1470023 - Lazily load PluginContent.jsm

Status: RESOLVED FIXED

(Core Graveyard :: Plug-ins, enhancement)

Description

[Andrew McCreight [:mccr8]]

content.js contains this code:

// TODO: Load this lazily so the JSM is run only if a relevant event/message fires.
void new PluginContent(global);

I haven't looked at the code, but hopefully we can avoid loading this JSM if there are no plugins in the content process. According to my analyzer, this is like 30kb of memory (almost entirely scripts).

Comment 1

[Kris Maglione [:kmag]]

I think this should be pretty doable. I looked into this when I was doing bug 1464552, and initially backed away because of the pageshow and pagehide hooks. It looks like we only actually need to care about those once the module has been loaded, though, so we may be able to do this without too much trouble.

Comment 2

[Kris Maglione [:kmag]]

Attachment: Bug 1470023: Lazily load PluginContent.jsm when it's first required.

Review commit: https://reviewboard.mozilla.org/r/252642/diff/#index_header
See other reviews: https://reviewboard.mozilla.org/r/252642/

Comment 3

[Mike Conley (:mconley) (:⚙️)]

Pro-actively assigning this to kmag, since he's already got a patch up for it.

Comment 4

[:Felipe Gomes (needinfo for replies!)]

Comment on attachment 8987397 [details]
Bug 1470023: Lazily load PluginContent.jsm when it's first required.

https://reviewboard.mozilla.org/r/252642/#review259386

In addition to this, I'd make the PluginContentStub object a weak observer, to avoid the unload listener and the uninit function.

Probably follow-up fodder, but this decoder-doctor-notification might be even unnecessary. There's an existing meta-bug about getting rid of one-observer-per-tab observers (bug 1195386), which tracks bug 1348810 where this notification is discussed.

Comment 5

[Kris Maglione [:kmag]]

https://hg.mozilla.org/integration/mozilla-inbound/rev/064e448df638efc4a99fdf9f400d1eac2b7505ca
Bug 1470023: Lazily load PluginContent.jsm when it's first required. r=felipe

Comment 6

[Kris Maglione [:kmag]]

https://hg.mozilla.org/integration/mozilla-inbound/rev/f0f5158db88c8a9712b7e09fccaf10d004343e85
Bug 1470023: Follow-up: Fix weird test bustage. r=bustage CLOSED TREE

Comment 7

[Eliza Balazs [:ebalazs_]]

Backed out 2 changesets (bug 1470023) for frequent mochitest failures eg.: toolkit/components/extensions/test/mochitest/test_ext_contentscript_permission.html

Failure log: https://treeherder.mozilla.org/logviewer.html#?job_id=184850960&repo=mozilla-inbound

Push with failures: https://treeherder.mozilla.org/#/jobs?repo=mozilla-inbound&revision=064e448df638efc4a99fdf9f400d1eac2b7505ca&filter-resultStatus=testfailed&filter-resultStatus=busted&filter-resultStatus=exception&filter-resultStatus=retry&filter-resultStatus=usercancel&filter-resultStatus=runnable&selectedJob=184850960
https://treeherder.mozilla.org/#/jobs?repo=mozilla-inbound&revision=f0f5158db88c8a9712b7e09fccaf10d004343e85&filter-resultStatus=testfailed&filter-resultStatus=busted&filter-resultStatus=exception&filter-resultStatus=retry&filter-resultStatus=usercancel&filter-resultStatus=runnable&selectedJob=184860729

Backout: https://treeherder.mozilla.org/#/jobs?repo=mozilla-inbound&revision=748ba658c02b66030b99ce7576c85c57c95225b7&filter-resultStatus=testfailed&filter-resultStatus=busted&filter-resultStatus=exception&filter-resultStatus=retry&filter-resultStatus=usercancel&filter-resultStatus=runnable

Comment 8

[Kris Maglione [:kmag]]

Hrm. Apparently there's some code that depends on this frame script touching `content`, which doesn't happen after the lazification. I'm going to add a hack to keep touching it for now and file a follow-up to remove it.

Comment 9

[Kris Maglione [:kmag]]

https://hg.mozilla.org/integration/mozilla-inbound/rev/1adc0372343e6ca2248f3c16cede6a103aebcaa7
Bug 1470023: Lazily load PluginContent.jsm when it's first required. r=felipe

Comment 10

[Stefan Hindli [:stefan_hindli]]

Backed out 3 changesets (bug 1470023, bug 1469719, bug 1470965) for | toolkit/components/perfmonitoring/tests/browser/browser_compartments.js on a CLOSED TREE 

Problematic push: https://treeherder.mozilla.org/#/jobs?repo=mozilla-inbound&revision=bab121b4dd84f9715e6a9efa652556a91ea60a3c&filter-resultStatus=testfailed&filter-resultStatus=busted&filter-resultStatus=exception&filter-classifiedState=unclassified

Failure: https://treeherder.mozilla.org/#/jobs?repo=mozilla-inbound&filter-resultStatus=testfailed&filter-resultStatus=busted&filter-resultStatus=exception&fromchange=43040128202efc47d4249e623e6d3ffd1a5d9588&filter-classifiedState=unclassified&selectedJob=185004097

Backout: https://treeherder.mozilla.org/#/jobs?repo=mozilla-inbound&revision=24aeaadfae0df355fb2fac7ea25ea90fa9c56ddf&filter-resultStatus=testfailed&filter-resultStatus=busted&filter-resultStatus=exception&filter-classifiedState=unclassified

Log: https://treeherder.mozilla.org/logviewer.html#?job_id=185004097&repo=mozilla-inbound&lineNumber=2513

