On 24/07/2013 12:21, David Holmes wrote:
On 24/07/2013 7:31 PM, Mandy Chung wrote:
On 7/24/2013 4:50 PM, shanliang wrote:
So we have 2 kinds of issues here:
1) the test related, like Thread state checking, we can fix them in
the test
2) MBean.getThreadCount() issue, we can create a bug to trace it (add
your test case to the bug), and add a workaround (sleep or call 2
times) in the test to make the test pass. Mandy is the expert and
better to get her opinion.
It's probably a race in the VM implementation in determining the thread
count. You will need to diagnose the VM implementation and compare the
thread list and the implementation of getting the thread count (check
hotspot/src/share/vm/services/threadService.cpp)
There is a considerable code path between the point where a terminating
thread causes Thread.join() to be allowed to return, and the point where
the live thread count gets decremented. So using join() does not help
here. Arguably JVMTI should have based its counts around the lifecycle
of the Java thread not the underlying native thread.
It appears, from my reading of the code, that this situation ( a thread
exiting ) should be handled. Or maybe I'm looking at the wrong interface.
JavaThread::exit(...) {
...
ThreadService::current_thread_exiting(this);
...
ensure_join(..)
...
}
So the exiting thread should be removed from the live thread count
before Thread.join returns.
-Chris.
David
-----
Mandy
