mutex.cuh

Go to the documentation of this file.

/******************************************************************************
 * Copyright (c) 2011, Duane Merrill.  All rights reserved.
 * Copyright (c) 2011-2018, NVIDIA CORPORATION.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 *     * Neither the name of the NVIDIA CORPORATION nor the
 *       names of its contributors may be used to endorse or promote products
 *       derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL NVIDIA CORPORATION BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 ******************************************************************************/
 
#pragma once
 
#if (__cplusplus > 199711L) || (defined(_MSC_VER) && _MSC_VER >= 1800)
    #include <mutex>
#else
    #if defined(_WIN32) || defined(_WIN64)
        #include <intrin.h>
 
        #define WIN32_LEAN_AND_MEAN
        #define NOMINMAX
        #include <windows.h>
        #undef WIN32_LEAN_AND_MEAN
        #undef NOMINMAX
 
        #pragma intrinsic(_ReadWriteBarrier)
 
    #endif
#endif
 
#include "../util_namespace.cuh"
 
 
CUB_NS_PREFIX
 
namespace cub {
 
 
struct Mutex
{
#if (__cplusplus > 199711L) || (defined(_MSC_VER) && _MSC_VER >= 1800)
 
    std::mutex mtx;
 
    void Lock()
    {
        mtx.lock();
    }
 
    void Unlock()
    {
        mtx.unlock();
    }
 
    void TryLock()
    {
        mtx.try_lock();
    }
 
#else       //__cplusplus > 199711L
 
    #if defined(_MSC_VER)
 
        // Microsoft VC++
        typedef long Spinlock;
 
    #else
 
        // GNU g++
        typedef int Spinlock;
 
        __forceinline__ void _ReadWriteBarrier()
        {
            __sync_synchronize();
        }
 
        __forceinline__ long _InterlockedExchange(volatile int * const Target, const int Value)
        {
            // NOTE: __sync_lock_test_and_set would be an acquire barrier, so we force a full barrier
            _ReadWriteBarrier();
            return __sync_lock_test_and_set(Target, Value);
        }
 
        __forceinline__ void YieldProcessor()
        {
        }
 
    #endif  // defined(_MSC_VER)
 
        volatile Spinlock lock;
 
        Mutex() : lock(0) {}
 
        __forceinline__ void Lock()
        {
            while (1)
            {
                if (!_InterlockedExchange(&lock, 1)) return;
                while (lock) YieldProcessor();
            }
        }
 
 
        __forceinline__ void Unlock()
        {
            _ReadWriteBarrier();
            lock = 0;
        }
 
#endif      // __cplusplus > 199711L
 
};
 
 
 
 
}               // CUB namespace
CUB_NS_POSTFIX  // Optional outer namespace(s)