qfuturewatcher.cpp

Go to the documentation of this file.

/****************************************************************************
**
** Copyright (C) 2014 Digia Plc and/or its subsidiary(-ies).
** Contact: http://www.qt-project.org/legal
**
** This file is part of the QtCore module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and Digia.  For licensing terms and
** conditions see http://qt.digia.com/licensing.  For further information
** use the contact form at http://qt.digia.com/contact-us.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 2.1 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL included in the
** packaging of this file.  Please review the following information to
** ensure the GNU Lesser General Public License version 2.1 requirements
** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** In addition, as a special exception, Digia gives you certain additional
** rights.  These rights are described in the Digia Qt LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3.0 as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL included in the
** packaging of this file.  Please review the following information to
** ensure the GNU General Public License version 3.0 requirements will be
** met: http://www.gnu.org/copyleft/gpl.html.
**
**
** $QT_END_LICENSE$
**
****************************************************************************/

#include "qfuturewatcher.h"

#ifndef QT_NO_QFUTURE

#include <QtCore/qcoreevent.h>
#include <QtCore/qcoreapplication.h>
#include <QtCore/qthread.h>

#include "qfuturewatcher_p.h"

QT_BEGIN_NAMESPACE

QFutureWatcherBase::QFutureWatcherBase(QObject *parent)
    :QObject(*new QFutureWatcherBasePrivate, parent)
{ }

void QFutureWatcherBase::cancel()
{
    futureInterface().cancel();
}

void QFutureWatcherBase::setPaused(bool paused)
{
    futureInterface().setPaused(paused);
}

void QFutureWatcherBase::pause()
{
    futureInterface().setPaused(true);
}

void QFutureWatcherBase::resume()
{
    futureInterface().setPaused(false);
}

void QFutureWatcherBase::togglePaused()
{
    futureInterface().togglePaused();
}

int QFutureWatcherBase::progressValue() const
{
    return futureInterface().progressValue();
}

int QFutureWatcherBase::progressMinimum() const
{
    return futureInterface().progressMinimum();
}

int QFutureWatcherBase::progressMaximum() const
{
    return futureInterface().progressMaximum();
}

QString QFutureWatcherBase::progressText() const
{
    return futureInterface().progressText();
}

bool QFutureWatcherBase::isStarted() const
{
    return futureInterface().queryState(QFutureInterfaceBase::Started);
}

bool QFutureWatcherBase::isFinished() const
{
    Q_D(const QFutureWatcherBase);
    return d->finished;
}

bool QFutureWatcherBase::isRunning() const
{
    return futureInterface().queryState(QFutureInterfaceBase::Running);
}

bool QFutureWatcherBase::isCanceled() const
{
    return futureInterface().queryState(QFutureInterfaceBase::Canceled);
}

bool QFutureWatcherBase::isPaused() const
{
    return futureInterface().queryState(QFutureInterfaceBase::Paused);
}

void QFutureWatcherBase::waitForFinished()
{
    futureInterface().waitForFinished();
}

bool QFutureWatcherBase::event(QEvent *event)
{
    Q_D(QFutureWatcherBase);
    if (event->type() == QEvent::FutureCallOut) {
        QFutureCallOutEvent *callOutEvent = static_cast<QFutureCallOutEvent *>(event);

        if (futureInterface().isPaused()) {
            d->pendingCallOutEvents.append(callOutEvent->clone());
            return true;
        }

        if (callOutEvent->callOutType == QFutureCallOutEvent::Resumed
            && !d->pendingCallOutEvents.isEmpty()) {
            // send the resume
            d->sendCallOutEvent(callOutEvent);

            // next send all pending call outs
            for (int i = 0; i < d->pendingCallOutEvents.count(); ++i)
                d->sendCallOutEvent(d->pendingCallOutEvents.at(i));
            qDeleteAll(d->pendingCallOutEvents);
            d->pendingCallOutEvents.clear();
        } else {
            d->sendCallOutEvent(callOutEvent);
        }
        return true;
    }
    return QObject::event(event);
}

void QFutureWatcherBase::setPendingResultsLimit(int limit)
{
    Q_D(QFutureWatcherBase);
    d->maximumPendingResultsReady = limit;
}

void QFutureWatcherBase::connectNotify(const char * signal)
{
    Q_D(QFutureWatcherBase);
    if (qstrcmp(signal, SIGNAL(resultReadyAt(int))) == 0)
        d->resultAtConnected.ref();
#ifndef QT_NO_DEBUG
    if (qstrcmp(signal, SIGNAL(finished())) == 0) {
        if (futureInterface().isRunning()) {
            //connections should be established before calling stFuture to avoid race.
            // (The future could finish before the connection is made.)
            qWarning("QFutureWatcher::connect: connecting after calling setFuture() is likely to produce race");
        }
    }
#endif
}

void QFutureWatcherBase::disconnectNotify(const char * signal)
{
    Q_D(QFutureWatcherBase);
    if (qstrcmp(signal, SIGNAL(resultReadyAt(int))) == 0)
        d->resultAtConnected.deref();
}

