diff -r dee5afe5301f -r 3f74d0d4af4c doc/src/snippets/code/doc_src_unix-signal-handlers.qdoc --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/doc/src/snippets/code/doc_src_unix-signal-handlers.qdoc Thu Apr 08 14:19:33 2010 +0300 @@ -0,0 +1,151 @@ +/**************************************************************************** +** +** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies). +** All rights reserved. +** Contact: Nokia Corporation (qt-info@nokia.com) +** +** This file is part of the documentation of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:LGPL$ +** No Commercial Usage +** This file contains pre-release code and may not be distributed. +** You may use this file in accordance with the terms and conditions +** contained in the Technology Preview License Agreement accompanying +** this package. +** +** 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, Nokia gives you certain additional +** rights. These rights are described in the Nokia Qt LGPL Exception +** version 1.1, included in the file LGPL_EXCEPTION.txt in this package. +** +** If you have questions regarding the use of this file, please contact +** Nokia at qt-info@nokia.com. +** +** +** +** +** +** +** +** +** $QT_END_LICENSE$ +** +****************************************************************************/ + +//! [0] +class MyDaemon : public QObject +{ + Q_OBJECT + + public: + MyDaemon(QObject *parent = 0, const char *name = 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, const char *name) + : QObject(parent,name) +{ + 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]