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Diffstat (limited to 'doc/src/snippets/code/doc_src_unix-signal-handlers.qdoc')
-rw-r--r-- | doc/src/snippets/code/doc_src_unix-signal-handlers.qdoc | 110 |
1 files changed, 110 insertions, 0 deletions
diff --git a/doc/src/snippets/code/doc_src_unix-signal-handlers.qdoc b/doc/src/snippets/code/doc_src_unix-signal-handlers.qdoc new file mode 100644 index 0000000..8abcba6 --- /dev/null +++ b/doc/src/snippets/code/doc_src_unix-signal-handlers.qdoc @@ -0,0 +1,110 @@ +//! [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] |