• Shu-yu Guo's avatar
    [shared-struct] Fix external pointers to WaiterQueueNodes · df59f217
    Shu-yu Guo authored
    WaiterQueueNodes as used by JS synchronization primitives are per-main
    thread, and external pointer handles to those nodes are 1-1. That
    1-1-ness is captured by each main thread Isolate having a
    waiter_queue_node_external_pointer_ field.
    
    The current logic is incorrect on unlock paths as the Isolate that
    requested the unlock can point its own
    waiter_queue_node_external_pointer_ to another Isolate's
    WaiterQueueNode. This CL fixes this by having each WaiterQueueNode hold onto its own external pointer handle.
    
    This CL also fixes an embarrassing bug where the WaiterQueueNode was not correctly dequeued on timeout.
    
    Bug: v8:13189, v8:12547
    Change-Id: I8db16ae6d653d2e71989ad003faae20fcee06a25
    Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3832298
    Commit-Queue: Shu-yu Guo <syg@chromium.org>
    Reviewed-by: 's avatarJakob Kummerow <jkummerow@chromium.org>
    Reviewed-by: 's avatarSamuel Groß <saelo@chromium.org>
    Cr-Commit-Position: refs/heads/main@{#82601}
    df59f217
js-atomics-synchronization.cc 20.5 KB