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6319d58e | 1 | /* Threads compatibility routines for libgcc2 and libobjc. */ |
471528fc | 2 | /* Compile this one with gcc. */ |
04641143 | 3 | /* Copyright (C) 1999, 2000, 2002 Free Software Foundation, Inc. |
471528fc | 4 | Contributed by Mumit Khan <khan@xraylith.wisc.edu>. |
5 | ||
f12b58b3 | 6 | This file is part of GCC. |
471528fc | 7 | |
f12b58b3 | 8 | GCC is free software; you can redistribute it and/or modify it under |
9 | the terms of the GNU General Public License as published by the Free | |
10 | Software Foundation; either version 2, or (at your option) any later | |
11 | version. | |
471528fc | 12 | |
f12b58b3 | 13 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY |
14 | WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
15 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
16 | for more details. | |
471528fc | 17 | |
18 | You should have received a copy of the GNU General Public License | |
f12b58b3 | 19 | along with GCC; see the file COPYING. If not, write to the Free |
20 | Software Foundation, 59 Temple Place - Suite 330, Boston, MA | |
21 | 02111-1307, USA. */ | |
471528fc | 22 | |
23 | /* As a special exception, if you link this library with other files, | |
24 | some of which are compiled with GCC, to produce an executable, | |
25 | this library does not by itself cause the resulting executable | |
26 | to be covered by the GNU General Public License. | |
27 | This exception does not however invalidate any other reasons why | |
28 | the executable file might be covered by the GNU General Public License. */ | |
29 | ||
2a281353 | 30 | #ifndef GCC_GTHR_WIN32_H |
31 | #define GCC_GTHR_WIN32_H | |
471528fc | 32 | |
33 | /* Windows32 threads specific definitions. The windows32 threading model | |
3cfec666 | 34 | does not map well into pthread-inspired gcc's threading model, and so |
471528fc | 35 | there are caveats one needs to be aware of. |
36 | ||
c13f265c | 37 | 1. The destructor supplied to __gthread_key_create is ignored for |
3cfec666 | 38 | generic x86-win32 ports. This will certainly cause memory leaks |
39 | due to unreclaimed eh contexts (sizeof (eh_context) is at least | |
c13f265c | 40 | 24 bytes for x86 currently). |
471528fc | 41 | |
42 | This memory leak may be significant for long-running applications | |
43 | that make heavy use of C++ EH. | |
44 | ||
c13f265c | 45 | However, Mingw runtime (version 0.3 or newer) provides a mechanism |
46 | to emulate pthreads key dtors; the runtime provides a special DLL, | |
47 | linked in if -mthreads option is specified, that runs the dtors in | |
48 | the reverse order of registration when each thread exits. If | |
49 | -mthreads option is not given, a stub is linked in instead of the | |
3cfec666 | 50 | DLL, which results in memory leak. Other x86-win32 ports can use |
c13f265c | 51 | the same technique of course to avoid the leak. |
52 | ||
471528fc | 53 | 2. The error codes returned are non-POSIX like, and cast into ints. |
3cfec666 | 54 | This may cause incorrect error return due to truncation values on |
471528fc | 55 | hw where sizeof (DWORD) > sizeof (int). |
3cfec666 | 56 | |
57 | 3. We might consider using Critical Sections instead of Windows32 | |
58 | mutexes for better performance, but emulating __gthread_mutex_trylock | |
c13f265c | 59 | interface becomes more complicated (Win9x does not support |
60 | TryEnterCriticalSectioni, while NT does). | |
3cfec666 | 61 | |
c13f265c | 62 | The basic framework should work well enough. In the long term, GCC |
