From: APTX <marek321@gmail.com>
Date: Sun, 29 Jan 2017 14:27:06 +0000 (+0100)
Subject: Properly handle UNIX signals.
X-Git-Url: https://gitweb.aptx.org/?a=commitdiff_plain;h=a4d0ce950521d60df3dd340ee003801aedf7232f;p=localmylist.git

Properly handle UNIX signals.

Very few operations can actualy be done in a signal handler.
This change follows Qt's recommendation on calling Qt functions
from UNIX signal handlers:

http://doc.qt.io/qt-5/unix-signals.html
---

diff --git a/.gitignore b/.gitignore
index 1e8cc43..4d5d29b 100644
--- a/.gitignore
+++ b/.gitignore
@@ -26,11 +26,17 @@ Makefile*
 moc_*.cpp
 ui_*.h
 qrc_*.cpp
+*.qmake.stash
 
 # qtcreator generated files
 *.pro.user
 *.pro.user.*
 *.autosave
+*.files
+*.creator
+*.creator.*
+*.config
+*.includes
 
 # xemacs temporary files
 *.flc
diff --git a/anioni/anioni.cpp b/anioni/anioni.cpp
old mode 100644
new mode 100755
index 48f345f..164e684
--- a/anioni/anioni.cpp
+++ b/anioni/anioni.cpp
@@ -13,6 +13,14 @@
 #include <QTimer>
 #include <QDebug>
 
+#ifdef Q_OS_UNIX
+#	include <QSocketNotifier>
+#	include <signal.h>
+#	include <unistd.h>
+#	include <sys/types.h>
+#	include <sys/socket.h>
+#endif
+
 AniOni::AniOni(int argc, char **argv) :
 	QObject(), QtService<QCoreApplication>(argc, argv, "LocalMyList Daemon")
 {
@@ -20,7 +28,11 @@ AniOni::AniOni(int argc, char **argv) :
 	runUdpClient = false;
 	runRenameHandler = false;
 	watchDirectories = false;
-	requestFailTimer = 0;
+	requestFailTimer = nullptr;
+#ifdef Q_OS_UNIX
+	setupUnixSignalHandler();
+	signalFdNotifier = nullptr;
+#endif
 }
 
 void AniOni::handleUdpClientError()
@@ -78,6 +90,11 @@ void AniOni::failRequests()
 
 void AniOni::start()
 {
+#ifdef Q_OS_UNIX
+	signalFdNotifier = new QSocketNotifier(signalFd[1], QSocketNotifier::Read, this);
+	connect(signalFdNotifier, SIGNAL(activated(int)), this, SLOT(handleUnixSignal()));
+#endif
+
 #if defined(Q_OS_WIN)
 	QSettings s(QDir::currentPath() + "/anioni.ini", QSettings::IniFormat);
 #elif defined(Q_OS_UNIX)
@@ -150,6 +167,21 @@ void AniOni::start()
 	requestFailTimer->start();
 }
 
+#ifdef Q_OS_UNIX
+void AniOni::handleUnixSignal()
+{
+	signalFdNotifier->setEnabled(false);
+	char tmp;
+	auto ignored = ::read(signalFd[1], &tmp, sizeof(tmp));
+	(void)ignored;
+
+	int signal = static_cast<int>(tmp);
+	qInfo("Got signal %d, quitting...", signal);
+	QTimer::singleShot(0, qApp, SLOT(quit()));
+	signalFdNotifier->setEnabled(true);
+}
+#endif
+
 void AniOni::loadSettings(QSettings &s)
 {
 	LocalMyList::instance()->loadLocalSettings(s);
@@ -166,3 +198,34 @@ void AniOni::log(const QString &message, QtServiceBase::MessageType type)
 	logMessage(message, type);
 	qWarning() << message;
 }
+
+#ifdef Q_OS_UNIX
+void AniOni::setupUnixSignalHandler()
+{
+	if (::socketpair(AF_UNIX, SOCK_STREAM, 0, signalFd))
+		qFatal("Couldn't create signal socketpair");
+
+	struct sigaction action;
+	action.sa_handler = &AniOni::unixSignalHandler;
+	sigemptyset(&action.sa_mask);
+	action.sa_flags = 0;
+	action.sa_flags |= SA_RESTART;
+
+	if (sigaction(SIGTERM, &action, NULL) < 0)
+		qFatal("Failed to set SIGTERM handler");
+	if (sigaction(SIGINT, &action, NULL) < 0)
+		qFatal("Failed to set SIGINT handler");
+	if (sigaction(SIGHUP, &action, NULL) < 0)
+		qFatal("Failed to set SIGHUP handler");
+}
+
+void AniOni::unixSignalHandler(int signal)
+{
+	qWarning("handling signal %d", signal);
+	char c = static_cast<char>(signal);
+	auto ignored = ::write(signalFd[0], &c, sizeof(c));
+	(void)ignored;
+}
+
+int AniOni::signalFd[2] = {};
+#endif
diff --git a/anioni/anioni.h b/anioni/anioni.h
old mode 100644
new mode 100755
index d618209..f641d9e
--- a/anioni/anioni.h
+++ b/anioni/anioni.h
@@ -5,6 +5,9 @@
 #include <QSettings>
 
 class QTimer;
+#ifdef Q_OS_UNIX
+class QSocketNotifier;
+#endif
 
 class AniOni : public QObject, public QtService<QCoreApplication>
 {
@@ -12,10 +15,6 @@ class AniOni : public QObject, public QtService<QCoreApplication>
 public:
 	explicit AniOni(int argc, char **argv);
 
-signals:
-	
-public slots:
-
 protected slots:
 	void handleUdpClientError();
 	void failRequests();
@@ -23,10 +22,22 @@ protected slots:
 protected:
 	void start();
 
+private slots:
+#ifdef Q_OS_UNIX
+	void handleUnixSignal();
+#endif
+
 private:
 	void loadSettings(QSettings &s);
 	void log(const QString &message, QtServiceBase::MessageType type);
 
+#ifdef Q_OS_UNIX
+	static void setupUnixSignalHandler();
+	static void unixSignalHandler(int signal);
+	static int signalFd[2];
+	QSocketNotifier *signalFdNotifier;
+#endif
+
 	bool runUdpClient;
 	bool runRenameHandler;
 	bool watchDirectories;
diff --git a/anioni/main.cpp b/anioni/main.cpp
old mode 100644
new mode 100755
index 55bbac0..2508a1a
--- a/anioni/main.cpp
+++ b/anioni/main.cpp
@@ -1,32 +1,7 @@
 #include "anioni.h"
 
-#ifdef Q_OS_UNIX
-#	include <signal.h>
-
-void sighandler(int)
-{
-	qDebug("Caught signal. Exiting...");
-	qApp->quit();
-}
-#endif
-
 int main(int argc, char *argv[])
 {
 	AniOni a(argc, argv);
-
-#ifdef Q_OS_UNIX
-	struct sigaction action;
-	action.sa_handler = sighandler;
-	sigemptyset(&action.sa_mask);
-	action.sa_flags = 0;
-
-	if (sigaction(SIGTERM, &action, NULL) < 0)
-		qWarning("Failed to set signal handler");
-	if (sigaction(SIGINT, &action, NULL) < 0)
-		qWarning("Failed to set signal handler");
-	if (sigaction(SIGHUP, &action, NULL) < 0)
-		qWarning("Failed to set signal handler");
-#endif
-
 	return a.exec();
 }