I think we may have two problems here.
1) The TRACE_START() call has widened the window between
the phase change and the VMInit event posting. Was
there a good reason for calling TRACE_START() from
that location? In other words, did it have to happen
before VMInit was posted for some reason?
2) The parallel nature of the getphase001 test is going to
lead to false failures of the particular test assertion.
See my comments in the bug report for a detailed analysis.
Dan
On 4/12/12 8:31 AM, Daniel D. Daugherty wrote:
I want to take a closer look at the failing test...
Be back soon...
Dan
On 4/12/12 8:03 AM, Karen Kinnear wrote:
Dmitry,
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.
thanks,
Karen
On Apr 12, 2012, at 9:12 AM, Dmitry Samersoff wrote:
Rickard,
As far as I understand the code, after your changes we will
post JVMTI event
JvmtiExport::post_vm_initialized();
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.
-Dmitry
On 2012-04-12 16:12, Rickard Bäckman wrote:
Hi,
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.
Webrev:
http://cr.openjdk.java.net/~rbackman/7160924/webrev/
CR: http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=7160924
Thanks
/R
--
Dmitry Samersoff
Java Hotspot development team, SPB04
* There will come soft rains ...
