Mercurial > sdl-ios-xcode
annotate src/thread/SDL_thread.c @ 4355:9b464226e541 SDL-1.2
Fixed bug #855
Ludwig Nussel 2009-10-18 06:31:52 PDT
an mprotect call was added to fix bug 528. However that results in a buffer
that allows writing and code execution. Ie the no-execute security features of
modern operating systems are defeated this way. Two mprotect calls are needed.
One to make the buffer executable but not writeable when done and another one
to make the buffer writeable again if the content needs to be changed.
| author | Sam Lantinga <slouken@libsdl.org> |
|---|---|
| date | Sun, 18 Oct 2009 17:31:37 +0000 |
| parents | 88aa213ffc7b |
| children |
| rev | line source |
|---|---|
| 0 | 1 /* |
| 2 SDL - Simple DirectMedia Layer | |
| 4159 | 3 Copyright (C) 1997-2009 Sam Lantinga |
| 0 | 4 |
| 5 This library is free software; you can redistribute it and/or | |
|
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Updated copyright information and removed rcs id lines (problematic in branch merges)
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6 modify it under the terms of the GNU Lesser General Public |
| 0 | 7 License as published by the Free Software Foundation; either |
|
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Updated copyright information and removed rcs id lines (problematic in branch merges)
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8 version 2.1 of the License, or (at your option) any later version. |
| 0 | 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 | |
|
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Updated copyright information and removed rcs id lines (problematic in branch merges)
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parents:
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13 Lesser General Public License for more details. |
| 0 | 14 |
|
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Updated copyright information and removed rcs id lines (problematic in branch merges)
Sam Lantinga <slouken@libsdl.org>
parents:
1190
diff
changeset
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15 You should have received a copy of the GNU Lesser General Public |
|
c9b51268668f
Updated copyright information and removed rcs id lines (problematic in branch merges)
Sam Lantinga <slouken@libsdl.org>
parents:
1190
diff
changeset
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16 License along with this library; if not, write to the Free Software |
|
c9b51268668f
Updated copyright information and removed rcs id lines (problematic in branch merges)
Sam Lantinga <slouken@libsdl.org>
parents:
1190
diff
changeset
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17 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA |
| 0 | 18 |
| 19 Sam Lantinga | |
|
252
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Updated the source with the correct e-mail address
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20 slouken@libsdl.org |
| 0 | 21 */ |
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Use consistent identifiers for the various platforms we support.
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22 #include "SDL_config.h" |
| 0 | 23 |
| 24 /* System independent thread management routines for SDL */ | |
| 25 | |
| 26 #include "SDL_mutex.h" | |
| 27 #include "SDL_thread.h" | |
| 28 #include "SDL_thread_c.h" | |
| 29 #include "SDL_systhread.h" | |
| 30 | |
| 31 #define ARRAY_CHUNKSIZE 32 | |
| 32 /* The array of threads currently active in the application | |
| 33 (except the main thread) | |
| 34 The manipulation of an array here is safer than using a linked list. | |
| 35 */ | |
| 36 static int SDL_maxthreads = 0; | |
| 37 static int SDL_numthreads = 0; | |
| 38 static SDL_Thread **SDL_Threads = NULL; | |
| 39 static SDL_mutex *thread_lock = NULL; | |
| 40 | |
| 41 int SDL_ThreadsInit(void) | |
| 42 { | |
| 43 int retval; | |
| 44 | |
| 45 retval = 0; | |
| 46 thread_lock = SDL_CreateMutex(); | |
| 47 if ( thread_lock == NULL ) { | |
| 48 retval = -1; | |
| 49 } | |
| 50 return(retval); | |
| 51 } | |
| 52 | |
| 53 /* This should never be called... | |
| 54 If this is called by SDL_Quit(), we don't know whether or not we should | |
| 55 clean up threads here. If any threads are still running after this call, | |
| 56 they will no longer have access to any per-thread data. | |
| 57 */ | |
|
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Fixed some ultra-pedantic gcc warnings
Sam Lantinga <slouken@libsdl.org>
parents:
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58 void SDL_ThreadsQuit(void) |
| 0 | 59 { |
| 60 SDL_mutex *mutex; | |
| 61 | |
