Mercurial > sdl-ios-xcode
annotate src/thread/SDL_thread.c @ 378:6089cd59e3ca
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author | Sam Lantinga <slouken@libsdl.org> |
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date | Mon, 20 May 2002 18:36:48 +0000 |
parents | b9f1ce709960 |
children | 283d348cb624 |
rev | line source |
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0 | 1 /* |
2 SDL - Simple DirectMedia Layer | |
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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 | |
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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 | |
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55 #ifdef ENABLE_PTH |
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56 if (!pth_init()) { |
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57 return -1; |
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58 } |
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59 #endif |
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60 |
0 | 61 retval = 0; |
62 /* Set the thread lock creation flag so that we can reuse an | |
63 existing lock on the system - since this mutex never gets | |
64 destroyed (see SDL_ThreadsQuit()), we want to reuse it. | |
65 */ | |
66 _creating_thread_lock = 1; | |
67 thread_lock = SDL_CreateMutex(); | |
68 _creating_thread_lock = 0; | |
69 if ( thread_lock == NULL ) { | |
70 retval = -1; | |
71 } | |
72 return(retval); | |
73 } | |
74 | |
75 /* This should never be called... | |
76 If this is called by SDL_Quit(), we don't know whether or not we should | |
77 clean up threads here. If any threads are still running after this call, | |
78 they will no longer have access to any per-thread data. | |
79 */ | |
80 void SDL_ThreadsQuit() | |
81 { | |
82 SDL_mutex *mutex; | |
83 | |
84 mutex = thread_lock; | |
85 thread_lock = NULL; | |
86 if ( mutex != NULL ) { | |
87 SDL_DestroyMutex(mutex); | |
88 } | |
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89 |
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90 #ifdef ENABLE_PTH |
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91 pth_kill(); |
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92 #endif |
0 | 93 } |
94 | |
95 /* Routines for manipulating the thread list */ | |
96 static void SDL_AddThread(SDL_Thread *thread) | |
97 { | |
98 SDL_Thread **threads; | |
99 | |
100 /* WARNING: | |
101 If the very first threads are created simultaneously, then | |
102 there could be a race condition causing memory corruption. | |
103 In practice, this isn't a problem because by definition there | |
104 is only one thread running the first time this is called. | |
105 */ | |
106 if ( thread_lock == NULL ) { | |
107 if ( SDL_ThreadsInit() < 0 ) { | |
108 return; | |
109 } | |
110 } | |
111 SDL_mutexP(thread_lock); | |
112 | |
113 /* Expand the list of threads, if necessary */ | |
114 #ifdef DEBUG_THREADS | |
115 printf("Adding thread (%d already - %d max)\n", | |
116 SDL_numthreads, SDL_maxthreads); | |
117 #endif | |
118 if ( SDL_numthreads == SDL_maxthreads ) { | |
119 threads=(SDL_Thread **)malloc((SDL_maxthreads+ARRAY_CHUNKSIZE)* | |
120 (sizeof *threads)); | |
121 if ( threads == NULL ) { | |
122 SDL_OutOfMemory(); | |
123 goto done; | |
124 } | |
125 memcpy(threads, SDL_Threads, SDL_numthreads*(sizeof *threads)); | |
126 SDL_maxthreads += ARRAY_CHUNKSIZE; | |
127 if ( SDL_Threads ) { | |
128 free(SDL_Threads); | |
129 } | |
130 SDL_Threads = threads; | |
131 } | |
132 SDL_Threads[SDL_numthreads++] = thread; | |
133 done: | |
134 SDL_mutexV(thread_lock); | |
135 } | |
136 | |
137 static void SDL_DelThread(SDL_Thread *thread) | |
138 { | |
139 int i; | |
140 | |
141 if ( thread_lock ) { | |
142 SDL_mutexP(thread_lock); | |
143 for ( i=0; i<SDL_numthreads; ++i ) { | |
144 if ( thread == SDL_Threads[i] ) { | |
145 break; | |
146 } | |
147 } | |
148 if ( i < SDL_numthreads ) { | |
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149 if ( --SDL_numthreads > 0 ) { |
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150 while ( i < SDL_numthreads ) { |
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151 SDL_Threads[i] = SDL_Threads[i+1]; |
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152 ++i; |
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153 } |
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154 } else { |
