/**************************************************************************** ** ** Copyright (C) 2011 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. ** ** $QT_BEGIN_LICENSE:BSD$ ** 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 Nokia Corporation 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, 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]