Bug 133103 - operationOptimize() should defer the GC for a while
Summary: operationOptimize() should defer the GC for a while
Status: RESOLVED FIXED
Alias: None
Product: WebKit
Classification: Unclassified
Component: JavaScriptCore (show other bugs)
Version: 528+ (Nightly build)
Hardware: Unspecified Unspecified
: P2 Normal
Assignee: Mark Lam
URL:
Keywords: InRadar
Depends on:
Blocks:
 
Reported: 2014-05-19 18:34 PDT by Mark Lam
Modified: 2014-05-19 19:04 PDT (History)
7 users (show)

See Also:

Attachments
the patch. (3.10 KB, patch)
2014-05-19 18:58 PDT, Mark Lam 		fpizlo: review+
Details | Formatted Diff | Diff
View All Add an attachment (proposed patch, testcase, etc.)

Note You need to log in before you can comment on or make changes to this bug.
Description Mark Lam 2014-05-19 18:34:21 PDT 
Currently, operationOptimize() only defers the GC until its end.  As a result, a GC may be triggered before we return from operationOptimize(), and it may jettison the optimize codeBlock that we're planning to OSR enter into when we return from this function.  This is because the OSR entry on-ramp code hasn't been executed yet, and hence, there is not yet a reference to this new codeBlock from the stack, and there won't be until we've had a chance to return out of operationOptimize() and run the OSR entry on-ramp code.

This issue can be fixed by using DeferGCForAWhile instead of DeferGC.  This ensures that the GC will be deferred until after the OSR entry on-ramp can be executed.
Comment 1 Mark Lam 2014-05-19 18:35:52 PDT 
<rdar://problem/16738067>
Comment 2 Mark Lam 2014-05-19 18:58:18 PDT 
Created attachment 231747 [details]
the patch.
Comment 3 Mark Lam 2014-05-19 19:04:45 PDT 
Thanks.  Landed in r169094: <http://trac.webkit.org/r169094>