1 /* Copyright (C) 2010-2018 The RetroArch team
2 *
3 * ---------------------------------------------------------------------------------------
4 * The following license statement only applies to this file (rthreads.c).
5 * ---------------------------------------------------------------------------------------
6 *
7 * Permission is hereby granted, free of charge,
8 * to any person obtaining a copy of this software and associated documentation files (the "Software"),
9 * to deal in the Software without restriction, including without limitation the rights to
10 * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software,
11 * and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
12 *
13 * The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
16 * INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
18 * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
19 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
20 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
21 */
22
23 #ifdef __unix__
24 #ifndef __sun__
25 #define _POSIX_C_SOURCE 199309
26 #endif
27 #endif
28
29 #include <stdlib.h>
30 #include <string.h>
31
32 #include <boolean.h>
33 #include <rthreads/rthreads.h>
34
35 /* with RETRO_WIN32_USE_PTHREADS, pthreads can be used even on win32. Maybe only supported in MSVC>=2005 */
36
37 #if defined(_WIN32) && !defined(RETRO_WIN32_USE_PTHREADS)
38 #define USE_WIN32_THREADS
39 #ifdef _XBOX
40 #include <xtl.h>
41 #else
42 #define WIN32_LEAN_AND_MEAN
43 #ifndef _WIN32_WINNT
44 #define _WIN32_WINNT 0x0500 /*_WIN32_WINNT_WIN2K */
45 #endif
46 #include <windows.h>
47 #include <mmsystem.h>
48 #endif
49 #elif defined(GEKKO)
50 #include "gx_pthread.h"
51 #elif defined(_3DS)
52 #include "ctr_pthread.h"
53 #else
54 #include <pthread.h>
55 #include <time.h>
56 #endif
57
58 #if defined(VITA) || defined(BSD) || defined(ORBIS)
59 #include <sys/time.h>
60 #endif
61
62 #ifdef __MACH__
63 #include <mach/clock.h>
64 #include <mach/mach.h>
65 #endif
66
67 struct thread_data
68 {
69 void (*func)(void*);
70 void *userdata;
71 };
72
73 struct sthread
74 {
75 #ifdef USE_WIN32_THREADS
76 HANDLE thread;
77 DWORD id;
78 #else
79 pthread_t id;
80 #endif
81 };
82
83 struct slock
84 {
85 #ifdef USE_WIN32_THREADS
86 CRITICAL_SECTION lock;
87 #else
88 pthread_mutex_t lock;
89 #endif
90 };
91
92 #ifdef USE_WIN32_THREADS
93 /* The syntax we'll use is mind-bending unless we use a struct. Plus, we might want to store more info later */
94 /* This will be used as a linked list immplementing a queue of waiting threads */
95 struct QueueEntry
96 {
97 struct QueueEntry *next;
98 };
99 #endif
100
101 struct scond
102 {
103 #ifdef USE_WIN32_THREADS
104 /* With this implementation of scond, we don't have any way of waking
105 * (or even identifying) specific threads
106 * But we need to wake them in the order indicated by the queue.
107 * This potato token will get get passed around every waiter.
108 * The bearer can test whether he's next, and hold onto the potato if he is.
109 * When he's done he can then put it back into play to progress
110 * the queue further */
111 HANDLE hot_potato;
112
113 /* The primary signalled event. Hot potatoes are passed until this is set. */
114 HANDLE event;
115
116 /* the head of the queue; NULL if queue is empty */
117 struct QueueEntry *head;
118
119 /* equivalent to the queue length */
120 int waiters;
121
122 /* how many waiters in the queue have been conceptually wakened by signals
123 * (even if we haven't managed to actually wake them yet) */
124 int wakens;
125
126 /* used to control access to this scond, in case the user fails */
127 CRITICAL_SECTION cs;
128
129 #else
130 pthread_cond_t cond;
131 #endif
132 };
133
134 #ifdef USE_WIN32_THREADS
thread_wrap(void * data_)135 static DWORD CALLBACK thread_wrap(void *data_)
136 #else
137 static void *thread_wrap(void *data_)
138 #endif
139 {
140 struct thread_data *data = (struct thread_data*)data_;
141 if (!data)
142 return 0;
143 data->func(data->userdata);
144 free(data);
145 return 0;
146 }
147
148 /**
149 * sthread_create:
150 * @start_routine : thread entry callback function
151 * @userdata : pointer to userdata that will be made
152 * available in thread entry callback function
153 *
154 * Create a new thread.
