What should be the mode and channel while restarting unit files

In go-systemd, what should be the second and third parameters for restarting the units.

// RestartUnit restarts a service.  If a service is restarted that isn't
// running it will be started.
func (c *Conn) RestartUnit(name string, mode string, ch chan<- string)    (int, error) {
return c.startJob(ch, "org.freedesktop.systemd1.Manager.RestartUnit", name, mode)
}

Solution

From PR 203, you can see that method used/tested as:

// Restart the unit
reschan = make(chan string)
_, err = conn.RestartUnit(target, "replace", reschan)
if err != nil {
    t.Fatal(err)
}

job = <-reschan
if job != "done" {
    t.Fatal("Job is not done:", job)
}

So you have to create your own label and channel.

From dbus/methods.go

// Takes the unit to activate, plus a **mode string**.

The mode needs to be one of:

replace (the call will start the unit and its dependencies, possibly replacing already queued jobs that conflict with this),

fail (the call will start the unit and its dependencies, but will fail if this would change an already queued job),

isolate (the call will start the unit in question and terminate all units that aren't dependencies of it),

ignore-dependencies (it will start a unit but ignore all its dependencies),

ignore-requirements (it will start a unit but only ignore the requirement dependencies).

It is not recommended to make use of the latter two options.