RFR 8243572: Multiple tests fail with assert(cld->klasses() != 0LL) failed: unexpected NULL for cld->klasses()
harold.seigel at oracle.com
Tue Apr 28 17:27:46 UTC 2020
Please review this fix for JDK-8243572 and JDK-8243336. Both failures
were caused by calling function ClassLoaderData::klasses() and expecting
a non-null return value. However, when the CLD had no classes then NULL
was returned causing the assertion failure in one case and SIGSEGV in
Function klasses() was called in these places to determine if the
ClassLoaderData was for a hidden class or an unsafe anonymous class.
This was done during CLD statistics collection and for JFR events
Since the JDK has replaced uses of unsafe anonymous classes with hidden
classes, there should be very few unsafe anonymous classes. So, it was
decided (with mgronlun and mchung) that the VM and JFR need no longer
distinguish between hidden and unsafe anonymous classes when gathering
CLD statistics and when CLD's are displayed in JFR events. Instead,
unsafe anonymous classes will be counted as hidden classes for CLD
statistics, and JFR will show CLD's for both hidden and unsafe anonymous
classes as hidden.
JBS Bugs: https://bugs.openjdk.java.net/browse/JDK-8243572 and
The fix was regression tested by running Mach5 tiers 1 and 2 tests and
builds on Linux-x64, Solaris, Windows, and Mac OS X, by running Mach5
tiers 3-5 tests on Linux-x64, and running tier 7 tests multiple times on
Windows and also on Mac OS X. Tier 7 testing on Linux-X64 is in progress.
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