// Copyright 2014 The Crashpad Authors. All rights reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#include "util/synchronization/semaphore.h"

#include <limits>

#include "base/logging.h"
#include "base/posix/eintr_wrapper.h"

namespace crashpad {

#if defined(OS_MACOSX)

Semaphore::Semaphore(int value)
    : semaphore_(dispatch_semaphore_create(value)) {
  CHECK(semaphore_) << "dispatch_semaphore_create";
}

Semaphore::~Semaphore() {
  dispatch_release(semaphore_);
}

void Semaphore::Wait() {
  CHECK_EQ(dispatch_semaphore_wait(semaphore_, DISPATCH_TIME_FOREVER), 0);
}

void Semaphore::Signal() {
  dispatch_semaphore_signal(semaphore_);
}

#elif defined(OS_WIN)

Semaphore::Semaphore(int value)
    : semaphore_(CreateSemaphore(nullptr,
                                 value,
                                 std::numeric_limits<LONG>::max(),
                                 nullptr)) {
  PCHECK(semaphore_) << "CreateSemaphore";
}

Semaphore::~Semaphore() {
  PCHECK(CloseHandle(semaphore_));
}

void Semaphore::Wait() {
  PCHECK(WaitForSingleObject(semaphore_, INFINITE) == WAIT_OBJECT_0);
}

void Semaphore::Signal() {
  PCHECK(ReleaseSemaphore(semaphore_, 1, nullptr));
}

#else

Semaphore::Semaphore(int value) {
  PCHECK(sem_init(&semaphore_, 0, value) == 0) << "sem_init";
}

Semaphore::~Semaphore() {
  PCHECK(sem_destroy(&semaphore_)) << "sem_destroy";
}

void Semaphore::Wait() {
  PCHECK(HANDLE_EINTR(sem_wait(&semaphore_))) << "sem_wait";
}

void Semaphore::Signal() {
  PCHECK(sem_post(&semaphore_)) << "sem_post";
}

#endif

}  // namespace crashpad