You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
84 lines
2.3 KiB
C++
84 lines
2.3 KiB
C++
/*
|
|
* ttas_spin_mutex.hpp
|
|
*
|
|
* MIT License
|
|
*
|
|
* Copyright (c) 2017 yohhoy
|
|
*
|
|
* Permission is hereby granted, free of charge, to any person obtaining a copy
|
|
* of this software and associated documentation files (the "Software"), to deal
|
|
* in the Software without restriction, including without limitation the rights
|
|
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
|
|
* copies of the Software, and to permit persons to whom the Software is
|
|
* furnished to do so, subject to the following conditions:
|
|
*
|
|
* The above copyright notice and this permission notice shall be included in all
|
|
* copies or substantial portions of the Software.
|
|
*
|
|
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
|
|
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
|
|
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
|
|
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
|
|
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
|
|
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
|
|
* SOFTWARE.
|
|
*/
|
|
#ifndef YAMC_TTAS_SPIN_MUTEX_HPP_
|
|
#define YAMC_TTAS_SPIN_MUTEX_HPP_
|
|
|
|
#include <atomic>
|
|
#include "yamc_backoff_spin.hpp"
|
|
|
|
|
|
namespace yamc {
|
|
|
|
/*
|
|
* Test-and-Test-And-Swap(TTAS) spinlock implementation
|
|
*
|
|
* - yamc::spin_ttas::mutex
|
|
* - yamc::spin_ttas::basic_mutex<BackoffPolicy>
|
|
*/
|
|
namespace spin_ttas {
|
|
|
|
template <typename BackoffPolicy>
|
|
class basic_mutex {
|
|
std::atomic<int> state_{0};
|
|
|
|
public:
|
|
basic_mutex() = default;
|
|
~basic_mutex() = default;
|
|
|
|
basic_mutex(const basic_mutex&) = delete;
|
|
basic_mutex& operator=(const basic_mutex&) = delete;
|
|
|
|
void lock()
|
|
{
|
|
typename BackoffPolicy::state state;
|
|
int expected;
|
|
do {
|
|
while (state_.load(std::memory_order_relaxed) != 0) {
|
|
BackoffPolicy::wait(state);
|
|
}
|
|
expected = 0;
|
|
} while (!state_.compare_exchange_weak(expected, 1, std::memory_order_acquire));
|
|
}
|
|
|
|
bool try_lock()
|
|
{
|
|
int expected = 0;
|
|
return state_.compare_exchange_weak(expected, 1, std::memory_order_acquire);
|
|
}
|
|
|
|
void unlock()
|
|
{
|
|
state_.store(0, std::memory_order_release);
|
|
}
|
|
};
|
|
|
|
using mutex = basic_mutex<YAMC_BACKOFF_SPIN_DEFAULT>;
|
|
|
|
} // namespace spin_ttas
|
|
} // namespace yamc
|
|
|
|
#endif
|