Bug 202434

Summary: XMLHttpRequest sometimes prevents pages from entering the back/forward cache
Product: WebKit Reporter: Chris Dumez <cdumez>
Component: Page LoadingAssignee: Chris Dumez <cdumez>
Status: RESOLVED FIXED    
Severity: Normal CC: achristensen, beidson, commit-queue, ggaren, thorton, webkit-bug-importer, youennf
Priority: P2 Keywords: InRadar
Version: WebKit Nightly Build   
Hardware: Unspecified   
OS: Unspecified   
Bug Depends on:    
Bug Blocks: 202293    
Attachments:
Description Flags
Patch none

Chris Dumez
Reported 2019-10-01 14:37:12 PDT
XMLHttpRequest sometimes prevents pages from entering the back/forward cache.
Attachments
Patch (5.97 KB, patch)
2019-10-01 15:44 PDT, Chris Dumez 		no flags
DetailsFormatted DiffDiff
View All Add attachment proposed patch, testcase, etc.
Radar WebKit Bug Importer
Comment 1 2019-10-01 14:37:38 PDT
<rdar://problem/55890340>
Chris Dumez
Comment 2 2019-10-01 15:44:32 PDT
Created attachment 379958 [details] Patch
Geoffrey Garen
Comment 3 2019-10-03 13:44:29 PDT
Comment on attachment 379958 [details] Patch r=me Isn't it also the case that the document refuses to cache if it has not fired the load event yet? It seems like tight coupling for an XHR object to maintain invariants on behalf of the document.
Chris Dumez
Comment 4 2019-10-03 13:46:02 PDT
(In reply to Geoffrey Garen from comment #3) > Comment on attachment 379958 [details] > Patch > > r=me > > Isn't it also the case that the document refuses to cache if it has not > fired the load event yet? It seems like tight coupling for an XHR object to > maintain invariants on behalf of the document. It is true for the main frame but not necessarily true for subframes (that were added later on, after the load event had fired in the main frame).
Geoffrey Garen
Comment 5 2019-10-03 13:48:49 PDT
> > Isn't it also the case that the document refuses to cache if it has not > > fired the load event yet? It seems like tight coupling for an XHR object to > > maintain invariants on behalf of the document. > > It is true for the main frame but not necessarily true for subframes (that > were added later on, after the load event had fired in the main frame). If a subframe has not loaded yet, and we cancel its loads in order to enter the page cache, doesn't that present the same concern -- that the subframe document will fire its load event while in the page cache?
Chris Dumez
Comment 6 2019-10-03 13:51:37 PDT
(In reply to Geoffrey Garen from comment #5) > > > Isn't it also the case that the document refuses to cache if it has not > > > fired the load event yet? It seems like tight coupling for an XHR object to > > > maintain invariants on behalf of the document. > > > > It is true for the main frame but not necessarily true for subframes (that > > were added later on, after the load event had fired in the main frame). > > If a subframe has not loaded yet, and we cancel its loads in order to enter > the page cache, doesn't that present the same concern -- that the subframe > document will fire its load event while in the page cache? No, the load event would fire before entering PageCache, which is when we stop the loads. The issue here is that XMLHttpRequest stops its load in the "suspend" function (where script is not allowed to run). This can be refactored further so that XMLHttpRequest no longer stops its loads in suspend though. I can look into it in a follow-up.
Geoffrey Garen
Comment 7 2019-10-03 13:57:58 PDT
Sounds good.
WebKit Commit Bot
Comment 8 2019-10-03 14:29:50 PDT
Comment on attachment 379958 [details] Patch Clearing flags on attachment: 379958 Committed r250678: <https://trac.webkit.org/changeset/250678>
WebKit Commit Bot
Comment 9 2019-10-03 14:29:51 PDT
All reviewed patches have been landed. Closing bug.
Note You need to log in before you can comment on or make changes to this bug.