cleanup more synchronization code

This commit is contained in:
Nguyen Anh Quynh
2017-01-09 14:05:39 +08:00
parent d7ead1135d
commit 52cb0ba78e
13 changed files with 0 additions and 279 deletions

View File

@ -60,93 +60,6 @@ void qemu_mutex_unlock(QemuMutex *mutex)
LeaveCriticalSection(&mutex->lock);
}
void qemu_cond_init(QemuCond *cond)
{
memset(cond, 0, sizeof(*cond));
cond->sema = CreateSemaphore(NULL, 0, LONG_MAX, NULL);
if (!cond->sema) {
error_exit(GetLastError(), __func__);
}
cond->continue_event = CreateEvent(NULL, /* security */
FALSE, /* auto-reset */
FALSE, /* not signaled */
NULL); /* name */
if (!cond->continue_event) {
error_exit(GetLastError(), __func__);
}
}
void qemu_cond_destroy(QemuCond *cond)
{
BOOL result;
result = CloseHandle(cond->continue_event);
if (!result) {
error_exit(GetLastError(), __func__);
}
cond->continue_event = 0;
result = CloseHandle(cond->sema);
if (!result) {
error_exit(GetLastError(), __func__);
}
cond->sema = 0;
}
void qemu_cond_signal(QemuCond *cond)
{
DWORD result;
/*
* Signal only when there are waiters. cond->waiters is
* incremented by pthread_cond_wait under the external lock,
* so we are safe about that.
*/
if (cond->waiters == 0) {
return;
}
/*
* Waiting threads decrement it outside the external lock, but
* only if another thread is executing pthread_cond_broadcast and
* has the mutex. So, it also cannot be decremented concurrently
* with this particular access.
*/
cond->target = cond->waiters - 1;
result = SignalObjectAndWait(cond->sema, cond->continue_event,
INFINITE, FALSE);
if (result == WAIT_ABANDONED || result == WAIT_FAILED) {
error_exit(GetLastError(), __func__);
}
}
void qemu_cond_broadcast(QemuCond *cond)
{
BOOLEAN result;
/*
* As in pthread_cond_signal, access to cond->waiters and
* cond->target is locked via the external mutex.
*/
if (cond->waiters == 0) {
return;
}
cond->target = 0;
result = ReleaseSemaphore(cond->sema, cond->waiters, NULL);
if (!result) {
error_exit(GetLastError(), __func__);
}
/*
* At this point all waiters continue. Each one takes its
* slice of the semaphore. 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_event, INFINITE);
}
struct QemuThreadData {
/* Passed to win32_start_routine. */
void *(*start_routine)(void *);