Mercurial > sdl-ios-xcode
annotate src/thread/SDL_thread.c @ 329:1d74ddc90cb2
Patrice's fixes for GNU Pthread support
author | Sam Lantinga <slouken@libsdl.org> |
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date | Mon, 01 Apr 2002 15:35:28 +0000 |
parents | f6ffac90895c |
children | b9f1ce709960 |
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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parents:
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59 #endif |
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parents:
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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 ) { | |
149 --SDL_numthreads; | |
150 while ( i < SDL_numthreads ) { | |
151 SDL_Threads[i] = SDL_Threads[i+1]; | |
152 ++i; | |
153 } | |
154 #ifdef DEBUG_THREADS | |
155 printf("Deleting thread (%d left - %d max)\n", | |
156 SDL_numthreads, SDL_maxthreads); | |
157 #endif | |
158 } | |
159 SDL_mutexV(thread_lock); | |
160 } | |
161 } | |
162 | |
163 /* The default (non-thread-safe) global error variable */ | |
164 static SDL_error SDL_global_error; | |
165 | |
166 /* Routine to get the thread-specific error variable */ | |
167 SDL_error *SDL_GetErrBuf(void) | |
168 { | |
169 SDL_error *errbuf; | |
170 | |
171 errbuf = &SDL_global_error; | |
172 if ( SDL_Threads ) { | |
173 int i; | |
174 Uint32 this_thread; | |
175 | |
176 this_thread = SDL_ThreadID(); | |
177 SDL_mutexP(thread_lock); | |
178 for ( i=0; i<SDL_numthreads; ++i ) { | |
179 if ( this_thread == SDL_Threads[i]->threadid ) { | |
180 errbuf = &SDL_Threads[i]->errbuf; | |
181 break; | |
182 } | |
183 } | |
184 SDL_mutexV(thread_lock); | |
185 } | |
186 return(errbuf); | |
187 } | |
188 | |
189 | |
190 /* Arguments and callback to setup and run the user thread function */ | |
191 typedef struct { | |
192 int (*func)(void *); | |
193 void *data; | |
194 SDL_Thread *info; | |
195 SDL_sem *wait; | |
196 } thread_args; | |
197 | |
198 void SDL_RunThread(void *data) | |
199 { | |
200 thread_args *args; | |
201 int (*userfunc)(void *); | |
202 void *userdata; | |
203 int *statusloc; | |
204 | |
205 /* Perform any system-dependent setup | |
206 - this function cannot fail, and cannot use SDL_SetError() | |
207 */ | |
208 SDL_SYS_SetupThread(); | |
209 | |
210 /* Get the thread id */ | |
211 args = (thread_args *)data; | |
212 args->info->threadid = SDL_ThreadID(); | |
213 | |
214 /* Figure out what function to run */ | |
215 userfunc = args->func; | |
216 userdata = args->data; | |
217 statusloc = &args->info->status; | |
218 | |
219 /* Wake up the parent thread */ | |
220 SDL_SemPost(args->wait); | |
221 | |
222 /* Run the function */ | |
223 *statusloc = userfunc(userdata); | |
224 } | |
225 | |
226 SDL_Thread *SDL_CreateThread(int (*fn)(void *), void *data) | |
227 { | |
228 SDL_Thread *thread; | |
229 thread_args *args; | |
230 int ret; | |
231 | |
232 /* Allocate memory for the thread info structure */ | |
233 thread = (SDL_Thread *)malloc(sizeof(*thread)); | |
234 if ( thread == NULL ) { | |
235 SDL_OutOfMemory(); | |
236 return(NULL); | |
237 } | |
238 memset(thread, 0, (sizeof *thread)); | |
239 thread->status = -1; | |
240 | |
241 /* Set up the arguments for the thread */ | |
242 args = (thread_args *)malloc(sizeof(*args)); | |
243 if ( args == NULL ) { | |
244 SDL_OutOfMemory(); | |
245 free(thread); | |
246 return(NULL); | |
247 } | |
248 args->func = fn; | |
249 args->data = data; | |
250 args->info = thread; | |
251 args->wait = SDL_CreateSemaphore(0); | |
252 if ( args->wait == NULL ) { | |
253 free(thread); | |
254 free(args); | |
255 return(NULL); | |
256 } | |
257 | |
258 /* Add the thread to the list of available threads */ | |
259 SDL_AddThread(thread); | |
260 | |
261 /* Create the thread and go! */ | |
262 ret = SDL_SYS_CreateThread(thread, args); | |
263 if ( ret >= 0 ) { | |
264 /* Wait for the thread function to use arguments */ | |
265 SDL_SemWait(args->wait); | |
266 } else { | |
267 /* Oops, failed. Gotta free everything */ | |
268 SDL_DelThread(thread); | |
269 free(thread); | |
270 thread = NULL; | |
271 } | |
272 SDL_DestroySemaphore(args->wait); | |
273 free(args); | |
274 | |
275 /* Everything is running now */ | |
276 return(thread); | |
277 } | |
278 | |
279 void SDL_WaitThread(SDL_Thread *thread, int *status) | |
280 { | |
281 if ( thread ) { | |
282 SDL_SYS_WaitThread(thread); | |
283 if ( status ) { | |
284 *status = thread->status; | |
285 } | |
286 SDL_DelThread(thread); | |
287 free(thread); | |
288 } | |
289 } | |
290 | |
291 Uint32 SDL_GetThreadID(SDL_Thread *thread) | |
292 { | |
293 Uint32 id; | |
294 | |
295 if ( thread ) { | |
296 id = thread->threadid; | |
297 } else { | |
298 id = SDL_ThreadID(); | |
299 } | |
300 return(id); | |
301 } | |
302 | |
303 void SDL_KillThread(SDL_Thread *thread) | |
304 { | |
305 if ( thread ) { | |
306 SDL_SYS_KillThread(thread); | |
307 SDL_WaitThread(thread, NULL); | |
308 } | |
309 } | |
310 |