988096 - Lazily load PeerConnection.js

Status: NEW

(Core :: WebRTC, defect, P5)

Description

[Michael]

This shouldn't be needed at startup.

Comment 1

[Nicholas Nethercote [inactive]]

Bug 996989 is related.

Comment 2

[Eric Rahm [:erahm]]

It's not clear to me how we would lazily load this, I don't see it imported anywhere. The best I can tell is it's loaded due to a |do_GetService(IPEERCONNECTION_MANAGER_CONTRACTID)| call [1] in |nsDocument::CanSavePresentation|.

Maybe I'm missing some sort of implicit loading elsewhere?

[1] https://dxr.mozilla.org/mozilla-central/rev/91c2b9d5c1354ca79e5b174591dbb03b32b15bbf/dom/base/nsDocument.cpp#8351-8361

Comment 3

[Randell Jesup [:jesup] (needinfo me)]

CanSavePresentation is used for killing peerconnections when you navigate so they're not held alive in the cache.

It's implicitly loaded elsewhere I believe: 
dom/media/bridge/MediaModule.cpp:

namespace mozilla
{
// Factory defined in mozilla::, defines mozilla::PeerConnectionImplConstructor
NS_GENERIC_FACTORY_CONSTRUCTOR(PeerConnectionImpl)
}


$ grep -r "PeerConnection\.js" *
browser/installer/package-manifest.in:@RESPATH@/components/PeerConnection.js
dom/webidl/PeerConnectionImpl.webidl: * PeerConnection.js' interface to the C++ PeerConnectionImpl.
dom/media/PeerConnection.manifest:component {bdc2e533-b308-4708-ac8e-a8bfade6d851} PeerConnection.js
dom/media/PeerConnection.manifest:component {d1748d4c-7f6a-4dc5-add6-d55b7678537e} PeerConnection.js
dom/media/PeerConnection.manifest:component {02b9970c-433d-4cc2-923d-f7028ac66073} PeerConnection.js
dom/media/PeerConnection.manifest:component {1775081b-b62d-4954-8ffe-a067bbf508a7} PeerConnection.js
dom/media/PeerConnection.manifest:component {7293e901-2be3-4c02-b4bd-cbef6fc24f78} PeerConnection.js
dom/media/PeerConnection.manifest:component {7fe6e18b-0da3-4056-bf3b-440ef3809e06} PeerConnection.js
dom/media/PeerConnection.manifest:component {0fb47c47-a205-4583-a9fc-cbadf8c95880} PeerConnection.js
dom/media/PeerConnection.manifest:component {4fff5d46-d827-4cd4-a970-8fd53977440e} PeerConnection.js
dom/media/PeerConnection.manifest:component {d974b814-8fde-411c-8c45-b86791b81030} PeerConnection.js
dom/media/PeerConnection.manifest:component {74b2122d-65a8-4824-aa9e-3d664cb75dc2} PeerConnection.js
dom/media/tests/mochitest/test_peerConnection_bug834153.html:    title: "Queue CreateAnswer in PeerConnection.js"
dom/media/bridge/IPeerConnection.idl: * Manager interface to PeerConnection.js so it is accessible from C++.
dom/media/moz.build:    'PeerConnection.js',
mobile/android/installer/package-manifest.in:@BINPATH@/components/PeerConnection.js
obj-debug/_build_manifests/install/dist_bin:1^_components/PeerConnection.js^_/home/jesup/src/mozilla/inbound/dom/media/PeerConnection.js
obj-debug/faster/install_dist_bin:1^_components/PeerConnection.js^_/home/jesup/src/mozilla/inbound/dom/media/PeerConnection.js

Comment 4

[Eric Rahm [:erahm]]

