• Dominik Inführ's avatar
    Reland "[heap] Introduce ParkedSharedMutexGuardIf and use it in compiler" · e9c4ff40
    Dominik Inführ authored
    This is a reland of 4cd856ee
    
    This CL fixes the problem that local_isolate() returned nullptr on
    the main thread.
    
    Original change's description:
    > [heap] Introduce ParkedSharedMutexGuardIf and use it in compiler
    >
    > In some cases it could happen that the concurrent compiler tries to get
    > a shared lock on a mutex that is already exclusively held by the main
    > thread. The background thread will then block itself until the
    > main thread leaves the critical section. If the main thread then also
    > starts a GC while holding the lock, this will result in a deadlock.
    >
    > A GC can't start until the background thread reaches a safepoint and
    > the main thread can't leave the critical section before the GC ran.
    >
    > This CL introduces a new version of SharedMutexGuard named
    > RecursiveSharedMutexGuardIfNeeded. This class will park the thread
    > when blocking is needed and will unpark the thread again as soon as
    > the lock was acquired successfully. This resolves the deadlock on
    > safepointing.
    >
    > Turbofan can then simply use that class internally for
    > MapUpdaterGuardIfNeeded.
    >
    > Bug: v8:10315, chromium:1218318
    > Change-Id: Ice04b222cc979e4905791118caede26e71fca6de
    > Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2953288
    > Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
    > Reviewed-by: Georg Neis <neis@chromium.org>
    > Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
    > Cr-Commit-Position: refs/heads/master@{#75107}
    
    Bug: v8:10315
    Bug: chromium:1218318
    Change-Id: Ic56afb14a537e0cbf412311f11407c1f09278225
    Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2958408Reviewed-by: 's avatarGeorg Neis <neis@chromium.org>
    Reviewed-by: 's avatarMichael Lippautz <mlippautz@chromium.org>
    Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
    Cr-Commit-Position: refs/heads/master@{#75124}
    e9c4ff40
parked-scope.h 3.17 KB