RFR: 8218733: SA: CollectedHeap provides broken implementation for used() and capacity()
stefan.karlsson at oracle.com
Mon Feb 11 08:13:47 UTC 2019
Please review this patch to remove the broken implementation of
CollectedHeap used() and capacity() and instead force all GCs to provide
their own implementations.
This was found while running
serviceability/sa/TestHeapDumpForLargeArray.java on an experimental
implementation of heap dumping in ZGC.
ZGC didn't provide a ZCollectedHeap.used() function and
CollectedHeap.used() was used instead at:
// Check weather we should dump the heap as segments
useSegmentedHeapDump = vm.getUniverse().heap().used() >
Because of this we incorrectly did not use segmented heap dumps, and
therefore overflowed later in the code
Aleksey and Roman,
Could you verify that the implementation for Epsilon is correct? I also
haven't implemented capacity for Shenandoah, as the information isn't
trivially available in the ShenandoahHeap SA class. Do you want to fix
it as part of this patch, or should I create a separate RFE for Shenandoah?
More information about the hotspot-gc-dev