63 | needs to use Structured Exception Handling on Windows32. */ | |
471528fc | 64 | |
65 | #define __GTHREADS 1 | |
66 | ||
81189303 | 67 | #include <errno.h> |
68 | #ifdef __MINGW32__ | |
69 | #include <_mingw.h> | |
70 | #endif | |
6319d58e | 71 | |
72 | #ifdef _LIBOBJC | |
73 | ||
61dcce9c | 74 | /* This is necessary to prevent windef.h (included from windows.h) from |
3cfec666 | 75 | defining it's own BOOL as a typedef. */ |
61dcce9c | 76 | #ifndef __OBJC__ |
77 | #define __OBJC__ | |
78 | #endif | |
79 | #include <windows.h> | |
3cfec666 | 80 | /* Now undef the windows BOOL. */ |
61dcce9c | 81 | #undef BOOL |
82 | ||
6319d58e | 83 | /* Key structure for maintaining thread specific storage */ |
84 | static DWORD __gthread_objc_data_tls = (DWORD)-1; | |
85 | ||
86 | /* Backend initialization functions */ | |
87 | ||
5a54c45e | 88 | /* Initialize the threads subsystem. */ |
6319d58e | 89 | int |
90 | __gthread_objc_init_thread_system(void) | |
91 | { | |
92 | /* Initialize the thread storage key */ | |
93 | if ((__gthread_objc_data_tls = TlsAlloc()) != (DWORD)-1) | |
94 | return 0; | |
95 | else | |
96 | return -1; | |
97 | } | |
98 | ||
5a54c45e | 99 | /* Close the threads subsystem. */ |
6319d58e | 100 | int |
101 | __gthread_objc_close_thread_system(void) | |
102 | { | |
103 | if (__gthread_objc_data_tls != (DWORD)-1) | |
104 | TlsFree(__gthread_objc_data_tls); | |
105 | return 0; | |
106 | } | |
107 | ||
108 | /* Backend thread functions */ | |
109 | ||
5a54c45e | 110 | /* Create a new thread of execution. */ |
6319d58e | 111 | objc_thread_t |
112 | __gthread_objc_thread_detach(void (*func)(void *arg), void *arg) | |
113 | { | |
114 | DWORD thread_id = 0; | |
115 | HANDLE win32_handle; | |
116 | ||
117 | if (!(win32_handle = CreateThread(NULL, 0, (LPTHREAD_START_ROUTINE)func, | |
3cfec666 | 118 | arg, 0, &thread_id))) |
6319d58e | 119 | thread_id = 0; |
3cfec666 | 120 | |
6319d58e | 121 | return (objc_thread_t)thread_id; |
122 | } | |
123 | ||
5a54c45e | 124 | /* Set the current thread's priority. */ |
6319d58e | 125 | int |
126 | __gthread_objc_thread_set_priority(int priority) | |
127 | { | |
128 | int sys_priority = 0; | |
129 | ||
130 | switch (priority) | |
131 | { | |
132 | case OBJC_THREAD_INTERACTIVE_PRIORITY: | |
133 | sys_priority = THREAD_PRIORITY_NORMAL; | |
134 | break; | |
135 | default: | |
136 | case OBJC_THREAD_BACKGROUND_PRIORITY: | |
137 | sys_priority = THREAD_PRIORITY_BELOW_NORMAL; | |
138 | break; | |
139 | case OBJC_THREAD_LOW_PRIORITY: | |
140 | sys_priority = THREAD_PRIORITY_LOWEST; | |
141 | break; | |
142 | } | |
143 | ||
144 | /* Change priority */ | |
145 | if (SetThreadPriority(GetCurrentThread(), sys_priority)) | |
146 | return 0; | |
147 | else | |
148 | return -1; | |
149 | } | |
150 | ||
5a54c45e | 151 | /* Return the current thread's priority. */ |
6319d58e | 152 | int |
153 | __gthread_objc_thread_get_priority(void) | |
154 | { | |
155 | int sys_priority; | |
156 | ||
157 | sys_priority = GetThreadPriority(GetCurrentThread()); | |
3cfec666 | 158 | |
6319d58e | 159 | switch (sys_priority) |
160 | { | |
161 | case THREAD_PRIORITY_HIGHEST: | |
162 | case THREAD_PRIORITY_TIME_CRITICAL: | |
163 | case THREAD_PRIORITY_ABOVE_NORMAL: | |
164 | case THREAD_PRIORITY_NORMAL: | |
165 | return OBJC_THREAD_INTERACTIVE_PRIORITY; | |
166 | ||
167 | default: | |
168 | case THREAD_PRIORITY_BELOW_NORMAL: | |
169 | return OBJC_THREAD_BACKGROUND_PRIORITY; | |
3cfec666 | 170 | |
6319d58e | 171 | case THREAD_PRIORITY_IDLE: |
