Fix the empty checkpoint timeout.
The problem happens when a thread is indirectly blocked on a mutex
that another thread holds and is blocked on a weak ref access.
Add a way to do a dummy wakeup on a thread that's blocked on a mutex
so that the thread will respond to the empty checkpoint request. Do
this for the mutexes that are expected to be held when a weak ref is
accessed. Add a check that detects an unexpected case.
Bug: 33006388
Bug: 12687968
Test: test-art-host.
Change-Id: Iefec69b9a21aa25a928cb31fcf4fb872f867a8c2
diff --git a/runtime/java_vm_ext.cc b/runtime/java_vm_ext.cc
index e0f28ad..a341cdb 100644
--- a/runtime/java_vm_ext.cc
+++ b/runtime/java_vm_ext.cc
@@ -572,7 +572,7 @@
while (!kUseReadBarrier && UNLIKELY(!MayAccessWeakGlobals(self))) {
// Check and run the empty checkpoint before blocking so the empty checkpoint will work in the
// presence of threads blocking for weak ref access.
- self->CheckEmptyCheckpoint();
+ self->CheckEmptyCheckpointFromWeakRefAccess(Locks::jni_weak_globals_lock_);
weak_globals_add_condition_.WaitHoldingLocks(self);
}
IndirectRef ref = weak_globals_.Add(kIRTFirstSegment, obj);
@@ -706,7 +706,7 @@
while (UNLIKELY(!MayAccessWeakGlobals(self))) {
// Check and run the empty checkpoint before blocking so the empty checkpoint will work in the
// presence of threads blocking for weak ref access.
- self->CheckEmptyCheckpoint();
+ self->CheckEmptyCheckpointFromWeakRefAccess(Locks::jni_weak_globals_lock_);
weak_globals_add_condition_.WaitHoldingLocks(self);
}
return weak_globals_.Get(ref);
@@ -731,7 +731,7 @@
while (UNLIKELY(!MayAccessWeakGlobals(self))) {
// Check and run the empty checkpoint before blocking so the empty checkpoint will work in the
// presence of threads blocking for weak ref access.
- self->CheckEmptyCheckpoint();
+ self->CheckEmptyCheckpointFromWeakRefAccess(Locks::jni_weak_globals_lock_);
weak_globals_add_condition_.WaitHoldingLocks(self);
}
// When just checking a weak ref has been cleared, avoid triggering the read barrier in decode