diff options
Diffstat (limited to 'src/corelib/kernel/qwineventnotifier.cpp')
| -rw-r--r-- | src/corelib/kernel/qwineventnotifier.cpp | 114 |
1 files changed, 46 insertions, 68 deletions
diff --git a/src/corelib/kernel/qwineventnotifier.cpp b/src/corelib/kernel/qwineventnotifier.cpp index f9e91e73d7..afbf4227dc 100644 --- a/src/corelib/kernel/qwineventnotifier.cpp +++ b/src/corelib/kernel/qwineventnotifier.cpp @@ -1,46 +1,11 @@ -/**************************************************************************** -** -** Copyright (C) 2016 The Qt Company Ltd. -** Contact: https://www.qt.io/licensing/ -** -** 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 The Qt Company. For licensing terms -** and conditions see https://www.qt.io/terms-conditions. For further -** information use the contact form at https://www.qt.io/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 3 as published by the Free Software -** Foundation and appearing in the file LICENSE.LGPL3 included in the -** packaging of this file. Please review the following information to -** ensure the GNU Lesser General Public License version 3 requirements -** will be met: https://www.gnu.org/licenses/lgpl-3.0.html. -** -** GNU General Public License Usage -** Alternatively, this file may be used under the terms of the GNU -** General Public License version 2.0 or (at your option) the GNU General -** Public license version 3 or any later version approved by the KDE Free -** Qt Foundation. The licenses are as published by the Free Software -** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3 -** included in the packaging of this file. Please review the following -** information to ensure the GNU General Public License requirements will -** be met: https://www.gnu.org/licenses/gpl-2.0.html and -** https://www.gnu.org/licenses/gpl-3.0.html. -** -** $QT_END_LICENSE$ -** -****************************************************************************/ +// Copyright (C) 2016 The Qt Company Ltd. +// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only #include "qwineventnotifier_p.h" #include "qcoreapplication.h" #include "qthread.h" +#include <QPointer> QT_BEGIN_NAMESPACE @@ -117,10 +82,7 @@ QWinEventNotifier::QWinEventNotifier(QObject *parent) QWinEventNotifier::QWinEventNotifier(HANDLE hEvent, QObject *parent) : QObject(*new QWinEventNotifierPrivate(hEvent, false), parent) { - Q_D(QWinEventNotifier); - - d->registerWaitObject(); - d->enabled = true; + setEnabled(true); } /*! @@ -198,9 +160,20 @@ void QWinEventNotifier::setEnabled(bool enable) // event shall be ignored. d->winEventActPosted.testAndSetRelaxed(QWinEventNotifierPrivate::Posted, QWinEventNotifierPrivate::IgnorePosted); - d->registerWaitObject(); - } else if (d->waitHandle != NULL) { - d->unregisterWaitObject(); + // The notifier can't be registered, if 'enabled' flag was false. + // The code in the else branch ensures that. + Q_ASSERT(!d->registered); + SetThreadpoolWait(d->waitObject, d->handleToEvent, NULL); + d->registered = true; + } else if (d->registered) { + // Stop waiting for an event. However, there may be a callback queued + // already after the call. + SetThreadpoolWait(d->waitObject, NULL, NULL); + // So, to avoid a race condition after a possible call to + // setEnabled(true), wait for a possibly outstanding callback + // to complete. + WaitForThreadpoolWaitCallbacks(d->waitObject, TRUE); + d->registered = false; } } @@ -226,12 +199,17 @@ bool QWinEventNotifier::event(QEvent * e) // again. if (d->winEventActPosted.fetchAndStoreRelaxed(QWinEventNotifierPrivate::NotPosted) == QWinEventNotifierPrivate::Posted && d->enabled) { - d->unregisterWaitObject(); + // Clear the flag, as the wait object is implicitly unregistered + // when the callback is queued. + d->registered = false; + QPointer<QWinEventNotifier> alive(this); emit activated(d->handleToEvent, QPrivateSignal()); - if (d->enabled && d->waitHandle == NULL) - d->registerWaitObject(); + if (alive && d->enabled && !d->registered) { + SetThreadpoolWait(d->waitObject, d->handleToEvent, NULL); + d->registered = true; + } } return true; default: @@ -240,8 +218,25 @@ bool QWinEventNotifier::event(QEvent * e) return QObject::event(e); } -void CALLBACK QWinEventNotifierPrivate::wfsoCallback(void *context, BOOLEAN /*ignore*/) +QWinEventNotifierPrivate::QWinEventNotifierPrivate(HANDLE h, bool e) + : handleToEvent(h), enabled(e), registered(false) +{ + waitObject = CreateThreadpoolWait(waitCallback, this, NULL); + if (waitObject == NULL) + qErrnoWarning("QWinEventNotifier:: CreateThreadpollWait failed."); +} + +QWinEventNotifierPrivate::~QWinEventNotifierPrivate() +{ + CloseThreadpoolWait(waitObject); +} + +void QWinEventNotifierPrivate::waitCallback(PTP_CALLBACK_INSTANCE instance, PVOID context, + PTP_WAIT wait, TP_WAIT_RESULT waitResult) { + Q_UNUSED(instance); + Q_UNUSED(wait); + Q_UNUSED(waitResult); QWinEventNotifierPrivate *nd = reinterpret_cast<QWinEventNotifierPrivate *>(context); // Do not post an event, if an event is already in the message queue. Note @@ -252,23 +247,6 @@ void CALLBACK QWinEventNotifierPrivate::wfsoCallback(void *context, BOOLEAN /*ig } } -bool QWinEventNotifierPrivate::registerWaitObject() -{ - if (RegisterWaitForSingleObject(&waitHandle, handleToEvent, wfsoCallback, this, - INFINITE, WT_EXECUTEONLYONCE) == 0) { - qErrnoWarning("QWinEventNotifier: RegisterWaitForSingleObject failed."); - return false; - } - return true; -} - -void QWinEventNotifierPrivate::unregisterWaitObject() -{ - // Unregister the wait handle and wait for pending callbacks to finish. - if (UnregisterWaitEx(waitHandle, INVALID_HANDLE_VALUE)) - waitHandle = NULL; - else - qErrnoWarning("QWinEventNotifier: UnregisterWaitEx failed."); -} - QT_END_NAMESPACE + +#include "moc_qwineventnotifier.cpp" |