archive/jdk
1
0
Fork 0
mirror of https://github.com/openjdk/jdk.git synced 2025-09-17 09:34:38 +02:00
Code Issues Projects Releases Packages Wiki Activity Actions

8253183: Fragile memory barrier selection for some weak memory model platforms

Browse source 
Reviewed-by: dholmes, eosterlund, dcubed
This commit is contained in:
Martin Doerr 2020-09-30 09:03:06 +00:00
parent 8331e63fe4
commit dc3a0f5f88
4 changed files with 23 additions and 21 deletions
Download patch file Download diff file Expand all files Collapse all files

12
src/hotspot/share/runtime/synchronizer.cpp
View file

@ -1105,13 +1105,11 @@ intptr_t ObjectSynchronizer::FastHashCode(Thread* self, oop obj) {
// Separate load of dmw/header above from the loads in
// is_being_async_deflated().
if (support_IRIW_for_not_multiple_copy_atomic_cpu) {
// A non-multiple copy atomic (nMCA) machine needs a bigger
// hammer to separate the load above and the loads below.
OrderAccess::fence();
} else {
OrderAccess::loadload();
}
// dmw/header and _contentions may get written by different threads.
// Make sure to observe them in the same order when having several observers.
OrderAccess::loadload_for_IRIW();
if (monitor->is_being_async_deflated()) {
// But we can't safely use the hash if we detect that async
// deflation has occurred. So we attempt to restore the