Bug 211264

Summary: Introduce MainThreadNeverDestroyed / MainThreadLazyNeverDestroyed
Product: WebKit Reporter: Yusuke Suzuki <ysuzuki>
Component: DOMAssignee: Yusuke Suzuki <ysuzuki>
Status: RESOLVED FIXED    
Severity: Normal CC: aboxhall, annulen, apinheiro, benjamin, calvaris, cdumez, cfleizach, cmarcelo, dino, dmazzoni, dstockwell, eric.carlson, esprehn+autocc, ews-watchlist, fmalita, fujii.hironori, glenn, gyuyoung.kim, hta, japhet, jcraig, jdiggs, jer.noble, kangil.han, kondapallykalyan, luiz, mark.lam, mifenton, mmaxfield, noam, pdr, philipj, ryuan.choi, sabouhallawa, samuel_white, schenney, sergio, simon.fraser, tommyw, webkit-bug-importer
Priority: P2 Keywords: InRadar
Version: WebKit Nightly Build   
Hardware: Unspecified   
OS: Unspecified   
See Also: https://bugs.webkit.org/show_bug.cgi?id=211365
Bug Depends on: 211355    
Bug Blocks:    
Attachments:
Description Flags
Patch
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mark.lam: review+
Patch
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Yusuke Suzuki
Reported 2020-04-30 16:18:38 PDT
They ensure that access and construction are done in the main thread.
Attachments
Patch (162.49 KB, patch)
2020-04-30 19:06 PDT, Yusuke Suzuki 		no flags
DetailsFormatted DiffDiff
Patch (162.50 KB, patch)
2020-04-30 19:10 PDT, Yusuke Suzuki 		mark.lam: review+
DetailsFormatted DiffDiff
Patch (141.49 KB, patch)
2020-04-30 19:47 PDT, Yusuke Suzuki 		no flags
DetailsFormatted DiffDiff
Patch (141.71 KB, patch)
2020-04-30 20:02 PDT, Yusuke Suzuki 		no flags
DetailsFormatted DiffDiff
Patch (141.93 KB, patch)
2020-04-30 20:26 PDT, Yusuke Suzuki 		no flags
DetailsFormatted DiffDiff
Patch (142.03 KB, patch)
2020-04-30 20:48 PDT, Yusuke Suzuki 		no flags
DetailsFormatted DiffDiff
Patch (142.12 KB, patch)
2020-05-01 01:42 PDT, Yusuke Suzuki 		no flags
DetailsFormatted DiffDiff
Patch (142.13 KB, patch)
2020-05-01 09:50 PDT, Yusuke Suzuki 		no flags
DetailsFormatted DiffDiff
Show Obsolete (4) View All Add attachment proposed patch, testcase, etc.
Yusuke Suzuki
Comment 1 2020-04-30 19:06:25 PDT
Created attachment 398139 [details] Patch
Yusuke Suzuki
Comment 2 2020-04-30 19:10:44 PDT
Created attachment 398141 [details] Patch
Mark Lam
Comment 3 2020-04-30 19:24:50 PDT
Comment on attachment 398141 [details] Patch r=me.
Fujii Hironori
Comment 4 2020-04-30 19:35:00 PDT
Comment on attachment 398141 [details] Patch View in context: https://bugs.webkit.org/attachment.cgi?id=398141&action=review > Source/WebCore/html/InputTypeNames.cpp:37 > return name; It seems enough to just add ASSERT(isMainThread()). What't the difference? The return type of this function is just AtomString, not MainThreadNeverDestroyed<const AtomString>.
Yusuke Suzuki
Comment 5 2020-04-30 19:42:53 PDT
Comment on attachment 398141 [details] Patch View in context: https://bugs.webkit.org/attachment.cgi?id=398141&action=review >> Source/WebCore/html/InputTypeNames.cpp:37 >> return name; > > It seems enough to just add ASSERT(isMainThread()). > What't the difference? > The return type of this function is just AtomString, not MainThreadNeverDestroyed<const AtomString>. MainThreadNeverDestroyed declaratively says that this should be accessed from the main thread. And `ASSERT(isMainThread())` is automatically inserted by MainThreadNeverDestroyed, instead of manually inserting it to every places. So I think this prevents us from using AtomString from the main thread accidentally, and this tells good thread-affinity information to readers of the code explicitly :)
Yusuke Suzuki
Comment 6 2020-04-30 19:47:02 PDT
Created attachment 398146 [details] Patch Patch for landing, resolved Saam's comment
Yusuke Suzuki
Comment 7 2020-04-30 20:02:52 PDT
Created attachment 398148 [details] Patch Patch for landing, resolved Saam's comment
Yusuke Suzuki
Comment 8 2020-04-30 20:26:31 PDT
Created attachment 398152 [details] Patch Patch for landing, resolved Saam's comment
Yusuke Suzuki
Comment 9 2020-04-30 20:48:37 PDT
Created attachment 398155 [details] Patch Patch for landing, fixing iOS build
Yusuke Suzuki
Comment 10 2020-05-01 01:34:54 PDT
Comment on attachment 398155 [details] Patch View in context: https://bugs.webkit.org/attachment.cgi?id=398155&action=review > Source/WTF/wtf/text/AtomString.cpp:137 > +WTF_EXPORT_PRIVATE MainThreadLazyNeverDestroyed<const AtomString> nullAtomData; > +WTF_EXPORT_PRIVATE MainThreadLazyNeverDestroyed<const AtomString> emptyAtomData; Crash looks like due to nullAtom and emptyAtom. But they are specially OK Atoms since those definitions are the same and can be shared between multiple threads (since they are not actually registered in AtomStringTable). I'll slightly modify to handle them specially (just using LazyNeverDestroyed<>) to see the results.
Yusuke Suzuki
Comment 11 2020-05-01 01:42:15 PDT
Created attachment 398168 [details] Patch Patch for landing, fixing Windows builds and Debug crash due to nullAtom & emptyAtom
Yusuke Suzuki
Comment 12 2020-05-01 09:50:27 PDT
Created attachment 398192 [details] Patch Patch for landing, fixing Windows builds and Debug crash due to nullAtom & emptyAtom
Yusuke Suzuki
Comment 13 2020-05-01 12:47:47 PDT
Committed r261013: <https://trac.webkit.org/changeset/261013>
Radar WebKit Bug Importer
Comment 14 2020-05-01 12:48:17 PDT
<rdar://problem/62742993>
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