diff options
Diffstat (limited to 'src/corelib/kernel/qwineventnotifier.cpp')
| -rw-r--r-- | src/corelib/kernel/qwineventnotifier.cpp | 161 |
1 files changed, 71 insertions, 90 deletions
diff --git a/src/corelib/kernel/qwineventnotifier.cpp b/src/corelib/kernel/qwineventnotifier.cpp index 8cf6b018d4..afbf4227dc 100644 --- a/src/corelib/kernel/qwineventnotifier.cpp +++ b/src/corelib/kernel/qwineventnotifier.cpp @@ -1,48 +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 "qeventdispatcher_win_p.h" #include "qcoreapplication.h" - -#include <private/qthread_p.h> +#include "qthread.h" +#include <QPointer> QT_BEGIN_NAMESPACE @@ -119,14 +82,7 @@ QWinEventNotifier::QWinEventNotifier(QObject *parent) QWinEventNotifier::QWinEventNotifier(HANDLE hEvent, QObject *parent) : QObject(*new QWinEventNotifierPrivate(hEvent, false), parent) { - Q_D(QWinEventNotifier); - QAbstractEventDispatcher *eventDispatcher = d->threadData.loadRelaxed()->eventDispatcher.loadRelaxed(); - if (Q_UNLIKELY(!eventDispatcher)) { - qWarning("QWinEventNotifier: Can only be used with threads started with QThread"); - return; - } - eventDispatcher->registerEventNotifier(this); - d->enabled = true; + setEnabled(true); } /*! @@ -193,19 +149,31 @@ void QWinEventNotifier::setEnabled(bool enable) return; d->enabled = enable; - QAbstractEventDispatcher *eventDispatcher = d->threadData.loadRelaxed()->eventDispatcher.loadRelaxed(); - if (!eventDispatcher) // perhaps application is shutting down - return; if (Q_UNLIKELY(thread() != QThread::currentThread())) { qWarning("QWinEventNotifier: Event notifiers cannot be enabled or disabled from another thread"); return; } if (enable) { - d->signaledCount = 0; - eventDispatcher->registerEventNotifier(this); - } else { - eventDispatcher->unregisterEventNotifier(this); + // It is possible that the notifier was disabled after an event was already + // posted. In that case we set a state that indicates that such an obsolete + // event shall be ignored. + d->winEventActPosted.testAndSetRelaxed(QWinEventNotifierPrivate::Posted, + QWinEventNotifierPrivate::IgnorePosted); + // 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; } } @@ -216,56 +184,69 @@ void QWinEventNotifier::setEnabled(bool enable) bool QWinEventNotifier::event(QEvent * e) { Q_D(QWinEventNotifier); - if (e->type() == QEvent::ThreadChange) { + + switch (e->type()) { + case QEvent::ThreadChange: if (d->enabled) { QMetaObject::invokeMethod(this, "setEnabled", Qt::QueuedConnection, Q_ARG(bool, true)); setEnabled(false); } - } - QObject::event(e); // will activate filters - if (e->type() == QEvent::WinEventAct) { - emit activated(d->handleToEvent, QPrivateSignal()); + break; + case QEvent::WinEventAct: + // Emit notification, but only if the event has not been invalidated + // since by the notifier being disabled, even if it was re-enabled + // again. + if (d->winEventActPosted.fetchAndStoreRelaxed(QWinEventNotifierPrivate::NotPosted) + == QWinEventNotifierPrivate::Posted && d->enabled) { + // 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 (alive && d->enabled && !d->registered) { + SetThreadpoolWait(d->waitObject, d->handleToEvent, NULL); + d->registered = true; + } + } return true; + default: + break; } - return false; + return QObject::event(e); } -static void CALLBACK wfsoCallback(void *context, BOOLEAN /*ignore*/) +QWinEventNotifierPrivate::QWinEventNotifierPrivate(HANDLE h, bool e) + : handleToEvent(h), enabled(e), registered(false) { - QWinEventNotifierPrivate *nd = reinterpret_cast<QWinEventNotifierPrivate *>(context); - QAbstractEventDispatcher *eventDispatcher = nd->threadData.loadRelaxed()->eventDispatcher.loadRelaxed(); - - // Happens when Q(Core)Application is destroyed before QWinEventNotifier. - // https://bugreports.qt.io/browse/QTBUG-70214 - if (!eventDispatcher) { // perhaps application is shutting down - qWarning("QWinEventNotifier: no event dispatcher, application shutting down? Cannot deliver event."); - return; - } - - QEventDispatcherWin32Private *edp = QEventDispatcherWin32Private::get( - static_cast<QEventDispatcherWin32 *>(eventDispatcher)); - ++nd->signaledCount; - edp->postActivateEventNotifiers(); + waitObject = CreateThreadpoolWait(waitCallback, this, NULL); + if (waitObject == NULL) + qErrnoWarning("QWinEventNotifier:: CreateThreadpollWait failed."); } -bool QWinEventNotifierPrivate::registerWaitObject() +QWinEventNotifierPrivate::~QWinEventNotifierPrivate() { - if (RegisterWaitForSingleObject(&waitHandle, handleToEvent, wfsoCallback, this, - INFINITE, WT_EXECUTEONLYONCE) == 0) { - qErrnoWarning("QWinEventNotifier: RegisterWaitForSingleObject failed."); - return false; - } - return true; + CloseThreadpoolWait(waitObject); } -void QWinEventNotifierPrivate::unregisterWaitObject() +void QWinEventNotifierPrivate::waitCallback(PTP_CALLBACK_INSTANCE instance, PVOID context, + PTP_WAIT wait, TP_WAIT_RESULT waitResult) { - // Unregister the wait handle and wait for pending callbacks to finish. - if (UnregisterWaitEx(waitHandle, INVALID_HANDLE_VALUE)) - waitHandle = NULL; - else - qErrnoWarning("QWinEventNotifier: UnregisterWaitEx failed."); + 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 + // that an event that was previously invalidated will be reactivated. + if (nd->winEventActPosted.fetchAndStoreRelaxed(QWinEventNotifierPrivate::Posted) + == QWinEventNotifierPrivate::NotPosted) { + QCoreApplication::postEvent(nd->q_func(), new QEvent(QEvent::WinEventAct)); + } } QT_END_NAMESPACE + +#include "moc_qwineventnotifier.cpp" |