RFR: 8253833: mutexLocker assert_locked_or_safepoint should not access VMThread state from non-VM-thread

Coleen Phillimore coleenp at openjdk.java.net
Thu Oct 8 14:54:48 UTC 2020


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On Thu, 8 Oct 2020 14:51:16 GMT, Coleen Phillimore <coleenp at openjdk.org> wrote:

>> It's unsafe for all threads except VM thread to access the current vm operation.
>> This part of the assert is also faulty:
>> If we are not at safepoint and the operation requester (calling thread) would be the owner of the lock do not mean it
>> is safe for current thread.
>> Passes t1-5. (also note VMThread::vm_operation() assert current thread is VM thread, and I have seen no such assert)
>> 
>> Thanks
>
> src/hotspot/share/runtime/mutexLocker.cpp line 173:
> 
>> 171:   if (!Universe::is_fully_initialized()) return;
>> 172:   fatal("must own lock %s", lock->name());
>> 173: }
> 
> You could refactor this like:
> assert_locked_or_safepoint(lock) {
> if (lock->owned_by_self()) return;
> assert_locked_or_safepoint_weak(lock);
> }

Nah, never mind.  It's a short function.

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PR: https://git.openjdk.java.net/jdk/pull/563


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