Add exclusion between instrumentation and GC
Instrumentation calls VisitClasses while exclusive holding the
mutator lock. This can cause deadlocks since VisitClasses needs to
decode JNI weak globals. If the system weak slow path flag is set,
then we wait holding locks while exclusive holding the mutator lock.
This causes a deadlock since the GC cannot acquire the mutator lock
to sweep system weaks.
This fixes a deadlock seen in one of the tracing tests.
Change-Id: I580152118e068a70f309dcc19df4144afec835dd
diff --git a/runtime/gc/heap.h b/runtime/gc/heap.h
index d0d0be3..cc48172 100644
--- a/runtime/gc/heap.h
+++ b/runtime/gc/heap.h
@@ -775,6 +775,8 @@
REQUIRES(Locks::mutator_lock_);
void LogGC(GcCause gc_cause, collector::GarbageCollector* collector);
+ void StartGC(Thread* self, GcCause cause, CollectorType collector_type)
+ REQUIRES(!*gc_complete_lock_);
void FinishGC(Thread* self, collector::GcType gc_type) REQUIRES(!*gc_complete_lock_);
// Create a mem map with a preferred base address.
@@ -1325,6 +1327,7 @@
friend class collector::MarkSweep;
friend class collector::SemiSpace;
friend class ReferenceQueue;
+ friend class ScopedGCCriticalSection;
friend class VerifyReferenceCardVisitor;
friend class VerifyReferenceVisitor;
friend class VerifyObjectVisitor;