Testing with https://github.com/openjdk/jdk/pull/12229 resulted in memory leak reports related to OopMapCache. Example.
Direct leak of 40 byte(s) in 1 object(s) allocated from:
#0 0x7fa997ab89cf in __interceptor_malloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:69
#1 0x7fa99409e79a in os::malloc(unsigned long, MEMFLAGS, NativeCallStack const&) src/hotspot/share/runtime/os.cpp:673
#2 0x7fa991c1c537 in AllocateHeap(unsigned long, MEMFLAGS, NativeCallStack const&, AllocFailStrategy::AllocFailEnum) src/hotspot/share/memory/allocation.cpp:42
#3 0x7fa991c1c537 in AllocateHeap(unsigned long, MEMFLAGS, AllocFailStrategy::AllocFailEnum) src/hotspot/share/memory/allocation.cpp:52
#4 0x7fa9940847d0 in OopMapCacheEntry::allocate_bit_mask() src/hotspot/share/interpreter/oopMapCache.cpp:307
#5 0x7fa9940847d0 in OopMapCacheEntry::set_mask(CellTypeState*, CellTypeState*, int) src/hotspot/share/interpreter/oopMapCache.cpp:354
#6 0x7fa994084968 in OopMapForCacheEntry::fill_stackmap_for_opcodes(BytecodeStream*, CellTypeState*, CellTypeState*, int) src/hotspot/share/interpreter/oopMapCache.cpp:148
#7 0x7fa994084968 in OopMapForCacheEntry::fill_stackmap_for_opcodes(BytecodeStream*, CellTypeState*, CellTypeState*, int) src/hotspot/share/interpreter/oopMapCache.cpp:142
#8 0x7fa992ee878a in GenerateOopMap::interp1(BytecodeStream*) src/hotspot/share/oops/generateOopMap.cpp:1369
#9 0x7fa992ef2562 in GenerateOopMap::interp_bb(BasicBlock*) src/hotspot/share/oops/generateOopMap.cpp:1148
#10 0x7fa99408127e in OopMapForCacheEntry::compute_map(Thread*) src/hotspot/share/interpreter/oopMapCache.cpp:116
#11 0x7fa994085b2f in OopMapCacheEntry::fill(methodHandle const&, int) src/hotspot/share/interpreter/oopMapCache.cpp:342
#12 0x7fa994085b2f in OopMapCacheEntry::fill(methodHandle const&, int) src/hotspot/share/interpreter/oopMapCache.cpp:331
#13 0x7fa994085b2f in OopMapCache::compute_one_oop_map(methodHandle const&, int, InterpreterOopMap*) src/hotspot/share/interpreter/oopMapCache.cpp:611
#14 0x7fa993efe5c2 in Method::mask_for(int, InterpreterOopMap*) src/hotspot/share/oops/method.cpp:321
#15 0x7fa992ada14f in frame::oops_interpreted_do(OopClosure*, RegisterMap const*, bool) const src/hotspot/share/runtime/frame.cpp:946
#16 0x7fa994595a24 in frame::oops_do(OopClosure*, CodeBlobClosure*, RegisterMap const*, DerivedPointerIterationMode) const src/hotspot/share/runtime/frame.hpp:469
#17 0x7fa994595a24 in ShenandoahStackWatermark::process(frame const&, RegisterMap&, void*) src/hotspot/share/gc/shenandoah/shenandoahStackWatermark.cpp:138
#18 0x7fa99468ac0f in StackWatermarkFramesIterator::process_one(void*) src/hotspot/share/runtime/stackWatermark.cpp:101
#19 0x7fa99468ef34 in StackWatermark::start_processing_impl(void*) src/hotspot/share/runtime/stackWatermark.cpp:215
#20 0x7fa994596916 in ShenandoahStackWatermark::start_processing_impl(void*) src/hotspot/share/gc/shenandoah/shenandoahStackWatermark.cpp:117
#21 0x7fa994690e62 in StackWatermark::start_processing() src/hotspot/share/runtime/stackWatermark.cpp:319
#22 0x7fa994690e62 in StackWatermark::start_processing() src/hotspot/share/runtime/stackWatermark.cpp:315
#23 0x7fa994690e62 in StackWatermark::on_safepoint() src/hotspot/share/runtime/stackWatermark.cpp:307
#24 0x7fa99434ed85 in SafepointMechanism::process(JavaThread*, bool, bool) src/hotspot/share/runtime/safepointMechanism.cpp:157
#25 0x7fa99312656c in SafepointMechanism::process_if_requested(JavaThread*, bool, bool) src/hotspot/share/runtime/safepointMechanism.inline.hpp:83
#26 0x7fa99312656c in SafepointMechanism::process_if_requested_with_exit_check(JavaThread*, bool) src/hotspot/share/runtime/safepointMechanism.inline.hpp:88
#27 0x7fa99312656c in ThreadStateTransition::transition_from_vm(JavaThread*, JavaThreadState, bool) src/hotspot/share/runtime/interfaceSupport.inline.hpp:113
#28 0x7fa99312656c in ThreadInVMfromJava::~ThreadInVMfromJava() src/hotspot/share/runtime/interfaceSupport.inline.hpp:140
#29 0x7fa99312656c in InterpreterRuntime::resolve_ldc(JavaThread*, Bytecodes::Code) src/hotspot/share/interpreter/interpreterRuntime.cpp:213
Loooks like temporary OopMapCacheEntry are created in two places in OopMapCache and are free'd directly, failing to call `flush()` before hand leading to leaks.
-------------
Commit messages:
- Fix memory leaks related to OopMapCache
Changes: https://git.openjdk.org/jdk/pull/12230/files
Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=12230&range=00
Issue: https://bugs.openjdk.org/browse/JDK-8301187
Stats: 2 lines in 1 file changed: 2 ins; 0 del; 0 mod
Patch: https://git.openjdk.org/jdk/pull/12230.diff
Fetch: git fetch https://git.openjdk.org/jdk pull/12230/head:pull/12230
PR: https://git.openjdk.org/jdk/pull/12230