source: XMLIO_V2/external/src/POCO/Foundation/PriorityNotificationQueue.cpp @ 80

//
// PriorityNotificationQueue.cpp
//
// $Id: //poco/1.3/Foundation/src/PriorityNotificationQueue.cpp#2 $
//
// Library: Foundation
// Package: Notifications
// Module:  PriorityNotificationQueue
//
// Copyright (c) 2009, Applied Informatics Software Engineering GmbH.
// and Contributors.
//
// Permission is hereby granted, free of charge, to any person or organization
// obtaining a copy of the software and accompanying documentation covered by
// this license (the "Software") to use, reproduce, display, distribute,
// execute, and transmit the Software, and to prepare derivative works of the
// Software, and to permit third-parties to whom the Software is furnished to
// do so, all subject to the following:
// 
// The copyright notices in the Software and this entire statement, including
// the above license grant, this restriction and the following disclaimer,
// must be included in all copies of the Software, in whole or in part, and
// all derivative works of the Software, unless such copies or derivative
// works are solely in the form of machine-executable object code generated by
// a source language processor.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
// SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
// FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
// ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
// DEALINGS IN THE SOFTWARE.
//


#include <Poco/PriorityNotificationQueue.h>
#include <Poco/NotificationCenter.h>
#include <Poco/Notification.h>
#include <Poco/SingletonHolder.h>


namespace Poco {


PriorityNotificationQueue::PriorityNotificationQueue()
{
}


PriorityNotificationQueue::~PriorityNotificationQueue()
{
        clear();
}


void PriorityNotificationQueue::enqueueNotification(Notification::Ptr pNotification, int priority)
{
        poco_check_ptr (pNotification);
        FastMutex::ScopedLock lock(_mutex);
        if (_waitQueue.empty())
        {
                _nfQueue.insert(NfQueue::value_type(priority, pNotification));
        }
        else
        {
                poco_assert_dbg(_nfQueue.empty());
                WaitInfo* pWI = _waitQueue.front();
                _waitQueue.pop_front();
                pWI->pNf = pNotification;
                pWI->nfAvailable.set();
        }       
}


Notification* PriorityNotificationQueue::dequeueNotification()
{
        FastMutex::ScopedLock lock(_mutex);
        return dequeueOne().duplicate();
}


Notification* PriorityNotificationQueue::waitDequeueNotification()
{
        Notification::Ptr pNf;
        WaitInfo* pWI = 0;
        {
                FastMutex::ScopedLock lock(_mutex);
                pNf = dequeueOne();
                if (pNf) return pNf.duplicate();
                pWI = new WaitInfo;
                _waitQueue.push_back(pWI);
        }
        pWI->nfAvailable.wait();
        pNf = pWI->pNf;
        delete pWI;
        return pNf.duplicate();
}


Notification* PriorityNotificationQueue::waitDequeueNotification(long milliseconds)
{
        Notification::Ptr pNf;
        WaitInfo* pWI = 0;
        {
                FastMutex::ScopedLock lock(_mutex);
                pNf = dequeueOne();
                if (pNf) return pNf.duplicate();
                pWI = new WaitInfo;
                _waitQueue.push_back(pWI);
        }
        if (pWI->nfAvailable.tryWait(milliseconds))
        {
                pNf = pWI->pNf;
        }
        else
        {
                FastMutex::ScopedLock lock(_mutex);
                pNf = pWI->pNf;
                for (WaitQueue::iterator it = _waitQueue.begin(); it != _waitQueue.end(); ++it)
                {
                        if (*it == pWI)
                        {
                                _waitQueue.erase(it);
                                break;
                        }
                }
        }
        delete pWI;
        return pNf.duplicate();
}


void PriorityNotificationQueue::dispatch(NotificationCenter& notificationCenter)
{
        FastMutex::ScopedLock lock(_mutex);
        Notification::Ptr pNf = dequeueOne();
        while (pNf)
        {
                notificationCenter.postNotification(pNf);
                pNf = dequeueOne();
        }
}


void PriorityNotificationQueue::wakeUpAll()
{
        FastMutex::ScopedLock lock(_mutex);
        for (WaitQueue::iterator it = _waitQueue.begin(); it != _waitQueue.end(); ++it)
        {
                (*it)->nfAvailable.set();
        }
        _waitQueue.clear();
}


bool PriorityNotificationQueue::empty() const
{
        FastMutex::ScopedLock lock(_mutex);
        return _nfQueue.empty();
}

        
int PriorityNotificationQueue::size() const
{
        FastMutex::ScopedLock lock(_mutex);
        return static_cast<int>(_nfQueue.size());
}


void PriorityNotificationQueue::clear()
{
        FastMutex::ScopedLock lock(_mutex);
        _nfQueue.clear();       
}


bool PriorityNotificationQueue::hasIdleThreads() const
{
        FastMutex::ScopedLock lock(_mutex);
        return !_waitQueue.empty();
}


Notification::Ptr PriorityNotificationQueue::dequeueOne()
{
        Notification::Ptr pNf;
        NfQueue::iterator it = _nfQueue.begin();
        if (it != _nfQueue.end())
        {
                pNf = it->second;
                _nfQueue.erase(it);
        }
        return pNf;
}


PriorityNotificationQueue& PriorityNotificationQueue::defaultQueue()
{
        static SingletonHolder<PriorityNotificationQueue> sh;
        return *sh.get();
}


} // namespace Poco