Bug 242690 – [WTF] Ensure isMainThread semantics for Linux match Apple/BSD semantics

• Status: RESOLVED
• Resolution: FIXED
• Component: Web Template Framework

[James Hilliard]

It's not entirely clear if the current implementation semantics are fully identical between Linux and Apple/BSD systems. The Apple/BSD pthread_main_np function has 3 potential return values, 1 if the thread is the initial thread, 0 if it is not or -1 if thread is not initialized/unknown, lets make sure we only return true for isMainThread if the return for pthread_main_np is 1. On linux checking if we are on the initial thread can be accomplished by checking the equality of getpid and gettid. Note we use a syscall for calling gettid as the gettid() libc function may not be guaranteed to be supported by all libc's on Linux unlike the syscall(which is also used elsewhere in WebKit).

[James Hilliard]

Pull request: https://github.com/WebKit/WebKit/pull/2363

[EWS]

Committed 252485@main (50d7bfe855ca): <https://commits.webkit.org/252485@main>

Reviewed commits have been landed. Closing PR #2363 and removing active labels.

[Radar WebKit Bug Importer]

<rdar://problem/97048055>

[Adrian Perez]

Reopening to address Darin's comment about usage of pthread_main_np() here:

  https://github.com/WebKit/WebKit/commit/50d7bfe855ca043cc72ec09b3d3d75100015101b#r78597817

[Adrian Perez]

Pull request: https://github.com/WebKit/WebKit/pull/2536

[EWS]

Committed 252601@main (0307ab9b687a): <https://commits.webkit.org/252601@main>

Reviewed commits have been landed. Closing PR #2536 and removing active labels.

[Michael Catanzaro]

Regression: bug #243401