| 62 mutex = thread_lock; | |
| 63 thread_lock = NULL; | |
| 64 if ( mutex != NULL ) { | |
| 65 SDL_DestroyMutex(mutex); | |
| 66 } | |
| 67 } | |
| 68 | |
| 69 /* Routines for manipulating the thread list */ | |
| 70 static void SDL_AddThread(SDL_Thread *thread) | |
| 71 { | |
| 72 /* WARNING: | |
| 73 If the very first threads are created simultaneously, then | |
| 74 there could be a race condition causing memory corruption. | |
| 75 In practice, this isn't a problem because by definition there | |
| 76 is only one thread running the first time this is called. | |
| 77 */ | |
| 1499 | 78 if ( !thread_lock ) { |
| 0 | 79 if ( SDL_ThreadsInit() < 0 ) { |
| 80 return; | |
| 81 } | |
| 82 } | |
| 83 SDL_mutexP(thread_lock); | |
| 84 | |
| 85 /* Expand the list of threads, if necessary */ | |
| 86 #ifdef DEBUG_THREADS | |
| 87 printf("Adding thread (%d already - %d max)\n", | |
| 88 SDL_numthreads, SDL_maxthreads); | |
| 89 #endif | |
| 90 if ( SDL_numthreads == SDL_maxthreads ) { | |
| 1499 | 91 SDL_Thread **threads; |
| 92 threads = (SDL_Thread **)SDL_realloc(SDL_Threads, | |
| 93 (SDL_maxthreads+ARRAY_CHUNKSIZE)*(sizeof *threads)); | |
| 0 | 94 if ( threads == NULL ) { |
| 95 SDL_OutOfMemory(); | |
| 96 goto done; | |
| 97 } | |
| 98 SDL_maxthreads += ARRAY_CHUNKSIZE; | |
| 99 SDL_Threads = threads; | |
| 100 } | |
| 101 SDL_Threads[SDL_numthreads++] = thread; | |
| 102 done: | |
| 103 SDL_mutexV(thread_lock); | |
| 104 } | |
| 105 | |
| 106 static void SDL_DelThread(SDL_Thread *thread) | |
| 107 { | |
| 108 int i; | |
| 109 | |
| 1499 | 110 if ( !thread_lock ) { |
| 111 return; | |
| 112 } | |
| 113 SDL_mutexP(thread_lock); | |
| 114 for ( i=0; i<SDL_numthreads; ++i ) { | |
| 115 if ( thread == SDL_Threads[i] ) { | |
| 116 break; | |
| 0 | 117 } |
| 1499 | 118 } |
| 119 if ( i < SDL_numthreads ) { | |
| 120 if ( --SDL_numthreads > 0 ) { | |
| 121 while ( i < SDL_numthreads ) { | |
| 122 SDL_Threads[i] = SDL_Threads[i+1]; | |
| 123 ++i; | |
| 0 | 124 } |
| 1499 | 125 } else { |
| 126 SDL_maxthreads = 0; | |
| 127 SDL_free(SDL_Threads); | |
| 128 SDL_Threads = NULL; | |
| 129 } | |
| 0 | 130 #ifdef DEBUG_THREADS |
| 1499 | 131 printf("Deleting thread (%d left - %d max)\n", |
| 132 SDL_numthreads, SDL_maxthreads); | |
| 0 | 133 #endif |
| 1499 | 134 } |
| 135 SDL_mutexV(thread_lock); | |
| 136 | |
|
4235
88aa213ffc7b
Possibly fixed bug #601, definitely fixed a potential issue with threads
Sam Lantinga <slouken@libsdl.org>
parents:
4159
diff
changeset
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137 #if 0 /* There could be memory corruption if another thread is starting */ |
| 1499 | 138 if ( SDL_Threads == NULL ) { |
| 139 SDL_ThreadsQuit(); | |
| 0 | 140 } |
|
4235
88aa213ffc7b
Possibly fixed bug #601, definitely fixed a potential issue with threads
Sam Lantinga <slouken@libsdl.org>
parents:
4159
diff
changeset
|
141 #endif |
| 0 | 142 } |
| 143 | |
| 144 /* The default (non-thread-safe) global error variable */ | |
| 145 static SDL_error SDL_global_error; | |
| 146 | |
| 147 /* Routine to get the thread-specific error variable */ | |
| 148 SDL_error *SDL_GetErrBuf(void) | |
| 149 { | |
| 150 SDL_error *errbuf; | |
| 151 | |
| 152 errbuf = &SDL_global_error; | |
| 153 if ( SDL_Threads ) { | |
| 154 int i; | |
| 155 Uint32 this_thread; | |
| 156 | |
| 157 this_thread = SDL_ThreadID(); | |
| 158 SDL_mutexP(thread_lock); | |
| 159 for ( i=0; i<SDL_numthreads; ++i ) { | |
| 160 if ( this_thread == SDL_Threads[i]->threadid ) { | |
| 161 errbuf = &SDL_Threads[i]->errbuf; | |
| 162 break; | |
| 163 } | |
| 164 } | |
| 165 SDL_mutexV(thread_lock); | |
| 166 } | |
| 167 return(errbuf); | |
| 168 } | |
| 169 | |
| 170 | |
| 171 /* Arguments and callback to setup and run the user thread function */ | |
| 172 typedef struct { | |
| 1769 | 173 int (SDLCALL *func)(void *); |
| 0 | 174 void *data; |
| 175 SDL_Thread *info; | |
| 176 SDL_sem *wait; | |
| 177 } thread_args; | |
| 178 | |
| 179 void SDL_RunThread(void *data) | |
| 180 { | |
| 181 thread_args *args; | |
| 1769 | 182 int (SDLCALL *userfunc)(void *); |
| 0 | 183 void *userdata; |
| 184 int *statusloc; | |
| 185 | |
| 186 /* Perform any system-dependent setup | |
| 187 - this function cannot fail, and cannot use SDL_SetError() | |
| 188 */ | |
| 189 SDL_SYS_SetupThread(); | |
| 190 | |
| 191 /* Get the thread id */ | |
| 192 args = (thread_args *)data; | |
| 193 args->info->threadid = SDL_ThreadID(); | |
| 194 | |
| 195 /* Figure out what function to run */ | |
| 196 userfunc = args->func; | |
| 197 userdata = args->data; | |
| 198 statusloc = &args->info->status; | |
| 199 | |
| 200 /* Wake up the parent thread */ | |
