1426509 - In desktop-instrumentation runs in automation, keep a count of every time a XBL binding is attached to an element and save the data as an artifact

Status: RESOLVED WONTFIX

(Core :: DOM: Core & HTML, task, P2)

Description

[Brian Grinstead [:bgrins]]

The desktop-instrumentation taskcluster job (added in Bug 1376546) runs the entire b-c suite in one chunk on Nightly builds. This is useful for getting information about what elements get created in the browser UI.

Right now we use JS only to capture this information which is intentionally focused only on the browser.xul document and also attempts to 'de-dupe' certain elements that get created in each test (i.e. the main browser chrome). See https://dxr.mozilla.org/mozilla-central/rev/1624b88874765bf57e9feba176d30149c748d9d2/testing/mochitest/browser-test.js#122-127.

But an alternate and more comprehensive view of this data would be to instrument the platform at least in the parent proess, i.e. nsXBLBinding::SetBoundElement. This would get instances in all documents and also let us track things like which bindings get created before the first paint.

Here's a push that does a printf with the binding id and includes boilerplate needed to get the inst job to run on try: https://hg.mozilla.org/try/rev/4f40f02c359fd12b5fa7e977261701c28f2ed5a8. Ideally we could turn this into something that could be landed and tracked over time though. Here's the basic idea:

* Check if the TEST_SUITE env variable is equal to "browser-chrome-instrumentation"
* Keep a map of binding ids and the number of times they get created
* At browser shutdown serialize that map and write it out to an artifact file at the path specified in the MOZ_UPLOAD_DIR environment variable

Comment 1

[Dave Townsend [:mossop]]

Attachment: Bug 1426509: Instrument the number of XBL binding attachments.

Review commit: https://reviewboard.mozilla.org/r/225926/diff/#index_header
See other reviews: https://reviewboard.mozilla.org/r/225926/

Comment 2

[Dave Townsend [:mossop]]

Attachment: Bug 1426509: Enable browser-instrumentation tests for try.

Review commit: https://reviewboard.mozilla.org/r/225928/diff/#index_header
See other reviews: https://reviewboard.mozilla.org/r/225928/

Comment 3

[Dave Townsend [:mossop]]

As discussed this morning the try results we have for this are enough for now, no need to land this at the moment.