155 *
156 * Returns: pointer to new thread if successful, otherwise NULL.
157 */
sthread_create(void (* thread_func)(void *),void * userdata)158 sthread_t *sthread_create(void (*thread_func)(void*), void *userdata)
159 {
160 return sthread_create_with_priority(thread_func, userdata, 0);
161 }
162
163 /* TODO/FIXME - this needs to be implemented for Switch/3DS */
164 #if !defined(SWITCH) && !defined(USE_WIN32_THREADS) && !defined(_3DS) && !defined(GEKKO) && !defined(__HAIKU__)
165 #define HAVE_THREAD_ATTR
166 #endif
167
168 /**
169 * sthread_create_with_priority:
170 * @start_routine : thread entry callback function
171 * @userdata : pointer to userdata that will be made
172 * available in thread entry callback function
173 * @thread_priority : thread priority hint value from [1-100]
174 *
175 * Create a new thread. It is possible for the caller to give a hint
176 * for the thread's priority from [1-100]. Any passed in @thread_priority
177 * values that are outside of this range will cause sthread_create() to
178 * create a new thread using the operating system's default thread
179 * priority.
180 *
181 * Returns: pointer to new thread if successful, otherwise NULL.
182 */
sthread_create_with_priority(void (* thread_func)(void *),void * userdata,int thread_priority)183 sthread_t *sthread_create_with_priority(void (*thread_func)(void*), void *userdata, int thread_priority)
184 {
185 #ifdef HAVE_THREAD_ATTR
186 pthread_attr_t thread_attr;
187 bool thread_attr_needed = false;
188 #endif
189 bool thread_created = false;
190 struct thread_data *data = NULL;
191 sthread_t *thread = (sthread_t*)calloc(1, sizeof(*thread));
192
193 if (!thread)
194 return NULL;
195
196 data = (struct thread_data*)calloc(1, sizeof(*data));
197 if (!data)
198 goto error;
199
200 data->func = thread_func;
201 data->userdata = userdata;
202
203 #ifdef USE_WIN32_THREADS
204 thread->thread = CreateThread(NULL, 0, thread_wrap, data, 0, &thread->id);
205 thread_created = !!thread->thread;
206 #else
207
208 #ifdef HAVE_THREAD_ATTR
209 pthread_attr_init(&thread_attr);
210
211 if ( (thread_priority >= 1) && (thread_priority <= 100) )
212 {
213 struct sched_param sp;
214 memset(&sp, 0, sizeof(struct sched_param));
215 sp.sched_priority = thread_priority;
216 pthread_attr_setschedpolicy(&thread_attr, SCHED_RR);
217 pthread_attr_setschedparam(&thread_attr, &sp);
218
219 thread_attr_needed = true;
220 }
221 #endif
222
223 #if defined(VITA)
224 pthread_attr_setstacksize(&thread_attr , 0x10000 );
225 thread_attr_needed = true;
226 #endif
227
228 #ifdef HAVE_THREAD_ATTR
229 if (thread_attr_needed)
230 thread_created = pthread_create(&thread->id, &thread_attr, thread_wrap, data) == 0;
231 else
232 #endif
233 thread_created = pthread_create(&thread->id, NULL, thread_wrap, data) == 0;
234
235 #ifdef HAVE_THREAD_ATTR
236 pthread_attr_destroy(&thread_attr);
237 #endif
238 #endif
239
240 if (thread_created)
241 return thread;
242
243 error:
244 if (data)
245 free(data);
246 free(thread);
247 return NULL;
248 }
249
250 /**
251 * sthread_detach:
252 * @thread : pointer to thread object
253 *
254 * Detach a thread. When a detached thread terminates, its
255 * resources are automatically released back to the system
256 * without the need for another thread to join with the
257 * terminated thread.
