libcarla/include/system/boost/sort/common/spinlock.hpp
2024-10-18 13:19:59 +08:00

89 lines
3.0 KiB
C++

//----------------------------------------------------------------------------
/// @file spinlock_t.hpp
/// @brief
///
/// @author Copyright (c) 2010 2015 Francisco José Tapia (fjtapia@gmail.com )\n
/// Distributed under the Boost Software License, Version 1.0.\n
/// ( See accompanyingfile LICENSE_1_0.txt or copy at
/// http://www.boost.org/LICENSE_1_0.txt )
/// @version 0.1
///
/// @remarks
//-----------------------------------------------------------------------------
#ifndef __BOOST_SORT_PARALLEL_DETAIL_UTIL_SPINLOCK_HPP
#define __BOOST_SORT_PARALLEL_DETAIL_UTIL_SPINLOCK_HPP
#include <atomic>
#include <ctime>
#include <functional>
#include <memory>
#include <mutex>
#include <thread>
namespace boost
{
namespace sort
{
namespace common
{
//
//---------------------------------------------------------------------------
/// @class spinlock_t
/// @brief This class implement, from atomic variables, a spinlock
/// @remarks This class meet the BasicLockable requirements ( lock, unlock )
//---------------------------------------------------------------------------
class spinlock_t
{
private:
//------------------------------------------------------------------------
// P R I V A T E V A R I A B L E S
//------------------------------------------------------------------------
std::atomic_flag af;
public:
//
//-------------------------------------------------------------------------
// function : spinlock_t
/// @brief class constructor
/// @param [in]
//-------------------------------------------------------------------------
explicit spinlock_t ( ) noexcept { af.clear ( ); };
//
//-------------------------------------------------------------------------
// function : lock
/// @brief Lock the spinlock_t
//-------------------------------------------------------------------------
void lock ( ) noexcept
{
while (af.test_and_set (std::memory_order_acquire))
{
std::this_thread::yield ( );
};
};
//
//-------------------------------------------------------------------------
// function : try_lock
/// @brief Try to lock the spinlock_t, if not, return false
/// @return true : locked
/// false: not previous locked
//-------------------------------------------------------------------------
bool try_lock ( ) noexcept
{
return not af.test_and_set (std::memory_order_acquire);
};
//
//-------------------------------------------------------------------------
// function : unlock
/// @brief unlock the spinlock_t
//-------------------------------------------------------------------------
void unlock ( ) noexcept { af.clear (std::memory_order_release); };
}; // E N D C L A S S S P I N L O C K
//
//***************************************************************************
}; // end namespace common
}; // end namespace sort
}; // end namespace boost
//***************************************************************************
#endif