Mercurial > sdl-ios-xcode
annotate src/thread/SDL_thread.c @ 297:f6ffac90895c
Updated copyright information for 2002
author | Sam Lantinga <slouken@libsdl.org> |
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date | Wed, 06 Mar 2002 11:23:08 +0000 |
parents | e8157fcb3114 |
children | 1d74ddc90cb2 |
rev | line source |
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0 | 1 /* |
2 SDL - Simple DirectMedia Layer | |
297
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Updated copyright information for 2002
Sam Lantinga <slouken@libsdl.org>
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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 | |
252
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Updated the source with the correct e-mail address
Sam Lantinga <slouken@libsdl.org>
parents:
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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 |