libcruft-util/thread/flag.hpp

40 lines
1.0 KiB
C++

/*
* 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.
*
* Copyright 2018 Danny Robson <danny@nerdcruft.net>
*/
#ifndef CRUFT_UTIL_THREAD_FLAG_HPP
#define CRUFT_UTIL_THREAD_FLAG_HPP
#include <atomic>
namespace util::thread {
/// a fire-once event that users can wait upon. if already fired then
/// waiting will be a noop.
class flag {
public:
flag ();
void wait (void);
int notify (void);
int notify (int);
private:
std::atomic<int> value;
};
};
#endif