Bug 213705

Summary:

RunLoop::dispatch should only call wakeUp when needed

Product:

WebKit

Reporter:

Geoffrey Garen <ggaren>

Component:

New Bugs

Assignee:

Geoffrey Garen <ggaren>

Status:

RESOLVED FIXED

Severity:

Normal

CC:

andersca, beidson, benjamin, cdumez, cmarcelo, ews-watchlist, sam, sihui_liu, webkit-bug-importer

Priority:

Keywords:

InRadar

Version:

WebKit Nightly Build

Hardware:

Unspecified

OS:

Unspecified

Attachments:

Description	Flags
Patch	none
Patch	none
Patch	none
Patch	none
Patch	none
Patch	none

Geoffrey Garen

Reported 2020-06-28 16:05:09 PDT

RunLoop::dispatch should only call wakeUp when needed

Attachments
Patch (1.63 KB, patch) 2020-06-28 16:06 PDT, Geoffrey Garen	no flags	Details Formatted Diff Diff
Patch (4.94 KB, patch) 2020-06-28 16:33 PDT, Geoffrey Garen	no flags	Details Formatted Diff Diff
Patch (2.94 KB, patch) 2020-06-28 21:28 PDT, Geoffrey Garen	no flags	Details Formatted Diff Diff
Patch (2.98 KB, patch) 2020-06-30 21:54 PDT, Geoffrey Garen	no flags	Details Formatted Diff Diff
Patch (7.01 KB, patch) 2020-07-01 21:24 PDT, Geoffrey Garen	no flags	Details Formatted Diff Diff
Patch (8.88 KB, patch) 2020-07-02 15:34 PDT, Geoffrey Garen	no flags	Details Formatted Diff Diff
Show Obsolete (5) View All Add attachment proposed patch, testcase, etc.

Geoffrey Garen

Comment 1 2020-06-28 16:06:25 PDT

Created attachment 403013 [details] Patch

Geoffrey Garen

Comment 2 2020-06-28 16:09:01 PDT

Comment on attachment 403013 [details] Patch Oops! I had planned to remove the functionsHandled behavior separately from this patch -- but it's actually not correct until you do both, since functionsHandled is willing to exit without a wakeUp. :(

Geoffrey Garen

Comment 3 2020-06-28 16:33:11 PDT

Created attachment 403014 [details] Patch

Sam Weinig

Comment 4 2020-06-28 17:23:51 PDT

Comment on attachment 403014 [details] Patch View in context: https://bugs.webkit.org/attachment.cgi?id=403014&action=review > Source/WTF/ChangeLog:10 > + RunLoop::wakeUp is super expensive (at least on Darwin platforms). Back > + when IndexedDB used RunLoop::dispatch, RunLoop::wakeUp accounted for 15% > + of all database lookup time. Out of interest (and for the historical record) what makes it so expensive?

Geoffrey Garen

Comment 5 2020-06-28 20:03:25 PDT

Most of the cost seemed to be its usage of pthread mutexes.

Sam Weinig

Comment 6 2020-06-28 20:22:36 PDT

(In reply to Geoffrey Garen from comment #5) > Most of the cost seemed to be its usage of pthread mutexes. Is "its" here CFRunLoopWakeUp()? Or something we are doing in WTF?

Geoffrey Garen

Comment 7 2020-06-28 21:28:24 PDT

Created attachment 403027 [details] Patch

Geoffrey Garen

Comment 8 2020-06-28 21:29:09 PDT

> Is "its" here CFRunLoopWakeUp()? Or something we are doing in WTF? It's CFRunLoopSourceSignal and CFRunLoopWakeUp.

Geoffrey Garen

Comment 9 2020-06-30 21:54:01 PDT

Created attachment 403264 [details] Patch

Geoffrey Garen

Comment 10 2020-07-01 21:24:48 PDT

Created attachment 403343 [details] Patch