258 *
259 * Returns: 0 on success, otherwise it returns a non-zero error number.
260 */
sthread_detach(sthread_t * thread)261 int sthread_detach(sthread_t *thread)
262 {
263 #ifdef USE_WIN32_THREADS
264 CloseHandle(thread->thread);
265 free(thread);
266 return 0;
267 #else
268 return pthread_detach(thread->id);
269 #endif
270 }
271
272 /**
273 * sthread_join:
274 * @thread : pointer to thread object
275 *
276 * Join with a terminated thread. Waits for the thread specified by
277 * @thread to terminate. If that thread has already terminated, then
278 * it will return immediately. The thread specified by @thread must
279 * be joinable.
280 *
281 * Returns: 0 on success, otherwise it returns a non-zero error number.
282 */
sthread_join(sthread_t * thread)283 void sthread_join(sthread_t *thread)
284 {
285 if (!thread)
286 return;
287 #ifdef USE_WIN32_THREADS
288 WaitForSingleObject(thread->thread, INFINITE);
289 CloseHandle(thread->thread);
290 #else
291 pthread_join(thread->id, NULL);
292 #endif
293 free(thread);
294 }
295
296 /**
297 * sthread_isself:
298 * @thread : pointer to thread object
299 *
300 * Returns: true (1) if calling thread is the specified thread
301 */
sthread_isself(sthread_t * thread)302 bool sthread_isself(sthread_t *thread)
303 {
304 /* This thread can't possibly be a null thread */
305 if (!thread)
306 return false;
307
308 #ifdef USE_WIN32_THREADS
309 return GetCurrentThreadId() == thread->id;
310 #else
311 return pthread_equal(pthread_self(),thread->id);
312 #endif
313 }
314
315 /**
316 * slock_new:
317 *
318 * Create and initialize a new mutex. Must be manually
319 * freed.
320 *
321 * Returns: pointer to a new mutex if successful, otherwise NULL.
322 **/
slock_new(void)323 slock_t *slock_new(void)
324 {
325 bool mutex_created = false;
326 slock_t *lock = (slock_t*)calloc(1, sizeof(*lock));
327 if (!lock)
328 return NULL;
329
330 #ifdef USE_WIN32_THREADS
331 InitializeCriticalSection(&lock->lock);
332 mutex_created = true;
333 #else
334 mutex_created = (pthread_mutex_init(&lock->lock, NULL) == 0);
335 #endif
336
337 if (!mutex_created)
338 goto error;
339
340 return lock;
341
342 error:
343 free(lock);
344 return NULL;
345 }
346
347 /**
348 * slock_free:
349 * @lock : pointer to mutex object
350 *
351 * Frees a mutex.
352 **/
slock_free(slock_t * lock)353 void slock_free(slock_t *lock)
354 {
355 if (!lock)
356 return;
357
358 #ifdef USE_WIN32_THREADS
359 DeleteCriticalSection(&lock->lock);
360 #else
361 pthread_mutex_destroy(&lock->lock);
362 #endif
363 free(lock);
364 }
365
366 /**
367 * slock_lock:
368 * @lock : pointer to mutex object
369 *
370 * Locks a mutex. If a mutex is already locked by
371 * another thread, the calling thread shall block until
372 * the mutex becomes available.
