RFR: 8166145: runtime/threads/ThreadInterruptTest3 fails with ExitCode 0

[Gerard Ziemski]

hi all,

Please review this straightforward fix for a regression caused by JDK-8138760

For JDK-8138760 we added more debug info to help us understand the "Performance bug: SystemDictionary” issue. That, however, caused a regression in tests that could not account for the new info printed out, such as tests using golden file to compare their output, and those that searched output for keywords like “Error”, which now matched on output that printed entries of Symbol Table like “java.lang.VirtualMachineError, loader NULL class_loader”.

In this fix we wrap the extra debug info in a new “hashtables” UL tag, which means that in order to get the new debug info a test must now pass "-Xlog:hashtables=info” into VM at startup. I filed JDK-8166848 to track followup issue, like finding an optimization that would solve this performance issue and finding an appropriate test dedicated to tracking the issue and verifying the fix.

The new debug info is refactored into its own method “printPerformanceInfoDetails”

We also make a small change to the “verify_lookup_length” method, which now takes the name of the table, instead of hardcoding it to “SymbolTable”.

bug:	https://bugs.openjdk.java.net/browse/JDK-8166145
webrev: http://cr.openjdk.java.net/~gziemski/8166145_rev1

Passes local tonga ThreadInterruptTest3 test and RBT hotspot_all