Bug 222302

Summary: Add Options::hangOnVerifyGCError() debugging utility.
Product: WebKit Reporter: Mark Lam <mark.lam>
Component: JavaScriptCoreAssignee: Mark Lam <mark.lam>
Status: RESOLVED WONTFIX    
Severity: Normal CC: ews-watchlist, keith_miller, msaboff, saam, tzagallo, webkit-bug-importer
Priority: P2 Keywords: InRadar
Version: WebKit Nightly Build   
Hardware: Unspecified   
OS: Unspecified   
Attachments:
Description Flags
proposed patch. mark.lam: review-, ews-feeder: commit-queue-

Mark Lam
Reported 2021-02-22 20:54:50 PST
Sometimes, verifyGC errors are intermittent and it takes many runs of the jsc shell to reproduce. A --hangOnVerifyGCError=true option will allow the shell to hang after it dumps its verifyGC error message instead of crashing. With this, we can now run 1000s of iterations of invoking the jsc shell to reproduce the error, and it will hang if it finds the error, thereby allowing us to attach lldb later to do some data inspection.
Attachments
proposed patch. (2.58 KB, patch)
2021-02-22 21:08 PST, Mark Lam 		mark.lam: review-
ews-feeder: commit-queue-
DetailsFormatted DiffDiff
View All Add attachment proposed patch, testcase, etc.
Mark Lam
Comment 1 2021-02-22 21:08:37 PST
Created attachment 421283 [details] proposed patch.
Radar WebKit Bug Importer
Comment 2 2021-03-01 20:55:14 PST
<rdar://problem/74908610>
Saam Barati
Comment 3 2021-03-08 10:29:13 PST
Comment on attachment 421283 [details] proposed patch. View in context: https://bugs.webkit.org/attachment.cgi?id=421283&action=review > Source/JavaScriptCore/ChangeLog:12 > + Sometimes, verifyGC errors are intermittent and it takes many runs of the jsc > + shell to reproduce. A --hangOnVerifyGCError=true option will allow us to run > + an unlimited iterations of invoking the jsc shell to reproduce the error, and it > + will hang when it catches the error. We can then attach lldb later to do some > + data inspection to debug the error. Why not just run lldb in a loop?
Mark Lam
Comment 4 2021-03-08 10:31:41 PST
(In reply to Saam Barati from comment #3) > Why not just run lldb in a loop? I didn't think this was possible. My mistake.
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