(In reply to Randell Jesup [:jesup] from comment #3)
> CanSavePresentation is used for killing peerconnections when you navigate so
> they're not held alive in the cache.
> 
> It's implicitly loaded elsewhere I believe: 
> dom/media/bridge/MediaModule.cpp:
> 
> namespace mozilla
> {
> // Factory defined in mozilla::, defines
> mozilla::PeerConnectionImplConstructor
> NS_GENERIC_FACTORY_CONSTRUCTOR(PeerConnectionImpl)
> }
> 
> 
> $ grep -r "PeerConnection\.js" *
> browser/installer/package-manifest.in:@RESPATH@/components/PeerConnection.js
> dom/webidl/PeerConnectionImpl.webidl: * PeerConnection.js' interface to the
> C++ PeerConnectionImpl.
> dom/media/PeerConnection.manifest:component
> {bdc2e533-b308-4708-ac8e-a8bfade6d851} PeerConnection.js
> dom/media/PeerConnection.manifest:component
> {d1748d4c-7f6a-4dc5-add6-d55b7678537e} PeerConnection.js
> dom/media/PeerConnection.manifest:component
> {02b9970c-433d-4cc2-923d-f7028ac66073} PeerConnection.js
> dom/media/PeerConnection.manifest:component
> {1775081b-b62d-4954-8ffe-a067bbf508a7} PeerConnection.js
> dom/media/PeerConnection.manifest:component
> {7293e901-2be3-4c02-b4bd-cbef6fc24f78} PeerConnection.js
> dom/media/PeerConnection.manifest:component
> {7fe6e18b-0da3-4056-bf3b-440ef3809e06} PeerConnection.js
> dom/media/PeerConnection.manifest:component
> {0fb47c47-a205-4583-a9fc-cbadf8c95880} PeerConnection.js
> dom/media/PeerConnection.manifest:component
> {4fff5d46-d827-4cd4-a970-8fd53977440e} PeerConnection.js
> dom/media/PeerConnection.manifest:component
> {d974b814-8fde-411c-8c45-b86791b81030} PeerConnection.js
> dom/media/PeerConnection.manifest:component
> {74b2122d-65a8-4824-aa9e-3d664cb75dc2} PeerConnection.js
> dom/media/tests/mochitest/test_peerConnection_bug834153.html:    title:
> "Queue CreateAnswer in PeerConnection.js"
> dom/media/bridge/IPeerConnection.idl: * Manager interface to
> PeerConnection.js so it is accessible from C++.
> dom/media/moz.build:    'PeerConnection.js',
> mobile/android/installer/package-manifest.in:@BINPATH@/components/
> PeerConnection.js
> obj-debug/_build_manifests/install/dist_bin:1^_components/PeerConnection.
> js^_/home/jesup/src/mozilla/inbound/dom/media/PeerConnection.js
> obj-debug/faster/install_dist_bin:1^_components/PeerConnection.js^_/home/
> jesup/src/mozilla/inbound/dom/media/PeerConnection.js

We discussed a bit on IRC, basically comes down to PeerConnection.js being loaded into compartment because it implements webidl interfaces (not beign Cu.imported). It's not clear to me if we can lazify that.

Comment 5

[Randell Jesup [:jesup] (needinfo me)]

> We discussed a bit on IRC, basically comes down to PeerConnection.js being
> loaded into compartment because it implements webidl interfaces (not beign
> Cu.imported). It's not clear to me if we can lazify that.

Perhaps a stub impl that lazily loads the full impl?  So the webidl makes the stub loaded, but presumably that's much smaller/faster than the complete one.

Downside is more complexity when adding interfaces.

Comment 6

[Bulk Bug Changes for mreavy's org]

Mass change P4->P5 to align with new Mozilla triage process.

Comment 7

[Byron Campen [:bwc]]

Is this still a P3 in memshrink?

Comment 8

[Andrew McCreight [:mccr8]]

I think this would be more like a P2 for content process MemShrink, assuming this is loaded into the content process by default. but I don't remember seeing it being loaded on launch when I investigated that a year or so ago.

Kris is more familiar with the current state of loading these various components. Kris, is this something we still need for content process memshrink? Thanks.

Comment 9

[Kris Maglione [:kmag]]

I believe this is only loaded eagerly in the parent process. It probably matters for qf, but not for memshrink, I think.