code review request for Redefine and Retransform Classes memory leak (7121600, 7122253)

[Daniel D. Daugherty]

Coleen,

Thanks for the quick review!

I don't think it would be too hard to refactor that code, but
I would prefer not to for a couple of reasons:

- the JDK6u29 version will likely be pushed as an escalation fix
   and refactoring is frowned upon unless absolutely necessary
- for ease of determining correctness with all three versions,
   they should remain as similar as possible

Are you OK with this resolution? Please let me know.

Dan


On 12/21/11 2:06 PM, Coleen Phillimore wrote:
>
> Dan, I reviewed one of the hotspot versions and it looks good to me.  
> I have one request that the code in parseClassFile in the conditional  
> JvmtiExport::should_post_class_file_load_hook() { ... } be made into 
> it's own function because it's not the straight line case and is 
> getting to be a larger block of code.  If it's not hard to do.
> We still want to know how you found it... very impressive!
>
> Thanks,
> Coleen
>
> On 12/21/2011 2:09 PM, Daniel D. Daugherty wrote:
>> Greetings,
>>
>> This is a code review request for "day one" memory leaks in
>> the java.lang.instrument.Instrumentation.redefineClasses()
>> and JVM/TI RetransformClasses() APIs.
>>
>> Since one leak is in the JDK and the other leak is in the
>> VM, I'm sending out separate webrevs for each repo. I'm also
>> attacking these leaks in three releases in parallel so there
>> is a pair of webrevs for: JDK6u29, JDK7u4 and JDK8. Yes, I'm
>> trying to get this all done before Christmas!
>>
>> Here are the bug links:
>>
>>     7121600 2/3 Instrumentation.redefineClasses() leaks class bytes
>>     http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=7121600
>>     http://monaco.sfbay.sun.com/detail.jsp?cr=7121600
>>
>>     7122253 2/3 Instrumentation.retransformClasses() leaks class bytes
>>     http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=7121600
>>     http://monaco.sfbay.sun.com/detail.jsp?cr=7122253
>>
>> I don't know why the bugs.sun.com links aren't showing up yet...
>>
>> I think it is best to review the JDK7u4/HSX-23-B06 webrevs first.
>>
>> Here are the webrevs for the JDK6u29/HSX-20 version of the fixes:
>>
>>     http://cr.openjdk.java.net/~dcubed/7121600-webrev/1-jdk6u29/
>>     http://cr.openjdk.java.net/~dcubed/7122253-webrev/0-hsx20/
>>
>> I expect the OpenJDK6 version of the fixes to very similar if not
>> identical to the JDK6u29 version. I haven't been tracking the
>> OpenJDK6 project as closely as I used to so I don't know whether
>> these fixes should go back there also.
>>
>> Here are the webrevs for the JDK7u4/HSX-23-B06 version of the fixes:
>>
>>     http://cr.openjdk.java.net/~dcubed/7121600-webrev/1-jdk7u4/
>>     http://cr.openjdk.java.net/~dcubed/7122253-webrev/0-hsx23-b06/
>>
>> The JDK7u4 JLI code has some other, unrelated fixes relative to
>> the JDK6u29 JLI code. That required a very minor change in my fix
>> to JPLISAgent.c to insulate against unexpected JVM/TI phase values
>> in a slightly different way than the original JDK7u4 code.
>>
>> Also, JDK7u4 was updated to the HSX-23-B08 snapshot last night, but
>> I baselined and tested the fix against HSX-23-B06 so I'm sending out
>> the webrev for what I actually used.
>>
>> Here are the webrevs for the JDK8/HSX-23-B08 version of the fixes:
>>
>>     http://cr.openjdk.java.net/~dcubed/7121600-webrev/1-jdk8/
>>     http://cr.openjdk.java.net/~dcubed/7122253-webrev/0-hsx23-b08/
>>
>> The JDK7u4 and JDK8 versions of the fix for 7121600 are identical.
>> The HSX-23-B06 and HSX-23-B08 versions of the fix for 7122253 are
>> also identical.
>>
>> I've run the following test suites:
>>
>> - VM/NSK jvmti, VM/NSK jvmti_unit
>> - VM/NSK jdwp
>> - SDK/JDK com/sun/jdi, SDK/JDK closed/com/sun/jdi, VM/NSK jdi
>> - SDK/JDK java/lang/instrument
>> - VM/NSK hprof, VM/NSK jdb, VM/NSK sajdi
>> - VM/NSK heapdump
>> - SDK/JDK misc_attach, SDK/JDK misc_jvmstat, SDK/JDK misc_tools
>>
>> on the following configs:
>>
>> - {Client VM, Server VM} x {product, fastdebug} x {-Xmixed, -Xcomp}
>> - Solaris X86 JDK6u29/HSX-20 (done - no regressions)
>> - Solaris X86 JDK7u4/HSX-23-B06 (done - no regressions)
>> - WinXP JDK7u4/HSX-23-B06 (in process, no regressions so far)
>> - Solaris X86 JDK8/HSX-23-B08 (just started)
>> - WinXP JDK8/HSX-23-B08 (not yet started)
>>
>> Thanks, in advance, for any feedback...
>>
>> Dan
>>