| 201 SDL_SemPost(args->wait); | |
| 202 | |
| 203 /* Run the function */ | |
| 204 *statusloc = userfunc(userdata); | |
| 205 } | |
| 206 | |
|
1471
9fb0eee04dd9
Enabled libc support on Win32, so we don't break binary compatibility in 1.2
Sam Lantinga <slouken@libsdl.org>
parents:
1402
diff
changeset
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207 #ifdef SDL_PASSED_BEGINTHREAD_ENDTHREAD |
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1330
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It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
1312
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208 #undef SDL_CreateThread |
| 1769 | 209 DECLSPEC SDL_Thread * SDLCALL SDL_CreateThread(int (SDLCALL *fn)(void *), void *data, pfnSDL_CurrentBeginThread pfnBeginThread, pfnSDL_CurrentEndThread pfnEndThread) |
| 1190 | 210 #else |
| 1769 | 211 DECLSPEC SDL_Thread * SDLCALL SDL_CreateThread(int (SDLCALL *fn)(void *), void *data) |
| 1190 | 212 #endif |
| 0 | 213 { |
| 214 SDL_Thread *thread; | |
| 215 thread_args *args; | |
| 216 int ret; | |
| 217 | |
| 218 /* Allocate memory for the thread info structure */ | |
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parents:
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219 thread = (SDL_Thread *)SDL_malloc(sizeof(*thread)); |
| 0 | 220 if ( thread == NULL ) { |
| 221 SDL_OutOfMemory(); | |
| 222 return(NULL); | |
| 223 } | |
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parents:
1330
diff
changeset
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224 SDL_memset(thread, 0, (sizeof *thread)); |
| 0 | 225 thread->status = -1; |
| 226 | |
| 227 /* Set up the arguments for the thread */ | |
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1336
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Use SDL_ prefixed versions of C library functions.
Sam Lantinga <slouken@libsdl.org>
parents:
1330
diff
changeset
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228 args = (thread_args *)SDL_malloc(sizeof(*args)); |
| 0 | 229 if ( args == NULL ) { |
| 230 SDL_OutOfMemory(); | |
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1336
3692456e7b0f
Use SDL_ prefixed versions of C library functions.
Sam Lantinga <slouken@libsdl.org>
parents:
1330
diff
changeset
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231 SDL_free(thread); |
| 0 | 232 return(NULL); |
| 233 } | |
| 234 args->func = fn; | |
| 235 args->data = data; | |
| 236 args->info = thread; | |
| 237 args->wait = SDL_CreateSemaphore(0); | |
| 238 if ( args->wait == NULL ) { | |
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3692456e7b0f
Use SDL_ prefixed versions of C library functions.
Sam Lantinga <slouken@libsdl.org>
parents:
1330
diff
changeset
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239 SDL_free(thread); |
|
3692456e7b0f
Use SDL_ prefixed versions of C library functions.
Sam Lantinga <slouken@libsdl.org>
parents:
1330
diff
changeset
|
240 SDL_free(args); |
| 0 | 241 return(NULL); |
| 242 } | |
| 243 | |
| 244 /* Add the thread to the list of available threads */ | |
| 245 SDL_AddThread(thread); | |
| 246 | |
| 247 /* Create the thread and go! */ | |
|
1471
9fb0eee04dd9
Enabled libc support on Win32, so we don't break binary compatibility in 1.2
Sam Lantinga <slouken@libsdl.org>
parents:
1402
diff
changeset
|
248 #ifdef SDL_PASSED_BEGINTHREAD_ENDTHREAD |
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1330
450721ad5436
It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
1312
diff
changeset
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249 ret = SDL_SYS_CreateThread(thread, args, pfnBeginThread, pfnEndThread); |
| 1190 | 250 #else |
| 0 | 251 ret = SDL_SYS_CreateThread(thread, args); |
| 1190 | 252 #endif |
| 0 | 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); | |
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Sam Lantinga <slouken@libsdl.org>
parents:
1330
diff
changeset
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259 SDL_free(thread); |
| 0 | 260 thread = NULL; |
| 261 } | |
| 262 SDL_DestroySemaphore(args->wait); | |
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Sam Lantinga <slouken@libsdl.org>
parents:
1330
diff
changeset
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263 SDL_free(args); |
| 0 | 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); | |
|
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Use SDL_ prefixed versions of C library functions.
Sam Lantinga <slouken@libsdl.org>
parents:
1330
diff
changeset
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277 SDL_free(thread); |
| 0 | 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 |