172 | case THREAD_PRIORITY_LOWEST: | |
173 | return OBJC_THREAD_LOW_PRIORITY; | |
174 | } | |
175 | ||
5a54c45e | 176 | /* Couldn't get priority. */ |
6319d58e | 177 | return -1; |
178 | } | |
179 | ||
5a54c45e | 180 | /* Yield our process time to another thread. */ |
6319d58e | 181 | void |
182 | __gthread_objc_thread_yield(void) | |
183 | { | |
184 | Sleep(0); | |
185 | } | |
186 | ||
5a54c45e | 187 | /* Terminate the current thread. */ |
6319d58e | 188 | int |
189 | __gthread_objc_thread_exit(void) | |
190 | { | |
191 | /* exit the thread */ | |
e066425d | 192 | ExitThread(__objc_thread_exit_status); |
6319d58e | 193 | |
194 | /* Failed if we reached here */ | |
195 | return -1; | |
196 | } | |
197 | ||
5a54c45e | 198 | /* Returns an integer value which uniquely describes a thread. */ |
6319d58e | 199 | objc_thread_t |
200 | __gthread_objc_thread_id(void) | |
201 | { | |
202 | return (objc_thread_t)GetCurrentThreadId(); | |
203 | } | |
204 | ||
5a54c45e | 205 | /* Sets the thread's local storage pointer. */ |
6319d58e | 206 | int |
207 | __gthread_objc_thread_set_data(void *value) | |
208 | { | |
209 | if (TlsSetValue(__gthread_objc_data_tls, value)) | |
210 | return 0; | |
211 | else | |
212 | return -1; | |
213 | } | |
214 | ||
5a54c45e | 215 | /* Returns the thread's local storage pointer. */ |
6319d58e | 216 | void * |
217 | __gthread_objc_thread_get_data(void) | |
218 | { | |
bc7da7ad | 219 | DWORD lasterror; |
220 | void *ptr; | |
221 | ||
222 | lasterror = GetLastError(); | |
223 | ||
04641143 | 224 | ptr = TlsGetValue(__gthread_objc_data_tls); /* Return thread data. */ |
bc7da7ad | 225 | |
226 | SetLastError( lasterror ); | |
227 | ||
228 | return ptr; | |
6319d58e | 229 | } |
230 | ||
231 | /* Backend mutex functions */ | |
232 | ||
5a54c45e | 233 | /* Allocate a mutex. */ |
6319d58e | 234 | int |
235 | __gthread_objc_mutex_allocate(objc_mutex_t mutex) | |
236 | { | |
237 | if ((mutex->backend = (void *)CreateMutex(NULL, 0, NULL)) == NULL) | |
238 | return -1; | |
239 | else | |
240 | return 0; | |
241 | } | |
242 | ||
5a54c45e | 243 | /* Deallocate a mutex. */ |
6319d58e | 244 | int |
245 | __gthread_objc_mutex_deallocate(objc_mutex_t mutex) | |
246 | { | |
247 | CloseHandle((HANDLE)(mutex->backend)); | |
248 | return 0; | |
249 | } | |
250 | ||
5a54c45e | 251 | /* Grab a lock on a mutex. */ |
6319d58e | 252 | int |
253 | __gthread_objc_mutex_lock(objc_mutex_t mutex) | |
254 | { | |
255 | int status; | |
256 | ||
257 | status = WaitForSingleObject((HANDLE)(mutex->backend), INFINITE); | |
258 | if (status != WAIT_OBJECT_0 && status != WAIT_ABANDONED) | |
259 | return -1; | |
260 | else | |
261 | return 0; | |
262 | } | |
263 | ||
5a54c45e | 264 | /* Try to grab a lock on a mutex. */ |
6319d58e | 265 | int |
266 | __gthread_objc_mutex_trylock(objc_mutex_t mutex) | |
267 | { | |
268 | int status; | |
269 | ||
270 | status = WaitForSingleObject((HANDLE)(mutex->backend), 0); | |
271 | if (status != WAIT_OBJECT_0 && status != WAIT_ABANDONED) | |
272 | return -1; | |
273 | else | |
274 | return 0; | |
275 | } | |
276 | ||
277 | /* Unlock the mutex */ | |
278 | int | |
279 | __gthread_objc_mutex_unlock(objc_mutex_t mutex) | |
280 | { | |
281 | if (ReleaseMutex((HANDLE)(mutex->backend)) == 0) | |
282 | return -1; | |
283 | else | |
284 | return 0; | |
285 | } | |
286 | ||
287 | /* Backend condition mutex functions */ | |
288 | ||
5a54c45e | 289 | /* Allocate a condition. */ |
6319d58e | 290 | int |
291 | __gthread_objc_condition_allocate(objc_condition_t condition) | |
292 | { | |
