1742872 - browser_ProcessPriorityManager.js should check that the iframe of test_iframe_navigate is in a different process than the top level page

Status: RESOLVED FIXED

(Core :: DOM: Content Processes, task, P3)

Description

[Andrew McCreight [:mccr8]]

As seen in bug 1742785 comment 5, browser_ProcessPriorityManager.js should have some checks when Fission is enabled that the iframe in test_iframe_navigate is in a different process than the top level page. The failure to do this will manifest in weird ways due to dom.ipc.processCount.webIsolated being greater than 1.

Comment 1

[Andrew McCreight [:mccr8]]

For thoroughness, we should also check that the process of the initial iframe in the second tab is different than the process of the first tab.

I'll rewrite the checks to more explicitly check for these failures.

Note that existing parts of the test will fail if either of these new checks fail, so it isn't like we might have missed failures, but I think doing explicit process uniqueness checks makes it easier to understand some failure conditions.

Comment 2

[Andrew McCreight [:mccr8]]

Attachment: Bug 1742872, part 1 - Add more process uniqueness checks to browser_ProcessPriorityManager.js.

Also, add a comment about how you can run the priority manager tests on
non-Windows platforms, and rename some variables for clarity.

Comment 3

[Andrew McCreight [:mccr8]]

I'll wait for bug 1742785 to reland and stick before landing this, as there will be some trivial rebasing involved.

Comment 4

[Andrew McCreight [:mccr8]]

Attachment: Bug 1742872, part 2 - Fix the initial iframe shutdown race in the priority manager test.

With Fission, the process containing the initial page in the iframe
for the iframe navigation test might start shutting down after we
navigate away from it, because nothing else is loaded into it. If
this happens, the process will become FOREGROUND priority, causing
a test failure. See bug 1727340.

To work around this, I open an additional tab that is same-site with
the initial iframe, which should ensure that the process doesn't go
away too soon.

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/e2137baded64
part 1 - Add more process uniqueness checks to browser_ProcessPriorityManager.js. r=nika
https://hg.mozilla.org/integration/autoland/rev/316ba8d6681c
part 2 - Fix the initial iframe shutdown race in the priority manager test. r=nika

Comment 6

[Alexandru Michis [:malexandru]]

https://hg.mozilla.org/mozilla-central/rev/e2137baded64
https://hg.mozilla.org/mozilla-central/rev/316ba8d6681c