1473614 - Add debugging shorthand for pausing the thread

Status: RESOLVED FIXED

(Remote Protocol :: Marionette, enhancement, P1)

Description

[Andreas Tolfsen ❲:ato❳]

Using TimedPromise it is possible to create a promise that returns
given a duration.  However, it is a somewhat large amount of
boilerplate to do so requiring you to look up the API.

Given that WebDriver provides a largely time- and synchronisation-critical
protocol it would be useful with a shorthand to pause the thread
using async/await for an arbitrary amount of time.

This shorthand must—of course—never be used in production.

Comment 1

[Andreas Tolfsen ❲:ato❳]

Attachment: Add type checks to PollPromise and TimedPromise.

This patch introduces stricted type checks for the sync module's
PollPromise and TimedPromise.  This may seem excessive, but we have
had real and severe bugs in this area before.

Comment 2

[Andreas Tolfsen ❲:ato❳]

Attachment: Add sync function Sleep for pausing async functions.

This adds a new public API to the Marionette sync module that can
"pause" async functions for an arbitrary amount of hardcoded time.
This can be useful for debugging purposes.

Comment 3

[Andreas Tolfsen ❲:ato❳]

Attachment: Fix exported symbols in sync.

The "exported" keyword is no longer needed.

Comment 4

[Andreas Tolfsen ❲:ato❳]

Attachment: Expose API docs for MessageManagerDestroyedPromise and Sleep.

Comment 5

[Andreas Tolfsen ❲:ato❳]

try: https://treeherder.mozilla.org/#/jobs?repo=try&revision=1f7e2f4ced2c8f5f66a405cee86cea73438c8000

Comment 6

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/mozilla-inbound/rev/87a0ebcd004f
Add type checks to PollPromise and TimedPromise. r=automatedtester
https://hg.mozilla.org/integration/mozilla-inbound/rev/1ee58097b141
Add sync function Sleep for pausing async functions. r=automatedtester
https://hg.mozilla.org/integration/mozilla-inbound/rev/1d28e128807c
Fix exported symbols in sync. r=automatedtester
https://hg.mozilla.org/integration/mozilla-inbound/rev/027922b5ef04
Expose API docs for MessageManagerDestroyedPromise and Sleep. r=automatedtester

Comment 7

[Narcis Beleuzu [:NarcisB]]

Backed out for xpcshell failures on test_sync.js

Backout link: https://hg.mozilla.org/integration/mozilla-inbound/rev/bcd31adc1e7a2bac67c7f9dcce38eb42d1f66c48
Push link: https://treeherder.mozilla.org/#/jobs?repo=mozilla-inbound&revision=027922b5ef0442e4ebb07043d2b57961e6195a78
Log link: https://treeherder.mozilla.org/logviewer.html#?job_id=192136034&repo=mozilla-inbound&lineNumber=1355

Comment 8

[Andreas Tolfsen ❲:ato❳]

I believe I have fixed the fallout on slower systems.  Doing a try
run to confirm:
https://treeherder.mozilla.org/#/jobs?repo=try&revision=5cf67fb67e8c960c36a3d8902388069843387098

Comment 9

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/mozilla-inbound/rev/075c87b1393a
Add type checks to PollPromise and TimedPromise. r=automatedtester
https://hg.mozilla.org/integration/mozilla-inbound/rev/c76d0cb71ad4
Add sync function Sleep for pausing async functions. r=automatedtester
https://hg.mozilla.org/integration/mozilla-inbound/rev/684c928574c6
Fix exported symbols in sync. r=automatedtester
https://hg.mozilla.org/integration/mozilla-inbound/rev/ff6be2623035
Expose API docs for MessageManagerDestroyedPromise and Sleep. r=automatedtester

Comment 10

[Cristian Brindusan [:cbrindusan]]

https://hg.mozilla.org/mozilla-central/rev/075c87b1393a
https://hg.mozilla.org/mozilla-central/rev/c76d0cb71ad4
https://hg.mozilla.org/mozilla-central/rev/684c928574c6
https://hg.mozilla.org/mozilla-central/rev/ff6be2623035