1565162 - [meta] Use JSWindowActor API instead of framescripts for the partial CDP implementation

Status: RESOLVED WONTFIX

(Remote Protocol :: Agent, task, P3)

Description

[Alexandre Poirot [:ochameau]]

For now, /remote/ codebase uses the to-be-deprecated message manager API. (if that's not already deprecated?)
This is being done between TabSession and ContentProcessSession.
A replacement API has been implemented and is already usable: JSWindowActor.
https://searchfox.org/mozilla-central/source/dom/chrome-webidl/JSWindowActor.webidl

We should switch to this API in order to:

• prevent /remote/ be the last codebase to still use message manager API (in case there is an intent to remove it completly)
• ease supporting fission (remoted web page iframes) and tab process switches

Personnaly, that would help me understand this API in order to apply the same work against the DevTools codebase.

Comment 1

[Alexandre Poirot [:ochameau]]

Attachment: Bug 1565162 - Use JSWindowActor APIs for the remote agent.

Comment 2

[Chris Peterson [:cpeterson]]

Tentatively moving all bugs whose summaries mention "Fission" (or other Fission-related keywords) but are not assigned to a Fission Milestone to the "?" triage milestone.

This will generate a lot of bugmail, so you can filter your bugmail for the following UUID and delete them en masse:

0ee3c76a-bc79-4eb2-8d12-05dc0b68e732

Comment 3

[Neha Kochar [:neha]]

Alex, is the patch still being worked on? I'm moving this to a later milestone but let me know if this is expected to be complete sooner.

Comment 4

[Alexandre Poirot [:ochameau]]

I am not. I moved back to DevTools. I don't know if anyone is planning to work on that.

Comment 5

[Andreas Tolfsen ❲:ato❳]

I spoke briefly with AutomatedTester about the remote agent’s lack
of Fission compatibility earlier this week. We have some lose
intention of addressing some of these concerns early/mid next
quarter, and that will in all likelihood be based on the approach
ochameau has outlined in the WIP patch.

Comment 6

[Henrik Skupin [:whimboo][⌚️UTC+1]]

So I'm considering to pick-up this bug right now, even with the fact in mind that we originally wanted to do it next year. But after speaking with Alexandre it's clear that the amount of work, which would be necessary to do next year, is much larger due to all the rewrites of additional code added until then.

Reason is that the work for eg. bug 1599413 and bug 1599773 is way easier to do with the JSWindowActor approach. Also other methods and events could benefit from it.

As such I've tested Alexandre's patch and with some modifications I got it already working. The page navigation tests even with Fission enabled are passing, which is a good sign given that those are the most problematic ones in terms of process switches. There is only a leak remaining maybe because of the use of Map. Nevertheless I will upload a recent version, to be safe that it's not getting lost.

Next is to clean-up all the work starting from the child processes, the parent process, and all the domains...

Comment 7

[Henrik Skupin [:whimboo][⌚️UTC+1]]

As informed I should not get started with that yet. So I will leave the patch as is, and will pick it up again in Q1 2020. Sorry for the noise.

Note that I will add dependencies to all the features, which I think would need a rewrite with this patch being landed.

Comment 8

[Chris Peterson [:cpeterson]]

Tracking for Fission Nightly (M6)

Comment 9

[Henrik Skupin [:whimboo][⌚️UTC+1]]

This is more likely a meta bug given that several steps will be necessary to get this done.

Comment 10

[Chris Peterson [:cpeterson]]

Tracking for Fission M6b Nightly milestone.

Comment 11

[Chris Peterson [:cpeterson]]

Moving Remote Protocol bugs to Fission Beta milestone (M7).

Comment 12

[Neha Kochar [:neha]]

Henrik, what are the next steps here and who can work on this for M7 (Fx88)? Thanks!

Comment 13

[Chris Peterson [:cpeterson]]

DevTools meta bugs don't need to block Fission MVP. However, we will continue to monitor these meta bugs for any new bugs blocking them as potential blockers for Fission MVP.

Comment 14

[Henrik Skupin [:whimboo][⌚️UTC+1]]

Most likely we are not going to add Fission support for our CDP implementation, but will keep focus on Fission for the WebDriver BiDi implementation. As such this might become a wontfix.

Comment 15

[Henrik Skupin [:whimboo][⌚️UTC+1]]

With the work on bug 1601245 done some weeks ago there might not be a need to switch to the actor framework. But lets keep it open for now.

Comment 16

[Henrik Skupin [:whimboo][⌚️UTC+1]]

We are not going to finish this work on this bug. Instead one should use the WebDriver BiDi protocol.