Bug 147841

Summary:

Convert all locking and condition variables in WebKit to use fast ParkingLot-based locks and condition variables

Product:

WebKit

Reporter:

Filip Pizlo <fpizlo>

Component:

Web Template Framework

Assignee:

Filip Pizlo <fpizlo>

Status:

RESOLVED FIXED

Severity:

Normal

CC:

barraclough, basile_clement, benjamin, commit-queue, ggaren, mark.lam, mhahnenb, mmirman, msaboff, nrotem, oliver, saam, sam

Priority:

Version:

528+ (Nightly build)

Hardware:

All

OS:

All

Bug Depends on:

147665, 147908, 147986, 148089, 148140, 148493

Bug Blocks:

Attachments:

Description	Flags
ParkingLot-based Condition	none
the patch	mark.lam: review-

Filip Pizlo

Reported 2015-08-10 14:03:01 PDT

The grand plan is: - Make Lock use atomic increments on the fast path and ParkingLot on the slow path. This will make the fast path a lot better and will reduce the memory usage of Lock. - Give Lock and ByteLock the ability to act as their own condition variables. - Create a separate Condition that uses one byte and some ParkingLot magic, for those cases where a separate condition variable is needed. Then we can remove all uses of std::mutex, std::condition_variable, WTF::Mutex, and WTF::ThreadCondition.

Attachments
ParkingLot-based Condition (13.83 KB, patch) 2015-08-13 00:29 PDT, Filip Pizlo	no flags	Details Formatted Diff Diff
the patch (27.07 KB, patch) 2015-08-13 12:09 PDT, Filip Pizlo	mark.lam: review-	Details Formatted Diff Diff
Show Obsolete (2) View All Add attachment proposed patch, testcase, etc.

Filip Pizlo

Comment 1 2015-08-13 00:29:40 PDT

Created attachment 258884 [details] ParkingLot-based Condition

Filip Pizlo

Comment 2 2015-08-13 12:09:25 PDT

Created attachment 258912 [details] the patch This patch is good to go assuming we want to land this separately from the patch that replaces all uses of ThreadCondition/std::condition_variable with this.

WebKit Commit Bot

Comment 3 2015-08-13 12:11:05 PDT

Attachment 258912 [details] did not pass style-queue: ERROR: Source/WTF/wtf/ParkingLot.cpp:561: Place brace on its own line for function definitions. [whitespace/braces] [4] ERROR: Tools/TestWebKitAPI/Tests/WTF/Condition.cpp:68: Place brace on its own line for function definitions. [whitespace/braces] [4] ERROR: Tools/TestWebKitAPI/Tests/WTF/Condition.cpp:83: Place brace on its own line for function definitions. [whitespace/braces] [4] ERROR: Tools/TestWebKitAPI/Tests/WTF/Condition.cpp:91: Place brace on its own line for function definitions. [whitespace/braces] [4] ERROR: Tools/TestWebKitAPI/Tests/WTF/Condition.cpp:115: Place brace on its own line for function definitions. [whitespace/braces] [4] ERROR: Tools/TestWebKitAPI/Tests/WTF/Condition.cpp:122: Place brace on its own line for function definitions. [whitespace/braces] [4] Total errors found: 6 in 11 files If any of these errors are false positives, please file a bug against check-webkit-style.

Mark Lam

Comment 4 2015-08-13 12:19:23 PDT

Comment on attachment 258912 [details] the patch Missing the ChangeLog.

Filip Pizlo

Comment 5 2015-08-13 12:49:07 PDT

Comment on attachment 258912 [details] the patch I will submit this patch to a different bug.

Filip Pizlo

Comment 6 2015-08-19 11:19:59 PDT

OK, I think this is done.

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