queuing_mutex.h

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/*
    Copyright (c) 2005-2019 Intel Corporation

    Licensed under the Apache License, Version 2.0 (the "License");
    you may not use this file except in compliance with the License.
    You may obtain a copy of the License at

        http://www.apache.org/licenses/LICENSE-2.0

    Unless required by applicable law or agreed to in writing, software
    distributed under the License is distributed on an "AS IS" BASIS,
    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    See the License for the specific language governing permissions and
    limitations under the License.




*/

#ifndef __TBB_queuing_mutex_H
#define __TBB_queuing_mutex_H

#include <cstring>
#include "atomic.h"
#include "tbb_profiling.h"

namespace tbb {


class queuing_mutex : internal::mutex_copy_deprecated_and_disabled {
public:
    queuing_mutex() {
        q_tail = NULL;
#if TBB_USE_THREADING_TOOLS
        internal_construct();
#endif
    }


    class scoped_lock: internal::no_copy {
        void initialize() {
            mutex = NULL;
            going = 0;
#if TBB_USE_ASSERT
            internal::poison_pointer(next);
#endif /* TBB_USE_ASSERT */
        }

    public:

        scoped_lock() {initialize();}

        scoped_lock( queuing_mutex& m ) {
            initialize();
            acquire(m);
        }

        ~scoped_lock() {
            if( mutex ) release();
        }

        void __TBB_EXPORTED_METHOD acquire( queuing_mutex& m );

        bool __TBB_EXPORTED_METHOD try_acquire( queuing_mutex& m );

        void __TBB_EXPORTED_METHOD release();

    private:
        queuing_mutex* mutex;

        scoped_lock *next;


        uintptr_t going;
    };

    void __TBB_EXPORTED_METHOD internal_construct();

    // Mutex traits
    static const bool is_rw_mutex = false;
    static const bool is_recursive_mutex = false;
    static const bool is_fair_mutex = true;

private:
    atomic<scoped_lock*> q_tail;

};

__TBB_DEFINE_PROFILING_SET_NAME(queuing_mutex)

} // namespace tbb

#endif /* __TBB_queuing_mutex_H */