pthread_t pthread_self(void)
{
- pthread_t t = { 0 };
+ pthread_t t = { NULL };
t.tid = GetCurrentThreadId();
return t;
}
-
-int pthread_cond_init(pthread_cond_t *cond, const void *unused)
-{
- cond->waiters = 0;
- cond->was_broadcast = 0;
- InitializeCriticalSection(&cond->waiters_lock);
-
- cond->sema = CreateSemaphore(NULL, 0, LONG_MAX, NULL);
- if (!cond->sema)
- die("CreateSemaphore() failed");
-
- cond->continue_broadcast = CreateEvent(NULL, /* security */
- FALSE, /* auto-reset */
- FALSE, /* not signaled */
- NULL); /* name */
- if (!cond->continue_broadcast)
- die("CreateEvent() failed");
-
- return 0;
-}
-
-int pthread_cond_destroy(pthread_cond_t *cond)
-{
- CloseHandle(cond->sema);
- CloseHandle(cond->continue_broadcast);
- DeleteCriticalSection(&cond->waiters_lock);
- return 0;
-}
-
-int pthread_cond_wait(pthread_cond_t *cond, CRITICAL_SECTION *mutex)
-{
- int last_waiter;
-
- EnterCriticalSection(&cond->waiters_lock);
- cond->waiters++;
- LeaveCriticalSection(&cond->waiters_lock);
-
- /*
- * Unlock external mutex and wait for signal.
- * NOTE: we've held mutex locked long enough to increment
- * waiters count above, so there's no problem with
- * leaving mutex unlocked before we wait on semaphore.
- */
- LeaveCriticalSection(mutex);
-
- /* let's wait - ignore return value */
- WaitForSingleObject(cond->sema, INFINITE);
-
- /*
- * Decrease waiters count. If we are the last waiter, then we must
- * notify the broadcasting thread that it can continue.
- * But if we continued due to cond_signal, we do not have to do that
- * because the signaling thread knows that only one waiter continued.
- */
- EnterCriticalSection(&cond->waiters_lock);
- cond->waiters--;
- last_waiter = cond->was_broadcast && cond->waiters == 0;
- LeaveCriticalSection(&cond->waiters_lock);
-
- if (last_waiter) {
- /*
- * cond_broadcast was issued while mutex was held. This means
- * that all other waiters have continued, but are contending
- * for the mutex at the end of this function because the
- * broadcasting thread did not leave cond_broadcast, yet.
- * (This is so that it can be sure that each waiter has
- * consumed exactly one slice of the semaphor.)
- * The last waiter must tell the broadcasting thread that it
- * can go on.
- */
- SetEvent(cond->continue_broadcast);
- /*
- * Now we go on to contend with all other waiters for
- * the mutex. Auf in den Kampf!
- */
- }
- /* lock external mutex again */
- EnterCriticalSection(mutex);
-
- return 0;
-}
-
-/*
- * IMPORTANT: This implementation requires that pthread_cond_signal
- * is called while the mutex is held that is used in the corresponding
- * pthread_cond_wait calls!
- */
-int pthread_cond_signal(pthread_cond_t *cond)
-{
- int have_waiters;
-
- EnterCriticalSection(&cond->waiters_lock);
- have_waiters = cond->waiters > 0;
- LeaveCriticalSection(&cond->waiters_lock);
-
- /*
- * Signal only when there are waiters
- */
- if (have_waiters)
- return ReleaseSemaphore(cond->sema, 1, NULL) ?
- 0 : err_win_to_posix(GetLastError());
- else
- return 0;
-}
-
-/*
- * DOUBLY IMPORTANT: This implementation requires that pthread_cond_broadcast
- * is called while the mutex is held that is used in the corresponding
- * pthread_cond_wait calls!
- */
-int pthread_cond_broadcast(pthread_cond_t *cond)
-{
- EnterCriticalSection(&cond->waiters_lock);
-
- if ((cond->was_broadcast = cond->waiters > 0)) {
- /* wake up all waiters */
- ReleaseSemaphore(cond->sema, cond->waiters, NULL);
- LeaveCriticalSection(&cond->waiters_lock);
- /*
- * At this point all waiters continue. Each one takes its
- * slice of the semaphor. Now it's our turn to wait: Since
- * the external mutex is held, no thread can leave cond_wait,
- * yet. For this reason, we can be sure that no thread gets
- * a chance to eat *more* than one slice. OTOH, it means
- * that the last waiter must send us a wake-up.
- */
- WaitForSingleObject(cond->continue_broadcast, INFINITE);
- /*
- * Since the external mutex is held, no thread can enter
- * cond_wait, and, hence, it is safe to reset this flag
- * without cond->waiters_lock held.
- */
- cond->was_broadcast = 0;
- } else {
- LeaveCriticalSection(&cond->waiters_lock);
- }
- return 0;
-}