source: xplcommon/src/xplcommon/win32/CondVar.cc@ 34:ad3194cb9bef

// Copyright (c) 2013 by István Váradi

// This file is part of libxplcommon, a common utility library for
// development related to X-Plane

// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:

// 1. Redistributions of source code must retain the above copyright notice, this
//    list of conditions and the following disclaimer.
// 2. 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.

// 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 THE COPYRIGHT OWNER OR CONTRIBUTORS 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.

// The views and conclusions contained in the software and documentation are those
// of the authors and should not be interpreted as representing official policies,
// either expressed or implied, of the FreeBSD Project.

//------------------------------------------------------------------------------

#include "CondVar.h"

//------------------------------------------------------------------------------

using xplcommon::win32::CondVar;

//------------------------------------------------------------------------------

bool CondVar::wait(Mutex& inMutex, int timeout)
{
    mutex.lock();
    ++numWaiters;
    size_t generation = waitGeneration;
    mutex.unlock();

    inMutex.unlock();

    bool lastWaiter = false;
    bool wokenUp = false;
    bool waitDone = false;
    while (!waitDone) {
        int result = WaitForSingleObject(event,
                                         (timeout<0) ? INFINITE : timeout);
        if (result==WAIT_OBJECT_0) {
            mutex.lock();
            waitDone = numToRelease>0 && generation!=waitGeneration;
            if (waitDone) {
                --numToRelease;
                lastWaiter = numToRelease == 0;
                wokenUp = true;
            }
            mutex.unlock();
        } else {
            waitDone = true;
        }
    }

    inMutex.lock();

    mutex.lock();
    --numWaiters;
    mutex.unlock();

    if (lastWaiter) {
        ResetEvent(event);
    }

    return wokenUp;
}

//------------------------------------------------------------------------------

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// mode: C++
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