[webkit-changes] [WebKit/WebKit] 925943: [JSC] Atomics.waitAsync should be invocable from t...

[jjgriego]

  Branch: refs/heads/main
  Home:   https://github.com/WebKit/WebKit
  Commit: 9259434c015156e882dd760a0a0355c5c5d9e3c4
      https://github.com/WebKit/WebKit/commit/9259434c015156e882dd760a0a0355c5c5d9e3c4
  Author: Joseph Griego <jgriego at igalia.com>
  Date:   2023-01-12 (Thu, 12 Jan 2023)

  Changed paths:
    A LayoutTests/js/Atomics-waitasync-invocable-on-main-thread-expected.txt
    A LayoutTests/js/Atomics-waitasync-invocable-on-main-thread.html
    M Source/JavaScriptCore/runtime/AtomicsObject.cpp

  Log Message:
  -----------
  [JSC] Atomics.waitAsync should be invocable from the main thread
https://bugs.webkit.org/show_bug.cgi?id=250518

Reviewed by Keith Miller.

According to the current proposed spec [1], async atomic waits are not
restricted to threads with `AgentCanSuspend()`--so, Atomics.waitAsync should not
throw a TypeError for this reason. I've added a (very simple) test to this
effect.

So, we should delay the check for `isAtomicsWaitAllowedOnCurrentThread` until after we know
the wait is known to be synchronous.

If there's an implementation reason we shouldn't do this, let me know, but I
couldn't find one.

[1] https://tc39.es/proposal-atomics-wait-async/#sec-dowait

* LayoutTests/js/Atomics-waitasync-invocable-on-main-thread-expected.txt: Added.
* LayoutTests/js/Atomics-waitasync-invocable-on-main-thread.html: Added.
* Source/JavaScriptCore/runtime/AtomicsObject.cpp:
(JSC::atomicsWaitImpl):

Canonical link: https://commits.webkit.org/258856@main