APAR status
Closed as program error.
Error description
Error Message: j9shr.1015 * ** ASSERTION FAILED ** at CacheMap.cpp:1476: ((_ccHead->getReaderCount(currentThread) != 0)) . Stack Trace: SH_CacheMap::runEntryPointChecks () from jre/lib/ppc/default/libj9shr26.so SH_CacheMap::findROMClassResource () from jre/lib/ppc/default/libj9shr26.so SH_CacheMap::findAttachedData () from jre/lib/ppc/default/libj9shr26.so SH_CacheMap::findAttachedDataAPI () from jre/lib/ppc/default/libj9shr26.so j9shr_findAttachedData () from jre/lib/ppc/default/libj9shr26.so TR_J9VMBase::getSharedCacheHint () from jre/lib/ppc/default/libj9jit26.so TR_J9VMBase::isSharedCacheHint () from jre/lib/ppc/default/libj9jit26.so jitHookInitializeSendTarget () from jre/lib/ppc/default/libj9jit26.so J9HookDispatch () from jre/lib/ppc/default/libj9hookable26.so initializeMethodRunAddress () from jre/lib/ppc/default/libj9vm26.so internalCreateRAMClassFromROMClassImpl () from jre/lib/ppc/default/libj9vm26.so internalCreateRAMClassFromROMClass () from jre/lib/ppc/default/libj9vm26.so foundROMClass () from jre/lib/ppc/default/libj9vm26.so attemptDynamicClassLoad () from jre/lib/ppc/default/libj9vm26.so internalFindClassUTF8 () from jre/lib/ppc/default/libj9vm26.so internalFindClassString () from jre/lib/ppc/default/libj9vm26.so L14 () from jre/lib/ppc/default/libjclscar_26.so internalFindClassUTF8 () from jre/lib/ppc/default/libj9vm26.so resolveClassRef () from jre/lib/ppc/default/libj9vm26.so L109 () from jre/lib/ppc/default/libj9vm26.so .
Local fix
This problem can be prevented by disabling the shared class cache using -Xshareclasses:none.
Problem summary
When a JVM wants to lock the shared class cache for updating the cache, it must wait for other JVMs to release read-locks on the cache. There is a timeout for waiting, since a crashed or hung JVM may leave a read-lock on the cache. After the timeout, the JVM could assert under certain conditions if the read-locks are not all cleared. In a heavily loaded environment, it can happen there are enough readers attached to the shared cache to exhaust the JVM's timeout period.
Problem conclusion
This defect will be fixed in: 6.0.1 SR2 7.0.0 SR1 . The timeout for locking the cache has been increased sufficiently to allow existing readers to complete their work. Also this particular assertion has been removed as this condition is not fatal.
Temporary fix
Comments
APAR Information
APAR number
IV20330
Reported component name
J9 COMMON CODE
Reported component ID
620700127
Reported release
260
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt
Submitted date
2012-04-27
Closed date
2012-04-27
Last modified date
2012-04-27
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
Fix information
Fixed component name
J9 COMMON CODE
Fixed component ID
620700127
Applicable component levels
R260 PSY
UP
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Document Information
Modified date:
21 February 2022