Standard Backend

Service Backend

Is a dummy that simply runs as a normal console process
Uses QCoreApplication as application
Logging is done formatted to stderr
Ensures only 1 instance is running by using a lockfile
Maps common unix signals to commands:
- SIGINT, SIGTERM, SIGQUIT: stop
- SIGHUB: reload
- SIGTSTP: pause
- SIGCONT: resume
- SIGUSR1: callback "SIGUSR1"
- SIGUSR2: callback "SIGUSR2"
Can handle windows signals to stop the service: CTRL_C_EVENT, CTRL_BREAK_EVENT
Stopping is only possible via those signals or from within the service itself
Callbacks signatures:
- void SIGUSR1(): Invoked by handling the unix signal SIGUSR1
- void SIGUSR2(): Invoked by handling the unix signal SIGUSR2

Support Flags:
- QtService::ServiceControl::SupportsStart (only on platforms that provice QProcess)
- QtService::ServiceControl::SupportsStop
- QtService::ServiceControl::SupportsStatus
Custom commands:
- qint64 getPid(): Returns the PID auf the currently running instance, or -1 if none is running
Starting is done by simply running the service executable as detached process
The lockfile is used to determine the service state - which means only services that use the backend can be controlled properly
Stopping is done by sending a signal to the service

All QDebug is logged into journald
Uses QCoreApplication as application
Can be used for user and system services
should be used with -platform minimal to avoid any dependencies to the windowing system
supported systemd commands:
- start
- stop
- reload
Implemented as notify-daemon - automatically reports the status to systemd
Supports the systemd watchdog (optionally)
Supports named and default socket activation (via a .socket file)
Maps common unix signals to commands:
- SIGINT, SIGTERM, SIGQUIT: stop
- SIGHUB: reload
- SIGTSTP: pause
- SIGCONT: resume
- SIGUSR1: callback "SIGUSR1"
- SIGUSR2: callback "SIGUSR2"
Callbacks signatures:
- void SIGUSR1(): Invoked by handling the unix signal SIGUSR1
- void SIGUSR2(): Invoked by handling the unix signal SIGUSR2

Support Flags:
Custom commands:
- Any command that is a valid systemctl command. The general signature is: int command(parameters...) and will invoke systemctl as systemctl [--user|--system] [--no-block] <command> <service-name> <arguments> and return the result of that command. The first two parameters as well as the service name are automatically determined by the backend, depending on the control configuration. For example, to send the SIGUSR1 signal to a running service, you would call callCommand<int>("kill", QStringLiteral("--signal=SIGUSR1"));

Logging: The service registers as eventsource and reports event to the windows event log
Uses QCoreApplication as application
supported windows commands:
- start
- stop
- pause
- resume
- custom commands (callback "command")
Windows service type: SERVICE_WIN32_OWN_PROCESS
Windows service flags: SERVICE_ACCEPT_PAUSE_CONTINUE | SERVICE_ACCEPT_STOP | SERVICE_ACCEPT_SHUTDOWN
Periodically reports startup state
Callbacks signatures:
- void command(DWORD): Invoke by handling custom service commands (code range is [128;255])

All QDebug is logged with syslog
Uses QCoreApplication as application
Supports named socket activation (via the plist files Sockets category)
Maps common unix signals to commands:
- SIGINT, SIGTERM, SIGQUIT: stop
- SIGHUB: reload
- SIGTSTP: pause
- SIGCONT: resume
- SIGUSR1: callback "SIGUSR1"
- SIGUSR2: callback "SIGUSR2"
Callbacks signatures:
- void SIGUSR1(): Invoked by handling the unix signal SIGUSR1
- void SIGUSR2(): Invoked by handling the unix signal SIGUSR2

Support Flags:
Custom commands:
- Any command that is a valid launchctl command. The general signature is: int command(parameters...) and will invoke launchctl as launchctl <command> <arguments> <service-name> and return the result of that command. The service name is automatically determined by the backend, depending on the control configuration.

Logging is done to logcat, as usual for Qt for android
Uses QAndroidService as application
Handles Android service commands:
- "service is started" (either via binding or explicit start): start
- stopService (or stopSelf): stop
- onStartCommand: callback "onStartCommand"
- onBind: callback "onBind"
Callbacks signatures:
- int onStartCommand(QAndroidIntent, int, int): Run in the android thread (!) to react to the corresponding command
- QAndroidBinder *onBind(QAndroidIntent): Run in the android thread (!) to react to the corresponding command

Support Flags:
Custom commands:
- void startWithIntent(QAndroidIntent): Starts the service with a custom intent. If the service is already running it is delivered to the running service. The target class is set automatically, so you don't have to set it on your intent.
- bool bind(QAndroidServiceConnection*, QtAndroid::BindFlags): Binds to the given service. If it is not already running that will also start the service. The bind status is reported to the QAndroidServiceConnection.
- void unbind(QAndroidServiceConnection*): Unbinds the service connected by the given connection. If no other binders are connected and the service was not started explicitly, this will stop the service.