373 **/
slock_lock(slock_t * lock)374 void slock_lock(slock_t *lock)
375 {
376 if (!lock)
377 return;
378 #ifdef USE_WIN32_THREADS
379 EnterCriticalSection(&lock->lock);
380 #else
381 pthread_mutex_lock(&lock->lock);
382 #endif
383 }
384
385 /**
386 * slock_try_lock:
387 * @lock : pointer to mutex object
388 *
389 * Attempts to lock a mutex. If a mutex is already locked by
390 * another thread, return false. If the lock is acquired, return true.
391 **/
slock_try_lock(slock_t * lock)392 bool slock_try_lock(slock_t *lock)
393 {
394 if (!lock)
395 return false;
396 #ifdef USE_WIN32_THREADS
397 return TryEnterCriticalSection(&lock->lock);
398 #else
399 return pthread_mutex_trylock(&lock->lock)==0;
400 #endif
401 }
402
403 /**
404 * slock_unlock:
405 * @lock : pointer to mutex object
406 *
407 * Unlocks a mutex.
408 **/
slock_unlock(slock_t * lock)409 void slock_unlock(slock_t *lock)
410 {
411 if (!lock)
412 return;
413 #ifdef USE_WIN32_THREADS
414 LeaveCriticalSection(&lock->lock);
415 #else
416 pthread_mutex_unlock(&lock->lock);
417 #endif
418 }
419
420 /**
421 * scond_new:
422 *
423 * Creates and initializes a condition variable. Must
424 * be manually freed.
425 *
426 * Returns: pointer to new condition variable on success,
427 * otherwise NULL.
428 **/
scond_new(void)429 scond_t *scond_new(void)
430 {
431 scond_t *cond = (scond_t*)calloc(1, sizeof(*cond));
432
433 if (!cond)
434 return NULL;
435
436 #ifdef USE_WIN32_THREADS
437
438 /* This is very complex because recreating condition variable semantics
439 * with Win32 parts is not easy.
440 *
441 * The main problem is that a condition variable can't be used to
442 * "pre-wake" a thread (it will get wakened only after it's waited).
443 *
444 * Whereas a win32 event can pre-wake a thread (the event will be set
445 * in advance, so a 'waiter' won't even have to wait on it).
446 *
447 * Keep in mind a condition variable can apparently pre-wake a thread,
448 * insofar as spurious wakeups are always possible,
449 * but nobody will be expecting this and it does not need to be simulated.
450 *
451 * Moreover, we won't be doing this, because it counts as a spurious wakeup
452 * -- someone else with a genuine claim must get wakened, in any case.
453 *
454 * Therefore we choose to wake only one of the correct waiting threads.
455 * So at the very least, we need to do something clever. But there's
456 * bigger problems.
457 * We don't even have a straightforward way in win32 to satisfy
458 * pthread_cond_wait's atomicity requirement. The bulk of this
459 * algorithm is solving that.
460 *
461 * Note: We might could simplify this using vista+ condition variables,
462 * but we wanted an XP compatible solution. */
463 cond->event = CreateEvent(NULL, FALSE, FALSE, NULL);
464 if (!cond->event) goto error;
465 cond->hot_potato = CreateEvent(NULL, FALSE, FALSE, NULL);
466 if (!cond->hot_potato)
467 {
468 CloseHandle(cond->event);
469 goto error;
470 }
471
472 InitializeCriticalSection(&cond->cs);
473 cond->waiters = cond->wakens = 0;
474 cond->head = NULL;
475
476 #else
477 if (pthread_cond_init(&cond->cond, NULL) != 0)
478 goto error;
479 #endif
480
481 return cond;
482
483 error:
484 free(cond);
485 return NULL;
486 }
487
488 /**
489 * scond_free:
490 * @cond : pointer to condition variable object
491 *
492 * Frees a condition variable.
