RFR(S): 8058461: serviceability/dcmd/CodelistTest.java and serviceability/dcmd/CompilerQueueTest.java SIGSEGV

Albert albert.noll at oracle.com
Tue Sep 16 08:45:37 UTC 2014

Hi Nils,

please see comments inline.

On 09/16/2014 10:16 AM, Nils Eliasson wrote:
> Hi,
> I would like review of this change that includes three fixes:
> 1) Let Dcmd Compiler.codelist only print alive-nmethods. We ran into 
> crashes when listing zombies and unloaded too. Alive nmethods includes 
> not-entrants so it still gives a pretty good idea about whats in the 
> code cache and what has been used recently.
What was the cause of these crashes? Is the reason that 
nmethod->method() is null?
Would it make sense to print information about zombie methods that don't 
to a crash?

> 2) Take CompileQueue lock when printing queue. It is not enough to be 
> at a safepoint - the compiler threads may still mutate the list 
> causing crashes.
Are we guaranteed to not run into a deadlock when we acquire the lock?

> 3) Relax the parsing of long hex-numbers in the test of codelist. High 
> addresses (sparc) casues NumberFormatExceptions.
> bug: https://bugs.openjdk.java.net/browse/JDK-8058461
> webrev: http://cr.openjdk.java.net/~neliasso/8058461/webrev.04/
> Thanks!
> //Nils

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