source: vendor/synergy/current/lib/base/CSimpleEventQueueBuffer.cpp

/*
 * synergy -- mouse and keyboard sharing utility
 * Copyright (C) 2004 Chris Schoeneman
 * 
 * This package is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * found in the file COPYING that should have accompanied this file.
 * 
 * This package 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.
 */

#include "CSimpleEventQueueBuffer.h"
#include "CStopwatch.h"
#include "CArch.h"

class CEventQueueTimer { };

//
// CSimpleEventQueueBuffer
//

CSimpleEventQueueBuffer::CSimpleEventQueueBuffer()
{
        m_queueMutex     = ARCH->newMutex();
        m_queueReadyCond = ARCH->newCondVar();
        m_queueReady     = false;
}

CSimpleEventQueueBuffer::~CSimpleEventQueueBuffer()
{
        ARCH->closeCondVar(m_queueReadyCond);
        ARCH->closeMutex(m_queueMutex);
}

void
CSimpleEventQueueBuffer::waitForEvent(double timeout)
{
        CArchMutexLock lock(m_queueMutex);
        CStopwatch timer(true);
        while (!m_queueReady) {
                double timeLeft = timeout;
                if (timeLeft >= 0.0) {
                        timeLeft -= timer.getTime();
                        if (timeLeft < 0.0) {
                                return;
                        }
                }
                ARCH->waitCondVar(m_queueReadyCond, m_queueMutex, timeLeft);
        }
}

IEventQueueBuffer::Type
CSimpleEventQueueBuffer::getEvent(CEvent&, UInt32& dataID)
{
        CArchMutexLock lock(m_queueMutex);
        if (!m_queueReady) {
                return kNone;
        }
        dataID = m_queue.back();
        m_queue.pop_back();
        m_queueReady = !m_queue.empty();
        return kUser;
}

bool
CSimpleEventQueueBuffer::addEvent(UInt32 dataID)
{
        CArchMutexLock lock(m_queueMutex);
        m_queue.push_front(dataID);
        if (!m_queueReady) {
                m_queueReady = true;
                ARCH->broadcastCondVar(m_queueReadyCond);
        }
        return true;
}

bool
CSimpleEventQueueBuffer::isEmpty() const
{
        CArchMutexLock lock(m_queueMutex);
        return !m_queueReady;
}

CEventQueueTimer*
CSimpleEventQueueBuffer::newTimer(double, bool) const
{
        return new CEventQueueTimer;
}

void
CSimpleEventQueueBuffer::deleteTimer(CEventQueueTimer* timer) const
{
        delete timer;
}