974416 - TSan: data race js/src/vm/ForkJoin.cpp:1538 js::ForkJoinShared::check(js::ForkJoinContext&)

Status: RESOLVED INCOMPLETE

(Core :: JavaScript Engine, defect)

Description

[Christian Holler (:decoder)]

Attachment: Logfile with TSan trace

The attached logfile shows a thread/data race (mozilla-central revision file/tsan-trace100.txt) detected by TSan (ThreadSanitizer).

Typically, races reported by TSan are not false positives, but it is possible that the race is benign. Even in this case though, we should try to come up with a fix unless this would cause inacceptable performance issues. Also note that seemingly benign races can possibly be harmful (also depending on the compiler and the architecture) [1].

If the bug cannot be fixed, then this bug should be used to either make a compile-time annotation for blacklisting or add an entry to the runtime blacklist.

[1] http://software.intel.com/en-us/blogs/2013/01/06/benign-data-races-what-could-possibly-go-wrong

Comment 1

[Christian Holler (:decoder)]

I think the revision here was meant to be 44ba69cacd7e.

Comment 2

[Nathan Froyd [:froydnj]]

ParallelJS has been removed, so this race is no longer present.