493 **/
scond_free(scond_t * cond)494 void scond_free(scond_t *cond)
495 {
496 if (!cond)
497 return;
498
499 #ifdef USE_WIN32_THREADS
500 CloseHandle(cond->event);
501 CloseHandle(cond->hot_potato);
502 DeleteCriticalSection(&cond->cs);
503 #else
504 pthread_cond_destroy(&cond->cond);
505 #endif
506 free(cond);
507 }
508
509 #ifdef USE_WIN32_THREADS
_scond_wait_win32(scond_t * cond,slock_t * lock,DWORD dwMilliseconds)510 static bool _scond_wait_win32(scond_t *cond, slock_t *lock, DWORD dwMilliseconds)
511 {
512 struct QueueEntry myentry;
513 struct QueueEntry **ptr;
514
515 #if _WIN32_WINNT >= 0x0500 || defined(_XBOX)
516 static LARGE_INTEGER performanceCounterFrequency;
517 LARGE_INTEGER tsBegin;
518 static bool first_init = true;
519 #else
520 static bool beginPeriod = false;
521 DWORD tsBegin;
522 #endif
523
524 DWORD waitResult;
525 DWORD dwFinalTimeout = dwMilliseconds; /* Careful! in case we begin in the head,
526 we don't do the hot potato stuff,
527 so this timeout needs presetting. */
528
529 /* Reminder: `lock` is held before this is called. */
530 /* however, someone else may have called scond_signal without the lock. soo... */
531 EnterCriticalSection(&cond->cs);
532
533 /* since this library is meant for realtime game software
534 * I have no problem setting this to 1 and forgetting about it. */
535 #if _WIN32_WINNT >= 0x0500 || defined(_XBOX)
536 if (first_init)
537 {
538 performanceCounterFrequency.QuadPart = 0;
539 first_init = false;
540 }
541
542 if (performanceCounterFrequency.QuadPart == 0)
543 {
544 QueryPerformanceFrequency(&performanceCounterFrequency);
545 }
546 #else
547 if (!beginPeriod)
548 {
549 beginPeriod = true;
550 timeBeginPeriod(1);
551 }
552 #endif
553
554 /* Now we can take a good timestamp for use in faking the timeout ourselves. */
555 /* But don't bother unless we need to (to save a little time) */
556 if (dwMilliseconds != INFINITE)
557 #if _WIN32_WINNT >= 0x0500 || defined(_XBOX)
558 QueryPerformanceCounter(&tsBegin);
559 #else
560 tsBegin = timeGetTime();
561 #endif
562
563 /* add ourselves to a queue of waiting threads */
564 ptr = &cond->head;
565
566 /* walk to the end of the linked list */
567 while (*ptr)
568 ptr = &((*ptr)->next);
569
570 *ptr = &myentry;
571 myentry.next = NULL;
572
573 cond->waiters++;
574
575 /* now the conceptual lock release and condition block are supposed to be atomic.
576 * we can't do that in Windows, but we can simulate the effects by using
577 * the queue, by the following analysis:
578 * What happens if they aren't atomic?
579 *
580 * 1. a signaller can rush in and signal, expecting a waiter to get it;
581 * but the waiter wouldn't, because he isn't blocked yet.
582 * Solution: Win32 events make this easy. The event will sit there enabled
583 *
584 * 2. a signaller can rush in and signal, and then turn right around and wait.
585 * Solution: the signaller will get queued behind the waiter, who's
586 * enqueued before he releases the mutex. */
587
588 /* It's my turn if I'm the head of the queue.
