RFR: 7160924: jvmti: GetPhase returns incorrect phase before VMInit event is issued
Daniel D. Daugherty
daniel.daugherty at oracle.com
Thu Apr 12 07:31:01 PDT 2012
I want to take a closer look at the failing test...
Be back soon...
On 4/12/12 8:03 AM, Karen Kinnear wrote:
> I hear your point, there is a comment in the VM Initialization Event that "In the case of VM start-up
> failure, this event will not be sent".
> That said, the goal of the VM initialization event is to inform the agent that it is free
> to call any JNI or JMVTI function. Many agents want to be able to start tracking the VM as early as possible.
> So there is a trade-off in how early you send this event and risks of VM failures after we send it.
> To maximize benefits to users of the API, the current trade-off is to declare the VM initialized, i.e. in live phase,
> and to post the VM Initialization event as soon as we meet the agents' needs.
> Yes, it is possible for the VM to exit later, both on additional subsystem startup operations and of course
> due to things like out of memory errors at any time. So the "consistency" is that if we have a failure
> in starting up the VM for the operations critical to jvmti agents, we exit without sending the event. For
> failures later during startup and beyond, we don't. Bootstrapping is a very delicate process and
> we want to optimize for the agents starting as early as they can for the success cases.
> While longer term we would like to improve our ability to recover from some of the memory errors,
> I think the trade-off of empowering the agents to be functional as early as we can is the right balance
> at this time.
> So - I would support the bug fix as is.
> On Apr 12, 2012, at 9:12 AM, Dmitry Samersoff wrote:
>> As far as I understand the code, after your changes we will
>> post JVMTI event
>> ever if later JVM aborts on some error.
>> I'm not sure it's a good idea because in couple of other
>> places we abort VM without sending the event, so
>> behavior of agent become inconsistent.
>> On 2012-04-12 16:12, Rickard Bäckman wrote:
>>> can I get review for this small change? The issue is that if we are
>>> running tracing startup code inbetween setting the phase to
>>> JVMTI_PHASE_LIVE and posting the VMInit event.
>>> CR: http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=7160924
>> Dmitry Samersoff
>> Java Hotspot development team, SPB04
>> * There will come soft rains ...
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