[sensord] Use systemd notify instead of forking a daemon. Fixes JB#36189

Using systemd specific startup notification is preferable over cusrom
daemon forks.

Add support for systemd-notify and use it instead of forking.
Signed-off-by: Simo Piiroinen <simo.piiroinen@jollamobile.com>

rpm/sensorfw-qt5.spec

@@ -20,6 +20,7 @@ BuildRequires:  pkgconfig(Qt5DBus)
 BuildRequires:  pkgconfig(Qt5Network)
 BuildRequires:  pkgconfig(Qt5Test)
 BuildRequires:  pkgconfig(mlite5)
+BuildRequires:  pkgconfig(libsystemd)
 BuildRequires:  doxygen
 BuildRequires:  systemd
 BuildRequires:  libudev-devel

rpm/sensorfwd.service

@@ -5,8 +5,8 @@ Requires=dbus.service
 Conflicts=actdead.target
 
 [Service]
-Type=forking
-ExecStart=/usr/sbin/sensorfwd -c=/etc/sensorfw/primaryuse.conf -d --log-level=warning --no-magnetometer-bg-calibration
+Type=notify
+ExecStart=/usr/sbin/sensorfwd -c=/etc/sensorfw/primaryuse.conf --systemd --log-level=warning --no-magnetometer-bg-calibration
 ExecReload=/bin/kill -HUP $MAINPID
 Restart=always
 RestartSec=1

sensord/main.cpp

@@ -33,6 +33,8 @@
 #include <QtCore/QCoreApplication>
 #include <QtCore/QDebug>
 
+#include <systemd/sd-daemon.h>
+
 #include <signal.h>
 #include <iostream>
 #include <errno.h>
@@ -175,6 +177,11 @@ int main(int argc, char *argv[])
         exit(EXIT_FAILURE);
     }
 
+    if (parser.notifySystemd())
+    {
+        sd_notify(0, "READY=1");
+    }
+
     int ret = app.exec();
     sensordLogD() << "Exiting...";
     Config::close();
@@ -185,6 +192,7 @@ void printUsage()
 {
     qDebug() << "Usage: sensord [OPTIONS]";
     qDebug() << " -d, --daemon                     Detach from terminal and run as daemon.\n";
+    qDebug() << " -s, --systemd                    Notify systemd when ready.\n";
     qDebug() << " -l=N, --log-level=<level>        Use given logging level. Messages are logged for";
     qDebug() << "                                  the given and higher priority levels. Level";
     qDebug() << "                                  can also be notched up by sending SIGUSR1 to";

sensord/parser.cpp

@@ -33,6 +33,7 @@ Parser::Parser(QStringList arguments) :
     configFile_(false),
     configDir_(false),
     daemon_(false),
+    systemd_(false),
     magnetometerCalibration_(true),
     configFilePath_(""),
     logLevel_(QtWarningMsg)
@@ -81,7 +82,9 @@ void Parser::parsingCommandLine(QStringList arguments)
         else if (opt.startsWith("--no-magnetometer-bg-calibration"))
             magnetometerCalibration_ = false;
         else if (opt.startsWith("-d") || opt.startsWith("--daemon"))
-            daemon_ = true;
+            daemon_ = true, systemd_ = false;
+        else if (opt.startsWith("-s") || opt.startsWith("--systemd"))
+            systemd_ = true, daemon_ = false;
         else if (opt.startsWith("-h") || opt.startsWith("--help"))
             printHelp_ = true;
         else if (opt.startsWith("-"))
@@ -134,3 +137,8 @@ bool Parser::createDaemon() const
     return daemon_;
 }
 
+bool Parser::notifySystemd() const
+{
+    return systemd_;
+}
+

sensord/parser.h

@@ -48,6 +48,7 @@ public:
     bool contextInfo() const;
     bool magnetometerCalibration() const;
     bool createDaemon() const;
+    bool notifySystemd() const;
 
 private:
     void parsingCommandLine(QStringList arguments);
@@ -57,6 +58,7 @@ private:
     bool configFile_;
     bool configDir_;
     bool daemon_;
+    bool systemd_;
     bool magnetometerCalibration_;
 
     QString configFilePath_;

sensord/sensord.pro

@@ -8,6 +8,8 @@ TARGET = sensorfwd
 CONFIG += console \
           link_pkgconfig
 
+PKGCONFIG += libsystemd
+
 SENSORFW_INCLUDEPATHS = .. \
                         ../include \
                         ../filters \