request for review (XS), 6458402: 3 jvmti tests fail with CMS and +ExplicitGCInvokesConcurrent
David.Holmes at oracle.com
Sat Dec 4 03:08:58 UTC 2010
Keith McGuigan said the following on 12/03/10 23:19:
> On Dec 3, 2010, at 3:30 AM, Igor Veresov wrote:
>> You're calling notify_gc_end() while holding the FullGCCount_lock. Is
>> that ok? Would it be more prudent to divert control to the user
>> without holding it?
> The notify_gc_end() call does not divert control to the user -- it
> contains only the code that will trigger a dtrace event (which is a
> no-op as far as the VM is concerned; the OS may notice it though).
> That said, I think it would be a good idea to release the lock before
> calling it and I'll change the code to do that. That way if someone
> adds code to the notify_gc_end() method in the future there won't be any
But if you release the lock before firing the probe the two events can
become distant in time and someone else can see a second "start" probe
fire before they've seen the previous "end" probe fire. That makes it
harder to use the probes to analyse what is happening.
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