winsw/docs/self-restarting-service.md

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# Self-restarting Windows services
## Restart from the spawned process
To support self-restarting services, winsw exposes `WINSW_EXECUTABLE` environment variable into the forked process,
which refers to the full path of *WinSW.exe* that's managing the service.
To restart the service from within, execute `%WINSW_EXECUTABLE% restart!`.
Note that you are invoking `restart!` command, not `restart` command.
This hidden command is a flavor of the `restart` operation,
where winsw creates another winsw process in a separate process group,
and restarts the service from there.
This additional indirection is necessary because Windows Service Control Manager (SCM) will kill child processes recursively when it stops a service.
SCM doesn't provide the restart operation as an atomic operation either, so winsw implements restart by a sequence of stop and start.
The second winsw process in a separate process group ensures that winsw can survive this massacre to execute the start call.