589 * Check to see if it's my turn. */
590 while (cond->head != &myentry)
591 {
592 /* It isn't my turn: */
593 DWORD timeout = INFINITE;
594
595 /* As long as someone is even going to be able to wake up
596 * when they receive the potato, keep it going round. */
597 if (cond->wakens > 0)
598 SetEvent(cond->hot_potato);
599
600 /* Assess the remaining timeout time */
601 if (dwMilliseconds != INFINITE)
602 {
603 #if _WIN32_WINNT >= 0x0500 || defined(_XBOX)
604 LARGE_INTEGER now;
605 LONGLONG elapsed;
606
607 QueryPerformanceCounter(&now);
608 elapsed = now.QuadPart - tsBegin.QuadPart;
609 elapsed *= 1000;
610 elapsed /= performanceCounterFrequency.QuadPart;
611 #else
612 DWORD now = timeGetTime();
613 DWORD elapsed = now - tsBegin;
614 #endif
615
616 /* Try one last time with a zero timeout (keeps the code simpler) */
617 if (elapsed > dwMilliseconds)
618 elapsed = dwMilliseconds;
619
620 timeout = dwMilliseconds - elapsed;
621 }
622
623 /* Let someone else go */
624 LeaveCriticalSection(&lock->lock);
625 LeaveCriticalSection(&cond->cs);
626
627 /* Wait a while to catch the hot potato..
628 * someone else should get a chance to go */
629 /* After all, it isn't my turn (and it must be someone else's) */
630 Sleep(0);
631 waitResult = WaitForSingleObject(cond->hot_potato, timeout);
632
633 /* I should come out of here with the main lock taken */
634 EnterCriticalSection(&lock->lock);
635 EnterCriticalSection(&cond->cs);
636
637 if (waitResult == WAIT_TIMEOUT)
638 {
639 /* Out of time! Now, let's think about this. I do have the potato now--
640 * maybe it's my turn, and I have the event?
641 * If that's the case, I could proceed right now without aborting
642 * due to timeout.
643 *
644 * However.. I DID wait a real long time. The caller was willing
645 * to wait that long.
646 *
647 * I choose to give him one last chance with a zero timeout
648 * in the next step
649 */
650 if (cond->head == &myentry)
651 {
652 dwFinalTimeout = 0;
653 break;
654 }
655 else
656 {
657 /* It's not our turn and we're out of time. Give up.
658 * Remove ourself from the queue and bail. */
659 struct QueueEntry* curr = cond->head;
660
661 while (curr->next != &myentry)
662 curr = curr->next;
663 curr->next = myentry.next;
664 cond->waiters--;
665 LeaveCriticalSection(&cond->cs);
666 return false;
667 }
668 }
669
670 }
671
672 /* It's my turn now -- and I hold the potato */
673
674 /* I still have the main lock, in any case */
675 /* I need to release it so that someone can set the event */
676 LeaveCriticalSection(&lock->lock);
677 LeaveCriticalSection(&cond->cs);
678
679 /* Wait for someone to actually signal this condition */
680 /* We're the only waiter waiting on the event right now -- everyone else
681 * is waiting on something different */
682 waitResult = WaitForSingleObject(cond->event, dwFinalTimeout);
683
684 /* Take the main lock so we can do work. Nobody else waits on this lock
685 * for very long, so even though it's GO TIME we won't have to wait long */
686 EnterCriticalSection(&lock->lock);
687 EnterCriticalSection(&cond->cs);
688
689 /* Remove ourselves from the queue */
690 cond->head = myentry.next;
691 cond->waiters--;
692
693 if (waitResult == WAIT_TIMEOUT)
694 {
695 /* Oops! ran out of time in the final wait. Just bail. */
696 LeaveCriticalSection(&cond->cs);
697 return false;
698 }
699
700 /* If any other wakenings are pending, go ahead and set it up */
701 /* There may actually be no waiters. That's OK. The first waiter will come in,
702 * find it's his turn, and immediately get the signaled event */
703 cond->wakens--;
704 if (cond->wakens > 0)
705 {
706 SetEvent(cond->event);
707
708 /* Progress the queue: Put the hot potato back into play. It'll be
709 * tossed around until next in line gets it */
710 SetEvent(cond->hot_potato);
711 }
712
713 LeaveCriticalSection(&cond->cs);
714 return true;
715 }
716 #endif
717
718 /**
719 * scond_wait:
720 * @cond : pointer to condition variable object
721 * @lock : pointer to mutex object
722 *
723 * Block on a condition variable (i.e. wait on a condition).
