tdesktop/Telegram/SourceFiles/base/binary_guard.h

77 lines
1.5 KiB
C++

/*
This file is part of Telegram Desktop,
the official desktop application for the Telegram messaging service.
For license and copyright information please follow this link:
https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
*/
#pragma once
#include "base/algorithm.h"
#include <atomic>
namespace base {
class binary_guard {
public:
binary_guard() = default;
binary_guard(binary_guard &&other);
binary_guard &operator=(binary_guard &&other);
~binary_guard();
bool alive() const;
void kill();
private:
void destroy();
std::atomic<bool> *_bothAlive = nullptr;
friend std::pair<binary_guard, binary_guard> make_binary_guard();
};
inline binary_guard::binary_guard(binary_guard &&other)
: _bothAlive(base::take(other._bothAlive)) {
}
inline binary_guard &binary_guard::operator=(binary_guard &&other) {
if (this != &other) {
destroy();
_bothAlive = base::take(other._bothAlive);
}
return *this;
}
inline binary_guard::~binary_guard() {
destroy();
}
inline bool binary_guard::alive() const {
return _bothAlive && _bothAlive->load();
}
inline void binary_guard::kill() {
destroy();
}
inline void binary_guard::destroy() {
if (const auto both = base::take(_bothAlive)) {
auto old = true;
if (!both->compare_exchange_strong(old, false)) {
delete both;
}
}
}
inline std::pair<binary_guard, binary_guard> make_binary_guard() {
auto result = std::pair<binary_guard, binary_guard>();
result.first._bothAlive
= result.second._bothAlive
= new std::atomic<bool>(true);
return result;
}
} // namespace base