periodic: Add TriggerRun method.

[lukedirtwalker]

This allows to run a task immediately after periodic creation,
or at any point in time when it is deemed necessary.

---

This change is 

[scrye]

Reviewed 2 of 2 files at r1.
Reviewable status: all files reviewed, 2 unresolved discussions (waiting on @lukedirtwalker and @oncilla)

---

go/lib/periodic/periodic.go, line 63 at r1 (raw file):

	cancelF  context.CancelFunc
	trigger  chan struct{}
	stoppedB bool

What does stoppedB stand for?

I assumed it is the boolean equivalent to chan stopped, but in Stop and Kill the two can get out of sync.

---

go/lib/periodic/periodic.go, line 120 at r1 (raw file):

	r.mtx.Lock()
	defer r.mtx.Unlock()
	if !r.stoppedB {

Wouldn't draining r.stop give you the same info here?

select {
case <-r.stop:
default:
    r.trigger <- struct{}{}
}

[lukedirtwalker]

Reviewable status: 1 of 2 files reviewed, 2 unresolved discussions (waiting on @oncilla and @scrye)

---

go/lib/periodic/periodic.go, line 63 at r1 (raw file):

Previously, scrye (Sergiu Costea) wrote…

What does stoppedB stand for?

I assumed it is the boolean equivalent to chan stopped, but in Stop and Kill the two can get out of sync.

Done.

---

go/lib/periodic/periodic.go, line 120 at r1 (raw file):

Previously, scrye (Sergiu Costea) wrote…

Wouldn't draining r.stop give you the same info here?

select {
case <-r.stop:
default:
    r.trigger <- struct{}{}
}

I think just having select either case should be fine.

[scrye]

Reviewable status: 1 of 2 files reviewed, 1 unresolved discussion (waiting on @lukedirtwalker, @oncilla, and @scrye)

---

go/lib/periodic/periodic.go, line 120 at r1 (raw file):

Previously, lukedirtwalker (Lukas Vogel) wrote…

I think just having select either case should be fine.

I think you are right. It looks good to me.

---

go/lib/periodic/periodic.go, line 107 at r2 (raw file):

// the next execution will be in 3 minutes.
//
// If the task is currently running this function will block until the trigger was received.

Please add a comment clarifying that the function can return without a triggered run happening. Appending or the runner received a stop signal should be enough.

[scrye]

Reviewed 1 of 1 files at r2.
Reviewable status: all files reviewed, 1 unresolved discussion (waiting on @lukedirtwalker and @oncilla)

[oncilla]

Reviewable status: all files reviewed, 1 unresolved discussion (waiting on @lukedirtwalker and @oncilla)

[lukedirtwalker]

Reviewable status: all files reviewed, 1 unresolved discussion (waiting on @oncilla and @scrye)

---

go/lib/periodic/periodic.go, line 107 at r2 (raw file):

Previously, scrye (Sergiu Costea) wrote…

Please add a comment clarifying that the function can return without a triggered run happening. Appending or the runner received a stop signal should be enough.

Done.

[scrye]

Reviewed 1 of 1 files at r3.
Reviewable status: complete! all files reviewed, all discussions resolved

[scrye]

Reviewed 1 of 1 files at r4.
Reviewable status: complete! all files reviewed, all discussions resolved

[scrye]

Reviewable status: complete! all files reviewed, all discussions resolved