barrier.cpp

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// The DAGFrameScheduler is a Multi-Threaded lock free and wait free scheduling library.
// © Copyright 2010 - 2014 BlackTopp Studios Inc.
/* This file is part of The DAGFrameScheduler.

    The DAGFrameScheduler is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    The DAGFrameScheduler is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with The DAGFrameScheduler.  If not, see <http://www.gnu.org/licenses/>.
*/
/* The original authors have included a copy of the license specified above in the
   'doc' folder. See 'gpl.txt'
*/
/* We welcome the use of the DAGFrameScheduler to anyone, including companies who wish to
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   However there are some practical restrictions, so if your project involves
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   Joseph Toppi - toppij@gmail.com
   John Blackwood - makoenergy02@gmail.com
*/
#ifndef _barrier_cpp
#define _barrier_cpp

#include "barrier.h"

/// @file
/// @brief Contains the implementation for the @ref Mezzanine::Threading::Barrier Barrier synchronization object.

namespace Mezzanine
{
    namespace Threading
    {
        Barrier::Barrier (const Int32& SynchThreadCount) : ThreadGoal (SynchThreadCount), ThreadCurrent (0) {}

        bool Barrier::Wait()
        {
            if (AtomicAdd(&ThreadCurrent,1) == ThreadGoal)
            {
                while(0!=AtomicCompareAndSwap32(&ThreadCurrent,ThreadGoal,0));
                return true;
            }
            else
            {
                while (ThreadCurrent < ThreadGoal && ThreadCurrent != 0); // intentionally spinning

                return false;
            }
        }

        void Barrier::SetThreadSyncCount(Int32 NewCount)
            { while(ThreadGoal!=AtomicCompareAndSwap32(&ThreadGoal,ThreadGoal,NewCount)); }
    } // \Threading namespace
} // \Mezzanine namespace
#endif