QFutureWatcherBasePrivate::QFutureWatcherBasePrivate()
    : maximumPendingResultsReady(QThread::idealThreadCount() * 2),
      resultAtConnected(0)
{ }

void QFutureWatcherBase::connectOutputInterface()
{
    futureInterface().d->connectOutputInterface(d_func());
}

void QFutureWatcherBase::disconnectOutputInterface(bool pendingAssignment)
{
    if (pendingAssignment) {
        Q_D(QFutureWatcherBase);
        d->pendingResultsReady = 0;
        qDeleteAll(d->pendingCallOutEvents);
        d->pendingCallOutEvents.clear();
        d->finished = false;
    }

    futureInterface().d->disconnectOutputInterface(d_func());
}

void QFutureWatcherBasePrivate::postCallOutEvent(const QFutureCallOutEvent &callOutEvent)
{
    Q_Q(QFutureWatcherBase);

    if (callOutEvent.callOutType == QFutureCallOutEvent::ResultsReady) {
        if (pendingResultsReady.fetchAndAddRelaxed(1) >= maximumPendingResultsReady)
            q->futureInterface().d->internal_setThrottled(true);
    }

    QCoreApplication::postEvent(q, callOutEvent.clone());
}

void QFutureWatcherBasePrivate::callOutInterfaceDisconnected()
{
    QCoreApplication::removePostedEvents(q_func(), QEvent::FutureCallOut);
}

void QFutureWatcherBasePrivate::sendCallOutEvent(QFutureCallOutEvent *event)
{
    Q_Q(QFutureWatcherBase);

    switch (event->callOutType) {
        case QFutureCallOutEvent::Started:
            emit q->started();
        break;
        case QFutureCallOutEvent::Finished:
            finished = true;
            emit q->finished();
        break;
        case QFutureCallOutEvent::Canceled:
            pendingResultsReady = 0;
            emit q->canceled();
        break;
        case QFutureCallOutEvent::Paused:
            if (q->futureInterface().isCanceled())
                break;
            emit q->paused();
        break;
        case QFutureCallOutEvent::Resumed:
            if (q->futureInterface().isCanceled())
                break;
            emit q->resumed();
        break;
        case QFutureCallOutEvent::ResultsReady: {
            if (q->futureInterface().isCanceled())
                break;

            if (pendingResultsReady.fetchAndAddRelaxed(-1) <= maximumPendingResultsReady)
                q->futureInterface().setThrottled(false);

            const int beginIndex = event->index1;
            const int endIndex = event->index2;

            emit q->resultsReadyAt(beginIndex, endIndex);

            if (int(resultAtConnected) <= 0)
                break;

            for (int i = beginIndex; i < endIndex; ++i)
                emit q->resultReadyAt(i);

        } break;
        case QFutureCallOutEvent::Progress:
            if (q->futureInterface().isCanceled())
                break;

            emit q->progressValueChanged(event->index1);
            if (!event->text.isNull()) // ###
                q->progressTextChanged(event->text);
        break;
        case QFutureCallOutEvent::ProgressRange:
            emit q->progressRangeChanged(event->index1, event->index2);
        break;
        default: break;
    }
}


QT_END_NAMESPACE

#else

// On Symbian winscw target QT_NO_QFUTURE and QT_NO_CONCURRENT are both defined.
// However moc will be run without having them set, so provide a dummy stub at
// least for the slots to prevent linker errors.

void QFutureWatcherBase::cancel() { }
void QFutureWatcherBase::setPaused(bool) { }
void QFutureWatcherBase::pause() { }
void QFutureWatcherBase::resume() { }
void QFutureWatcherBase::togglePaused() { }
bool QFutureWatcherBase::event(QEvent *) { return false; }
void QFutureWatcherBase::connectNotify(const char *) { }
void QFutureWatcherBase::disconnectNotify(const char *) { }

#endif // QT_NO_QFUTURE