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155 SDL_maxthreads = 0; |
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156 free(SDL_Threads); |
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157 SDL_Threads = NULL; |
0 | 158 } |
159 #ifdef DEBUG_THREADS | |
160 printf("Deleting thread (%d left - %d max)\n", | |
161 SDL_numthreads, SDL_maxthreads); | |
162 #endif | |
163 } | |
164 SDL_mutexV(thread_lock); | |
165 } | |
166 } | |
167 | |
168 /* The default (non-thread-safe) global error variable */ | |
169 static SDL_error SDL_global_error; | |
170 | |
171 /* Routine to get the thread-specific error variable */ | |
172 SDL_error *SDL_GetErrBuf(void) | |
173 { | |
174 SDL_error *errbuf; | |
175 | |
176 errbuf = &SDL_global_error; | |
177 if ( SDL_Threads ) { | |
178 int i; | |
179 Uint32 this_thread; | |
180 | |
181 this_thread = SDL_ThreadID(); | |
182 SDL_mutexP(thread_lock); | |
183 for ( i=0; i<SDL_numthreads; ++i ) { | |
184 if ( this_thread == SDL_Threads[i]->threadid ) { | |
185 errbuf = &SDL_Threads[i]->errbuf; | |
186 break; | |
187 } | |
188 } | |
189 SDL_mutexV(thread_lock); | |
190 } | |
191 return(errbuf); | |
192 } | |
193 | |
194 | |
195 /* Arguments and callback to setup and run the user thread function */ | |
196 typedef struct { | |
197 int (*func)(void *); | |
198 void *data; | |
199 SDL_Thread *info; | |
200 SDL_sem *wait; | |
201 } thread_args; | |
202 | |
203 void SDL_RunThread(void *data) | |
204 { | |
205 thread_args *args; | |
206 int (*userfunc)(void *); | |
207 void *userdata; | |
208 int *statusloc; | |
209 | |
210 /* Perform any system-dependent setup | |
211 - this function cannot fail, and cannot use SDL_SetError() | |
212 */ | |
213 SDL_SYS_SetupThread(); | |
214 | |
215 /* Get the thread id */ | |
216 args = (thread_args *)data; | |
217 args->info->threadid = SDL_ThreadID(); | |
218 | |
219 /* Figure out what function to run */ | |
220 userfunc = args->func; | |
221 userdata = args->data; | |
222 statusloc = &args->info->status; | |
223 | |
224 /* Wake up the parent thread */ | |
225 SDL_SemPost(args->wait); | |
226 | |
227 /* Run the function */ | |
228 *statusloc = userfunc(userdata); | |
229 } | |
230 | |
231 SDL_Thread *SDL_CreateThread(int (*fn)(void *), void *data) | |
232 { | |
233 SDL_Thread *thread; | |
234 thread_args *args; | |
235 int ret; | |
236 | |
237 /* Allocate memory for the thread info structure */ | |
238 thread = (SDL_Thread *)malloc(sizeof(*thread)); | |
239 if ( thread == NULL ) { | |
240 SDL_OutOfMemory(); | |
241 return(NULL); | |
242 } | |
243 memset(thread, 0, (sizeof *thread)); | |
244 thread->status = -1; | |
245 | |
246 /* Set up the arguments for the thread */ | |
247 args = (thread_args *)malloc(sizeof(*args)); | |
248 if ( args == NULL ) { | |
249 SDL_OutOfMemory(); | |
250 free(thread); | |
251 return(NULL); | |
252 } | |
253 args->func = fn; | |
254 args->data = data; | |
255 args->info = thread; | |
256 args->wait = SDL_CreateSemaphore(0); | |
257 if ( args->wait == NULL ) { | |
258 free(thread); | |
259 free(args); | |
260 return(NULL); | |
261 } | |
262 | |
263 /* Add the thread to the list of available threads */ | |
264 SDL_AddThread(thread); | |
265 | |
266 /* Create the thread and go! */ | |
267 ret = SDL_SYS_CreateThread(thread, args); | |
268 if ( ret >= 0 ) { | |
269 /* Wait for the thread function to use arguments */ | |
270 SDL_SemWait(args->wait); | |
271 } else { | |
272 /* Oops, failed. Gotta free everything */ | |
273 SDL_DelThread(thread); | |
274 free(thread); | |
275 thread = NULL; | |
276 } | |
277 SDL_DestroySemaphore(args->wait); | |
278 free(args); | |
279 | |
280 /* Everything is running now */ | |
281 return(thread); | |
282 } | |
283 | |
284 void SDL_WaitThread(SDL_Thread *thread, int *status) | |
285 { | |
286 if ( thread ) { | |
287 SDL_SYS_WaitThread(thread); | |
288 if ( status ) { | |
289 *status = thread->status; | |
290 } | |
291 SDL_DelThread(thread); | |
292 free(thread); | |
293 } | |
294 } | |
295 | |
296 Uint32 SDL_GetThreadID(SDL_Thread *thread) | |
297 { | |
298 Uint32 id; | |
299 | |
300 if ( thread ) { | |
301 id = thread->threadid; | |
302 } else { | |
303 id = SDL_ThreadID(); | |
304 } | |
305 return(id); | |
306 } | |
307 | |
308 void SDL_KillThread(SDL_Thread *thread) | |
309 { | |
310 if ( thread ) { | |
311 SDL_SYS_KillThread(thread); | |
312 SDL_WaitThread(thread, NULL); | |
313 } | |
314 } | |
315 |