5a54c45e | 293 | /* Unimplemented. */ |
6319d58e | 294 | return -1; |
295 | } | |
296 | ||
5a54c45e | 297 | /* Deallocate a condition. */ |
6319d58e | 298 | int |
299 | __gthread_objc_condition_deallocate(objc_condition_t condition) | |
300 | { | |
5a54c45e | 301 | /* Unimplemented. */ |
6319d58e | 302 | return -1; |
303 | } | |
304 | ||
305 | /* Wait on the condition */ | |
306 | int | |
307 | __gthread_objc_condition_wait(objc_condition_t condition, objc_mutex_t mutex) | |
308 | { | |
5a54c45e | 309 | /* Unimplemented. */ |
6319d58e | 310 | return -1; |
311 | } | |
312 | ||
5a54c45e | 313 | /* Wake up all threads waiting on this condition. */ |
6319d58e | 314 | int |
315 | __gthread_objc_condition_broadcast(objc_condition_t condition) | |
316 | { | |
5a54c45e | 317 | /* Unimplemented. */ |
6319d58e | 318 | return -1; |
319 | } | |
320 | ||
5a54c45e | 321 | /* Wake up one thread waiting on this condition. */ |
6319d58e | 322 | int |
323 | __gthread_objc_condition_signal(objc_condition_t condition) | |
324 | { | |
5a54c45e | 325 | /* Unimplemented. */ |
6319d58e | 326 | return -1; |
327 | } | |
328 | ||
329 | #else /* _LIBOBJC */ | |
330 | ||
61dcce9c | 331 | #include <windows.h> |
471528fc | 332 | |
333 | typedef DWORD __gthread_key_t; | |
334 | ||
335 | typedef struct { | |
336 | int done; | |
337 | long started; | |
338 | } __gthread_once_t; | |
339 | ||
340 | typedef HANDLE __gthread_mutex_t; | |
341 | ||
342 | #define __GTHREAD_ONCE_INIT {FALSE, -1} | |
343 | #define __GTHREAD_MUTEX_INIT_FUNCTION __gthread_mutex_init_function | |
b8dd27f3 | 344 | #define __GTHREAD_MUTEX_INIT_DEFAULT 0 |
471528fc | 345 | |
c13f265c | 346 | #if __MINGW32_MAJOR_VERSION >= 1 || \ |
347 | (__MINGW32_MAJOR_VERSION == 0 && __MINGW32_MINOR_VERSION > 2) | |
348 | #define MINGW32_SUPPORTS_MT_EH 1 | |
61dcce9c | 349 | #ifdef __cplusplus |
350 | extern "C" { | |
351 | #endif | |
352 | extern int __mingwthr_key_dtor (DWORD, void (*) (void *)); | |
353 | #ifdef __cplusplus | |
354 | } | |
355 | #endif | |
356 | ||
c13f265c | 357 | /* Mingw runtime >= v0.3 provides a magic variable that is set to non-zero |
3cfec666 | 358 | if -mthreads option was specified, or 0 otherwise. This is to get around |
c13f265c | 359 | the lack of weak symbols in PE-COFF. */ |
360 | extern int _CRT_MT; | |
361 | #endif | |
362 | ||
471528fc | 363 | static inline int |
205b5771 | 364 | __gthread_active_p (void) |
471528fc | 365 | { |
c13f265c | 366 | #ifdef MINGW32_SUPPORTS_MT_EH |
367 | return _CRT_MT; | |
368 | #else | |
471528fc | 369 | return 1; |
c13f265c | 370 | #endif |
471528fc | 371 | } |
372 | ||
373 | static inline int | |
205b5771 | 374 | __gthread_once (__gthread_once_t *once, void (*func) (void)) |
471528fc | 375 | { |
376 | if (! __gthread_active_p ()) | |
377 | return -1; | |
378 | else if (once == NULL || func == NULL) | |
379 | return EINVAL; | |
380 | ||
381 | if (! once->done) | |
382 | { | |
383 | if (InterlockedIncrement (&(once->started)) == 0) | |
3cfec666 | 384 | { |
471528fc | 385 | (*func) (); |
386 | once->done = TRUE; | |
387 | } | |
c13f265c | 388 | else |
389 | { | |
3cfec666 | 390 | /* Another thread is currently executing the code, so wait for it |
391 | to finish; yield the CPU in the meantime. If performance | |
392 | does become an issue, the solution is to use an Event that | |
393 | we wait on here (and set above), but that implies a place to | |
394 | create the event before this routine is called. */ | |
c13f265c | 395 | while (! once->done) |
396 | Sleep (0); | |
397 | } | |
