97 linhas
1.9 KiB
C++
97 linhas
1.9 KiB
C++
|
//
|
||
|
|
// Copyright (c) 2008,2010 Advanced Micro Devices, Inc. All rights reserved.
|
||
|
|
//
|
||
|
|
|
||
|
|
#include "thread/semaphore.hpp"
|
||
|
|
#include "thread/atomic.hpp"
|
||
|
|
#include "thread/thread.hpp"
|
||
|
|
|
||
|
|
#if defined(_WIN32) || defined(__CYGWIN__)
|
||
|
|
# include <windows.h>
|
||
|
|
#else // !_WIN32
|
||
|
|
# include <semaphore.h>
|
||
|
|
# include <errno.h>
|
||
|
|
#endif // !_WIN32
|
||
|
|
|
||
|
|
namespace amd {
|
||
|
|
|
||
|
|
Semaphore::Semaphore()
|
||
|
|
: state_(0)
|
||
|
|
{
|
||
|
|
#ifdef _WIN32
|
||
|
|
handle_ = static_cast<void*>(CreateSemaphore(NULL, 0, LONG_MAX, NULL));
|
||
|
|
assert(handle_ != NULL && "CreateSemaphore failed");
|
||
|
|
#else // !_WIN32
|
||
|
|
if (sem_init(&sem_, 0, 0) != 0) {
|
||
|
|
fatal("sem_init() failed");
|
||
|
|
}
|
||
|
|
#endif // !_WIN32
|
||
|
|
}
|
||
|
|
|
||
|
|
Semaphore::~Semaphore()
|
||
|
|
{
|
||
|
|
#ifdef _WIN32
|
||
|
|
if (!CloseHandle(static_cast<HANDLE>(handle_))) {
|
||
|
|
fatal("CloseHandle() failed");
|
||
|
|
}
|
||
|
|
#else // !_WIN32
|
||
|
|
if (sem_destroy(&sem_) != 0) {
|
||
|
|
fatal("sem_destroy() failed");
|
||
|
|
}
|
||
|
|
#endif // !WIN32
|
||
|
|
}
|
||
|
|
|
||
|
|
void
|
||
|
|
Semaphore::post()
|
||
|
|
{
|
||
|
|
int state;
|
||
|
|
while (true) {
|
||
|
|
state = state_;
|
||
|
|
if (state > 0) {
|
||
|
|
// Do a load acquire.
|
||
|
|
MemoryOrder::fence();
|
||
|
|
if (state == state_) {
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
continue;
|
||
|
|
}
|
||
|
|
if (state_.compareAndSet(state, state+1)) {
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
if (state < 0) {
|
||
|
|
// We have threads waiting on this event.
|
||
|
|
#ifdef _WIN32
|
||
|
|
ReleaseSemaphore(static_cast<HANDLE>(handle_), 1, NULL);
|
||
|
|
#else // !_WIN32
|
||
|
|
if (0 != sem_post(&sem_)) {
|
||
|
|
fatal("sem_post() failed");
|
||
|
|
}
|
||
|
|
#endif // !_WIN32
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
void
|
||
|
|
Semaphore::wait()
|
||
|
|
{
|
||
|
|
if (state_-- > 0) {
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
|
||
|
|
#ifdef _WIN32
|
||
|
|
if (WAIT_OBJECT_0 != WaitForSingleObject(
|
||
|
|
static_cast<HANDLE>(handle_), INFINITE)) {
|
||
|
|
fatal("WaitForSingleObject failed");
|
||
|
|
}
|
||
|
|
#else // !_WIN32
|
||
|
|
while (0 != sem_wait(&sem_)) {
|
||
|
|
if (EINTR != errno) {
|
||
|
|
fatal("sem_wait() failed");
|
||
|
|
}
|
||
|
|
}
|
||
|
|
#endif // !_WIN32
|
||
|
|
}
|
||
|
|
|
||
|
|
} // namespace amd
|