = thread->status; | |
| 275 } | |
| 276 SDL_DelThread(thread); | |
| 277 free(thread); | |
| 278 } | |
| 279 } | |
| 280 | |
| 281 Uint32 SDL_GetThreadID(SDL_Thread *thread) | |
| 282 { | |
| 283 Uint32 id; | |
| 284 | |
| 285 if ( thread ) { | |
| 286 id = thread->threadid; | |
| 287 } else { | |
| 288 id = SDL_ThreadID(); | |
| 289 } | |
| 290 return(id); | |
| 291 } | |
| 292 | |
| 293 void SDL_KillThread(SDL_Thread *thread) | |
| 294 { | |
| 295 if ( thread ) { | |
| 296 SDL_SYS_KillThread(thread); | |
| 297 SDL_WaitThread(thread, NULL); | |
| 298 } | |
| 299 } | |
| 300 |