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/****************************************************************************
**
** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
** Contact: http://www.qt-project.org/legal
**
** This file is part of the documentation of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:BSD$
** You may use this file under the terms of the BSD license as follows:
**
** "Redistribution and use in source and binary forms, with or without
** modification, are permitted provided that the following conditions are
** met:
** * Redistributions of source code must retain the above copyright
** notice, this list of conditions and the following disclaimer.
** * Redistributions in binary form must reproduce the above copyright
** notice, this list of conditions and the following disclaimer in
** the documentation and/or other materials provided with the
** distribution.
** * Neither the name of Digia Plc and its Subsidiary(-ies) nor the names
** of its contributors may be used to endorse or promote products derived
** from this software without specific prior written permission.
**
**
** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
**
** $QT_END_LICENSE$
**
****************************************************************************/
//! [0]
class MyDaemon : public QObject
{
Q_OBJECT
public:
MyDaemon(QObject *parent = 0);
~MyDaemon();
// Unix signal handlers.
static void hupSignalHandler(int unused);
static void termSignalHandler(int unused);
public slots:
// Qt signal handlers.
void handleSigHup();
void handleSigTerm();
private:
static int sighupFd[2];
static int sigtermFd[2];
QSocketNotifier *snHup;
QSocketNotifier *snTerm;
};
//! [0]
//! [1]
MyDaemon::MyDaemon(QObject *parent)
: QObject(parent)
{
if (::socketpair(AF_UNIX, SOCK_STREAM, 0, sighupFd))
qFatal("Couldn't create HUP socketpair");
if (::socketpair(AF_UNIX, SOCK_STREAM, 0, sigtermFd))
qFatal("Couldn't create TERM socketpair");
snHup = new QSocketNotifier(sighupFd[1], QSocketNotifier::Read, this);
connect(snHup, SIGNAL(activated(int)), this, SLOT(handleSigHup()));
snTerm = new QSocketNotifier(sigtermFd[1], QSocketNotifier::Read, this);
connect(snTerm, SIGNAL(activated(int)), this, SLOT(handleSigTerm()));
...
}
//! [1]
//! [2]
static int setup_unix_signal_handlers()
{
struct sigaction hup, term;
hup.sa_handler = MyDaemon::hupSignalHandler;
sigemptyset(&hup.sa_mask);
hup.sa_flags = 0;
hup.sa_flags |= SA_RESTART;
if (sigaction(SIGHUP, &hup, 0) > 0)
return 1;
term.sa_handler = MyDaemon::termSignalHandler;
sigemptyset(&term.sa_mask);
term.sa_flags |= SA_RESTART;
if (sigaction(SIGTERM, &term, 0) > 0)
return 2;
return 0;
}
//! [2]
//! [3]
void MyDaemon::hupSignalHandler(int)
{
char a = 1;
::write(sighupFd[0], &a, sizeof(a));
}
void MyDaemon::termSignalHandler(int)
{
char a = 1;
::write(sigtermFd[0], &a, sizeof(a));
}
//! [3]
//! [4]
void MyDaemon::handleSigTerm()
{
snTerm->setEnabled(false);
char tmp;
::read(sigtermFd[1], &tmp, sizeof(tmp));
// do Qt stuff
snTerm->setEnabled(true);
}
void MyDaemon::handleSigHup()
{
snHup->setEnabled(false);
char tmp;
::read(sighupFd[1], &tmp, sizeof(tmp));
// do Qt stuff
snHup->setEnabled(true);
}
//! [4]
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