Long live Qt!

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]