RFR (S) JDK-8007725 - Klass::restore_unshareable_info() triggers assert(k->java_mirror() == NULL)

[Coleen Phillimore]

This looks good.   Thank you for fixing it.
Coleen

On 03/14/2013 01:49 AM, Ioi Lam wrote:
> Hi, could someone review this? This fixes a crash related to OOM 
> handling.
>
> Thanks
> - Ioi
>
> On 03/11/2013 12:47 PM, Ioi Lam wrote:
>> Please review:
>> http://cr.openjdk.java.net/~iklam/8007725/null_mirror_001/
>>
>> Bug: NPG: Klass::restore_unshareable_info() triggers
>>     assert(k->java_mirror() == NULL)
>>
>> http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=8007725
>>  or https://jbs.oracle.com/bugs/browse/JDK-8007725
>>
>>     (The bugs.sun.com page may be unavailable for a couple of days due
>>      to recent change of confidentiality status.)
>>
>> Summary of fix:
>>
>>     The assert is at:
>>
>>     --------
>>     # Internal Error (src/share/vm/classfile/javaClasses.cpp:527)
>>     # assert(k->java_mirror() == NULL) failed: should only assign 
>> mirror once
>>     java_lang_Class::create_mirror(KlassHandle)
>>     Klass::restore_unshareable_info()
>>     InstanceKlass::restore_unshareable_info()
>>     instanceKlassHandle 
>> SystemDictionary::load_shared_class(instanceKlassHandle,Handle)
>>     --------
>>
>>     This happens if during class loading, an OOM happened after
>>     Klass::restore_unshareable_info() has called
>>     java_lang_Class::create_mirror(), but before the class loading is 
>> completed.
>>
>>     At this point, the class is not in the system dictionary. However 
>> the
>>     Klass structure is partially initialized.
>>
>>     If the app tries to load the same class again, the assert happens.
>>
>>     The fix is to undo all work performed by
>>     InstanceKlass::restore_unshareable_info().
>>
>> Tests executed:
>>
>>     * JPRT
>>     * JCK (vm, lang, api/signaturetest)
>>     * UTE (vm.quick.testlist, )
>>
>> Thanks,
>> Ioi
>