12:29:59     INFO - TEST-UNEXPECTED-FAIL | browser/components/extensions/test/browser/test-oop-extensions/browser_ext_tabs_executeScript.js | Error: Error: No matching message handler :: Async*background@moz-extension://3ee86764-b762-5340-a5bf-c15c8f281ced/%7B62a81496-888d-f242-8ef8-442b57bff1c8%7D.js:3:11
12:29:59     INFO - async*@moz-extension://3ee86764-b762-5340-a5bf-c15c8f281ced/%7B62a81496-888d-f242-8ef8-442b57bff1c8%7D.js:1:17
12:29:59     INFO -  - 
12:29:59     INFO - Stack trace:
12:29:59     INFO -     background@moz-extension://3ee86764-b762-5340-a5bf-c15c8f281ced/%7B62a81496-888d-f242-8ef8-442b57bff1c8%7D.js:187:7
12:29:59     INFO -     async*@moz-extension://3ee86764-b762-5340-a5bf-c15c8f281ced/%7B62a81496-888d-f242-8ef8-442b57bff1c8%7D.js:1:17
12:29:59     INFO -     
12:29:59     INFO - Not taking screenshot here: see the one that was previously logged
12:29:59     INFO - TEST-UNEXPECTED-FAIL | browser/components/extensions/test/browser/test-oop-extensions/browser_ext_tabs_executeScript.js | executeScript - 
12:29:59     INFO - Stack trace:
12:29:59     INFO -     background@moz-extension://3ee86764-b762-5340-a5bf-c15c8f281ced/%7B62a81496-888d-f242-8ef8-442b57bff1c8%7D.js:188:7
12:29:59     INFO -     async*@moz-extension://3ee86764-b762-5340-a5bf-c15c8f281ced/%7B62a81496-888d-f242-8ef8-442b57bff1c8%7D.js:1:17
12:29:59     INFO -     
12:29:59     INFO - TEST-PASS | browser/components/extensions/test/browser/test-oop-extensions/browser_ext_tabs_executeScript.js | test result correct - 
12:29:59     INFO - Console message: [JavaScript Error: "Promise rejected after context unloaded: Message manager disconnected
12:29:59     INFO - " {file: "moz-extension://3ee86764-b762-5340-a5bf-c15c8f281ced/script.js" line: 2}]
12:29:59     INFO - @moz-extension://3ee86764-b762-5340-a5bf-c15c8f281ced/script.js:2:9
12:29:59     INFO - 
12:29:59     INFO - Console message: Ignoring response to aborted listener for 1099511627780
12:29:59     INFO - Console message: Cannot send function call result: other side closed connection (call data: ({path:"tabs.executeScript", args:[409, {allFrames:null, code:"42", cssOrigin:null, file:null, frameId:null, matchAboutBlank:null, runAt:"document_idle"}]}))
12:29:59     INFO - TEST-PASS | browser/components/extensions/test/browser/test-oop-extensions/browser_ext_tabs_executeScript.js | Message manager count - 
12:29:59     INFO - TEST-PASS | browser/components/extensions/test/browser/test-oop-extensions/browser_ext_tabs_executeScript.js | Pending response count - 
12:29:59     INFO - Leaving test bound testExecuteScript
12:29:59     INFO - Console message: Ignoring response to aborted listener for 1668
12:29:59     INFO - Console message: Cannot send function call result: other side closed connection (call data: ({path:"tabs.executeScript", args:[410, {allFrames:null, code:"location.href", cssOrigin:null, file:null, frameId:null, matchAboutBlank:null, runAt:"document_idle"}]}))
12:29:59     INFO - GECKO(869) | MEMORY STAT | vsize 4724MB | residentFast 794MB | heapAllocated 190MB
12:29:59     INFO - TEST-OK | browser/components/extensions/test/browser/test-oop-extensions/browser_ext_tabs_executeScript.js | took 939ms
12:29:59     INFO - Not taking screenshot here: see the one that was previously logged
12:29:59     INFO - TEST-UNEXPECTED-FAIL | browser/components/extensions/test/browser/test-oop-extensions/browser_ext_tabs_executeScript.js | Found an unexpected tab at the end of test run: about:blank - 
12:29:59     INFO - Not taking screenshot here: see the one that was previously logged
12:29:59     INFO - TEST-UNEXPECTED-FAIL | browser/components/extensions/test/browser/test-oop-extensions/browser_ext_tabs_executeScript.js | Found an unexpected tab at the end of test run: http://example.com/ - 
12:29:59     INFO - Not taking screenshot here: see the one that was previously logged
12:29:59     INFO - TEST-UNEXPECTED-FAIL | browser/components/extensions/test/browser/test-oop-extensions/browser_ext_tabs_executeScript.js | Found an unexpected tab at the end of test run: http://example.net/ - 
12:29:59     INFO - checking window state

Comment 11

[:Felipe Gomes (needinfo for replies!)]

Kris, when you land it again, could you mention bug 1471327 in the comment above the `var content` hack?

Comment 12

[Kris Maglione [:kmag]]

(In reply to :Felipe Gomes (needinfo me!) from comment #11)
> Kris, when you land it again, could you mention bug 1471327 in the comment
> above the `var content` hack?

Yup, sorry. I filed the bug before I landed so I could add it to the comment, and then forgot...

Comment 13

[Kris Maglione [:kmag]]

https://hg.mozilla.org/integration/mozilla-inbound/rev/446a587a3c239233eb717cfb1a5a509614f60649
Bug 1470023: Lazily load PluginContent.jsm when it's first required. r=felipe

Comment 14

[Dorel Luca [:dluca]]

https://hg.mozilla.org/mozilla-central/rev/446a587a3c23