review request for 7130319: C2: running with -XX:+PrintOptoAssembly crashes the VM with assert(false) failed: bad tag in log

Paul Hohensee paul.hohensee at
Tue Jan 24 10:03:01 PST 2012

Yes, Authors can review code, all you need is an openjdk name.

In practice, it's not a problem, because the responsible engineer
knows who's capable of doing a review and who isn't.  And you
still need one Reviewer.


On 1/24/12 11:24 AM, Dean Long wrote:
> So that includes Authors?  For some reason I thought you had to be a 
> Committer.
> dl
> On 1/24/2012 6:16 AM, Paul Hohensee wrote:
>> You only need 1 Reviewer, the other doesn't have to be a Reviewer, but
>> does need an openjdk name.
>> Paul
>> On 1/23/12 11:13 PM, David Holmes wrote:
>>> On 24/01/2012 2:09 PM, Dean Long wrote:
>>>> David, thanks for the review. How many reviews do I need before I can
>>>> commit?
>>> Two. Though there seems to be some leeway as to whether both must be 
>>> Reviewers.
>>> David
>>>> dl
>>>> On 1/23/2012 7:01 PM, David Holmes wrote:
>>>>> Looks good to me.
>>>>> David
>>>>> On 24/01/2012 5:25 AM, Dean Long wrote:
>>>>>> The problem is that the VM thread is trying to exit while another
>>>>>> thread is writing to the XML log. The VM thread also wants to write
>>>>>> to the log, but notices the tag stack doesn't match up. A similar
>>>>>> problem came up before (6295565) and the solution was to relax the
>>>>>> assertion if we were shutting down through JNI DestroyJavaVM. The
>>>>>> above change follows that pattern and also allows shutdown
>>>>>> through JVM_Halt.
>>>>>> More details thanks to David Holmes:
>>>>>> "To be clear the VMThread is writing to the log (actually closing 
>>>>>> it) as
>>>>>> part of exit_globals() while executing VM_Exit::doit. This 
>>>>>> happens after
>>>>>> it calls set_vm_exited() so we add that as a guard against doing the
>>>>>> assertion. The problem arises because the CompilerThread was in the
>>>>>> middle of some writing (as part of PrintOptoAssembly) when it 
>>>>>> entered
>>>>>> the safepoint that allows the VM to exit."
>>>>>> dl

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