724 **/
scond_wait(scond_t * cond,slock_t * lock)725 void scond_wait(scond_t *cond, slock_t *lock)
726 {
727 #ifdef USE_WIN32_THREADS
728 _scond_wait_win32(cond, lock, INFINITE);
729 #else
730 pthread_cond_wait(&cond->cond, &lock->lock);
731 #endif
732 }
733
734 /**
735 * scond_broadcast:
736 * @cond : pointer to condition variable object
737 *
738 * Broadcast a condition. Unblocks all threads currently blocked
739 * on the specified condition variable @cond.
740 **/
scond_broadcast(scond_t * cond)741 int scond_broadcast(scond_t *cond)
742 {
743 #ifdef USE_WIN32_THREADS
744 /* remember: we currently have mutex */
745 if (cond->waiters == 0)
746 return 0;
747
748 /* awaken everything which is currently queued up */
749 if (cond->wakens == 0)
750 SetEvent(cond->event);
751 cond->wakens = cond->waiters;
752
753 /* Since there is now at least one pending waken, the potato must be in play */
754 SetEvent(cond->hot_potato);
755
756 return 0;
757 #else
758 return pthread_cond_broadcast(&cond->cond);
759 #endif
760 }
761
762 /**
763 * scond_signal:
764 * @cond : pointer to condition variable object
765 *
766 * Signal a condition. Unblocks at least one of the threads currently blocked
767 * on the specified condition variable @cond.
768 **/
scond_signal(scond_t * cond)769 void scond_signal(scond_t *cond)
770 {
771 #ifdef USE_WIN32_THREADS
772
773 /* Unfortunately, pthread_cond_signal does not require that the
774 * lock be held in advance */
775 /* To avoid stomping on the condvar from other threads, we need
776 * to control access to it with this */
777 EnterCriticalSection(&cond->cs);
778
779 /* remember: we currently have mutex */
780 if (cond->waiters == 0)
781 {
782 LeaveCriticalSection(&cond->cs);
783 return;
784 }
785
786 /* wake up the next thing in the queue */
787 if (cond->wakens == 0)
788 SetEvent(cond->event);
789
790 cond->wakens++;
791
792 /* The data structure is done being modified.. I think we can leave the CS now.
793 * This would prevent some other thread from receiving the hot potato and then
794 * immediately stalling for the critical section.
795 * But remember, we were trying to replicate a semantic where this entire
796 * scond_signal call was controlled (by the user) by a lock.
797 * So in case there's trouble with this, we can move it after SetEvent() */
798 LeaveCriticalSection(&cond->cs);
799
800 /* Since there is now at least one pending waken, the potato must be in play */
801 SetEvent(cond->hot_potato);
802
803 #else
804 pthread_cond_signal(&cond->cond);
805 #endif
806 }
807
808 /**
809 * scond_wait_timeout:
810 * @cond : pointer to condition variable object
811 * @lock : pointer to mutex object
812 * @timeout_us : timeout (in microseconds)
813 *
814 * Try to block on a condition variable (i.e. wait on a condition) until
815 * @timeout_us elapses.
816 *
817 * Returns: false (0) if timeout elapses before condition variable is
818 * signaled or broadcast, otherwise true (1).
819 **/
scond_wait_timeout(scond_t * cond,slock_t * lock,int64_t timeout_us)820 bool scond_wait_timeout(scond_t *cond, slock_t *lock, int64_t timeout_us)
821 {
822 #ifdef USE_WIN32_THREADS
823 /* How to convert a microsecond (us) timeout to millisecond (ms)?
824 *
825 * Someone asking for a 0 timeout clearly wants immediate timeout.
826 * Someone asking for a 1 timeout clearly wants an actual timeout
827 * of the minimum length */
828
829 /* Someone asking for 1000 or 1001 timeout shouldn't
830 * accidentally get 2ms. */
831 DWORD dwMilliseconds = timeout_us/1000;
832
833 /* The implementation of a 0 timeout here with pthreads is sketchy.
