historical/toontown-classic.git/panda/include/mutexSpinlockImpl.h
2024-01-16 11:20:27 -06:00

54 lines
1.3 KiB
C++

/**
* PANDA 3D SOFTWARE
* Copyright (c) Carnegie Mellon University. All rights reserved.
*
* All use of this software is subject to the terms of the revised BSD
* license. You should have received a copy of this license along
* with this source code in a file named "LICENSE."
*
* @file mutexSpinlockImpl.h
* @author drose
* @date 2006-04-11
*/
#ifndef MUTEXSPINLOCKIMPL_H
#define MUTEXSPINLOCKIMPL_H
#include "dtoolbase.h"
#include "selectThreadImpl.h"
#ifdef MUTEX_SPINLOCK
#ifdef PHAVE_ATOMIC
#include <atomic>
#endif
/**
* Uses a simple user-space spinlock to implement a mutex. It is usually not
* a good idea to use this implementation, unless you are building Panda for a
* specific application on a specific SMP machine, and you are confident that
* you have at least as many CPU's as you have threads.
*/
class EXPCL_DTOOL_DTOOLBASE MutexSpinlockImpl {
public:
constexpr MutexSpinlockImpl() noexcept = default;
MutexSpinlockImpl(const MutexSpinlockImpl &copy) = delete;
MutexSpinlockImpl &operator = (const MutexSpinlockImpl &copy) = delete;
public:
INLINE void lock();
INLINE bool try_lock();
INLINE void unlock();
private:
void do_lock();
std::atomic_flag _flag = ATOMIC_FLAG_INIT;
};
#include "mutexSpinlockImpl.I"
#endif // MUTEX_SPINLOCK
#endif