platform_system_core/libmemunreachable/Semaphore.h
Colin Cross a9939e9a23 Move libmemunreachable into namespace android
Putting libmemunreachable in the global C++ namespace was an oversight,
move it into namespace android.

Test: m -j checkbuild
Change-Id: I0799906f6463178cb04a719bb4054cad33a50dbe
2017-06-22 10:58:23 -07:00

60 lines
1.4 KiB
C++

/*
* Copyright (C) 2016 The Android Open Source Project
*
* 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.
*/
#ifndef LIBMEMUNREACHABLE_SEMAPHORE_H_
#define LIBMEMUNREACHABLE_SEMAPHORE_H_
#include <chrono>
#include <mutex>
#include "android-base/macros.h"
namespace android {
class Semaphore {
public:
explicit Semaphore(int count = 0) : count_(count) {}
~Semaphore() = default;
void Wait(std::chrono::milliseconds ms) {
std::unique_lock<std::mutex> lk(m_);
cv_.wait_for(lk, ms, [&] {
if (count_ > 0) {
count_--;
return true;
}
return false;
});
}
void Post() {
{
std::lock_guard<std::mutex> lk(m_);
count_++;
}
cv_.notify_one();
}
private:
DISALLOW_COPY_AND_ASSIGN(Semaphore);
int count_;
std::mutex m_;
std::condition_variable cv_;
};
} // namespace android
#endif // LIBMEMUNREACHABLE_SEMAPHORE_H_