834 * It isn't clear what happens if pthread_cond_timedwait is called with NOW.
835 * Moreover, it is possible that this thread gets pre-empted after the
836 * clock_gettime but before the pthread_cond_timedwait.
837 * In order to help smoke out problems caused by this strange usage,
838 * let's treat a 0 timeout as always timing out.
839 */
840 if (timeout_us == 0)
841 return false;
842 else if (timeout_us < 1000)
843 dwMilliseconds = 1;
844
845 return _scond_wait_win32(cond,lock,dwMilliseconds);
846 #else
847 int ret;
848 int64_t seconds, remainder;
849 struct timespec now = {0};
850
851 #ifdef __MACH__
852 /* OSX doesn't have clock_gettime. */
853 clock_serv_t cclock;
854 mach_timespec_t mts;
855
856 host_get_clock_service(mach_host_self(), CALENDAR_CLOCK, &cclock);
857 clock_get_time(cclock, &mts);
858 mach_port_deallocate(mach_task_self(), cclock);
859 now.tv_sec = mts.tv_sec;
860 now.tv_nsec = mts.tv_nsec;
861 #elif defined(PS2)
862 int tickms = clock();
863 now.tv_sec = tickms/1000;
864 now.tv_nsec = tickms * 1000;
865 #elif defined(__mips__) || defined(VITA) || defined(_3DS)
866 struct timeval tm;
867
868 gettimeofday(&tm, NULL);
869 now.tv_sec = tm.tv_sec;
870 now.tv_nsec = tm.tv_usec * 1000;
871 #elif defined(RETRO_WIN32_USE_PTHREADS)
872 _ftime64_s(&now);
873 #elif !defined(GEKKO)
874 /* timeout on libogc is duration, not end time. */
875 clock_gettime(CLOCK_REALTIME, &now);
876 #endif
877
878 seconds = timeout_us / INT64_C(1000000);
879 remainder = timeout_us % INT64_C(1000000);
880
881 now.tv_sec += seconds;
882 now.tv_nsec += remainder * INT64_C(1000);
883
884 if (now.tv_nsec > 1000000000)
885 {
886 now.tv_nsec -= 1000000000;
887 now.tv_sec += 1;
888 }
889
890 ret = pthread_cond_timedwait(&cond->cond, &lock->lock, &now);
891 return (ret == 0);
892 #endif
893 }
894
895 #ifdef HAVE_THREAD_STORAGE
sthread_tls_create(sthread_tls_t * tls)896 bool sthread_tls_create(sthread_tls_t *tls)
897 {
898 #ifdef USE_WIN32_THREADS
899 return (*tls = TlsAlloc()) != TLS_OUT_OF_INDEXES;
900 #else
901 return pthread_key_create((pthread_key_t*)tls, NULL) == 0;
902 #endif
903 }
904
sthread_tls_delete(sthread_tls_t * tls)905 bool sthread_tls_delete(sthread_tls_t *tls)
906 {
907 #ifdef USE_WIN32_THREADS
908 return TlsFree(*tls) != 0;
909 #else
910 return pthread_key_delete(*tls) == 0;
911 #endif
912 }
913
sthread_tls_get(sthread_tls_t * tls)914 void *sthread_tls_get(sthread_tls_t *tls)
915 {
916 #ifdef USE_WIN32_THREADS
917 return TlsGetValue(*tls);
918 #else
919 return pthread_getspecific(*tls);
920 #endif
921 }
922
sthread_tls_set(sthread_tls_t * tls,const void * data)923 bool sthread_tls_set(sthread_tls_t *tls, const void *data)
924 {
925 #ifdef USE_WIN32_THREADS
926 return TlsSetValue(*tls, (void*)data) != 0;
927 #else
928 return pthread_setspecific(*tls, data) == 0;
929 #endif
930 }
931 #endif
932