Bug 184718

Summary: WebKit::DisplayLink maintains a strong reference to WebPageProxy, creating a reference cycle
Product: WebKit Reporter: Conrad Shultz <conrad_shultz>
Component: WebKit APIAssignee: Conrad Shultz <conrad_shultz>
Status: RESOLVED FIXED    
Severity: Normal CC: commit-queue, conrad_shultz, pvollan, thorton
Priority: P1 Keywords: InRadar
Version: WebKit Nightly Build   
Hardware: Unspecified   
OS: Unspecified   
Attachments:
Description Flags
Patch none

Conrad Shultz
Reported 2018-04-17 17:02:39 PDT
WebKit::DisplayLink maintains a strong reference to WebPageProxy, creating a reference cycle.
Attachments
Patch (2.15 KB, patch)
2018-04-17 17:25 PDT, Conrad Shultz 		no flags
DetailsFormatted DiffDiff
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Conrad Shultz
Comment 1 2018-04-17 17:03:31 PDT
<rdar://problem/39468022>
Conrad Shultz
Comment 2 2018-04-17 17:03:46 PDT
rdar://problem/39468022
Conrad Shultz
Comment 3 2018-04-17 17:04:11 PDT
<rdar://problem/39468022>
Conrad Shultz
Comment 4 2018-04-17 17:06:32 PDT
rdar://problem/39468022
Conrad Shultz
Comment 5 2018-04-17 17:07:45 PDT
rdar://problem/39468022
Conrad Shultz
Comment 6 2018-04-17 17:08:55 PDT
Oops...
Conrad Shultz
Comment 7 2018-04-17 17:25:23 PDT
Created attachment 338167 [details] Patch
Per Arne Vollan
Comment 8 2018-04-17 17:41:18 PDT
Comment on attachment 338167 [details] Patch View in context: https://bugs.webkit.org/attachment.cgi?id=338167&action=review Thanks for finding and fixing this! > Source/WebKit/UIProcess/mac/DisplayLink.cpp:-39 > - : m_webPageProxy(webPageProxy) The address of the WebPageProxy object is passed as a parameter to the function CVDisplayLinkSetOutputCallback below. This pointer is then passed as a void* parameter in the DisplayLink::displayLinkCallback method where it is casted to a WebPageProxy object. If it is guaranteed that we will not receive any callbacks after CVDisplayLinkStop is called in the destructor, then this patch is correct. Otherwise I think we have to use a weak pointer instead.
Tim Horton
Comment 9 2018-04-17 17:44:05 PDT
Comment on attachment 338167 [details] Patch View in context: https://bugs.webkit.org/attachment.cgi?id=338167&action=review >> Source/WebKit/UIProcess/mac/DisplayLink.cpp:-39 >> - : m_webPageProxy(webPageProxy) > > The address of the WebPageProxy object is passed as a parameter to the function CVDisplayLinkSetOutputCallback below. This pointer is then passed as a void* parameter in the DisplayLink::displayLinkCallback method where it is casted to a WebPageProxy object. If it is guaranteed that we will not receive any callbacks after CVDisplayLinkStop is called in the destructor, then this patch is correct. Otherwise I think we have to use a weak pointer instead. Good point
WebKit Commit Bot
Comment 10 2018-04-17 20:07:16 PDT
Comment on attachment 338167 [details] Patch Clearing flags on attachment: 338167 Committed r230747: <https://trac.webkit.org/changeset/230747>
WebKit Commit Bot
Comment 11 2018-04-17 20:07:17 PDT
All reviewed patches have been landed. Closing bug.
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