471528fc | 398 | } |
3cfec666 | 399 | |
471528fc | 400 | return 0; |
401 | } | |
402 | ||
c13f265c | 403 | /* Windows32 thread local keys don't support destructors; this leads to |
3cfec666 | 404 | leaks, especially in threaded applications making extensive use of |
c13f265c | 405 | C++ EH. Mingw uses a thread-support DLL to work-around this problem. */ |
471528fc | 406 | static inline int |
c13f265c | 407 | __gthread_key_create (__gthread_key_t *key, void (*dtor) (void *)) |
471528fc | 408 | { |
409 | int status = 0; | |
410 | DWORD tls_index = TlsAlloc (); | |
411 | if (tls_index != 0xFFFFFFFF) | |
c13f265c | 412 | { |
413 | *key = tls_index; | |
414 | #ifdef MINGW32_SUPPORTS_MT_EH | |
415 | /* Mingw runtime will run the dtors in reverse order for each thread | |
416 | when the thread exits. */ | |
417 | status = __mingwthr_key_dtor (*key, dtor); | |
418 | #endif | |
419 | } | |
471528fc | 420 | else |
421 | status = (int) GetLastError (); | |
422 | return status; | |
423 | } | |
424 | ||
c13f265c | 425 | /* Currently, this routine is called only for Mingw runtime, and if |
3cfec666 | 426 | -mthreads option is chosen to link in the thread support DLL. */ |
471528fc | 427 | static inline int |
428 | __gthread_key_dtor (__gthread_key_t key, void *ptr) | |
429 | { | |
5a54c45e | 430 | /* Nothing needed. */ |
c13f265c | 431 | return 0; |
471528fc | 432 | } |
433 | ||
471528fc | 434 | static inline int |
435 | __gthread_key_delete (__gthread_key_t key) | |
436 | { | |
437 | return (TlsFree (key) != 0) ? 0 : (int) GetLastError (); | |
438 | } | |
439 | ||
440 | static inline void * | |
441 | __gthread_getspecific (__gthread_key_t key) | |
442 | { | |
bc7da7ad | 443 | DWORD lasterror; |
444 | void *ptr; | |
445 | ||
446 | lasterror = GetLastError(); | |
447 | ||
448 | ptr = TlsGetValue(key); | |
449 | ||
450 | SetLastError( lasterror ); | |
451 | ||
452 | return ptr; | |
471528fc | 453 | } |
454 | ||
455 | static inline int | |
456 | __gthread_setspecific (__gthread_key_t key, const void *ptr) | |
457 | { | |
c13f265c | 458 | return (TlsSetValue (key, (void*) ptr) != 0) ? 0 : (int) GetLastError (); |
471528fc | 459 | } |
460 | ||
461 | static inline void | |
462 | __gthread_mutex_init_function (__gthread_mutex_t *mutex) | |
463 | { | |
3cfec666 | 464 | /* Create unnamed mutex with default security attr and no initial owner. */ |
471528fc | 465 | *mutex = CreateMutex (NULL, 0, NULL); |
466 | } | |
467 | ||
468 | static inline int | |
469 | __gthread_mutex_lock (__gthread_mutex_t *mutex) | |
470 | { | |
471 | int status = 0; | |
472 | ||
473 | if (__gthread_active_p ()) | |
474 | { | |
475 | if (WaitForSingleObject (*mutex, INFINITE) == WAIT_OBJECT_0) | |
476 | status = 0; | |
477 | else | |
478 | status = 1; | |
479 | } | |
480 | return status; | |
481 | } | |
482 | ||
483 | static inline int | |
484 | __gthread_mutex_trylock (__gthread_mutex_t *mutex) | |
485 | { | |
486 | int status = 0; | |
487 | ||
488 | if (__gthread_active_p ()) | |
489 | { | |
490 | if (WaitForSingleObject (*mutex, 0) == WAIT_OBJECT_0) | |
491 | status = 0; | |
492 | else | |
493 | status = 1; | |
494 | } | |
495 | return status; | |
496 | } | |
497 | ||
498 | static inline int | |
499 | __gthread_mutex_unlock (__gthread_mutex_t *mutex) | |
500 | { | |
501 | if (__gthread_active_p ()) | |
502 | return (ReleaseMutex (*mutex) != 0) ? 0 : 1; | |
503 | else | |
504 | return 0; | |
505 | } | |
506 | ||
6319d58e | 507 | #endif /* _LIBOBJC */ |
508 | ||
2a281353 | 509 | #endif /* ! GCC_GTHR_WIN32_H */ |
471528fc | 510 |