Add intrinsic for Reference.get()
Added an intrinsic function for Reference.get(). Return immediately
without going through JNI if the slow path is not currently in use.
Otherwise, branch off to the the existing JNI function.
Approximately 47x speedup for cases where slow path is not enabled.
Change-Id: I13ad65a356fe4e104d8d83980694dc2740d7d039
diff --git a/runtime/gc/reference_processor.h b/runtime/gc/reference_processor.h
index 2771ea8..91328a3 100644
--- a/runtime/gc/reference_processor.h
+++ b/runtime/gc/reference_processor.h
@@ -30,6 +30,7 @@
namespace mirror {
class Object;
class Reference;
+class ReferenceClass;
} // namespace mirror
namespace gc {
@@ -49,6 +50,7 @@
SHARED_LOCKS_REQUIRED(Locks::mutator_lock_)
EXCLUSIVE_LOCKS_REQUIRED(Locks::heap_bitmap_lock_)
LOCKS_EXCLUDED(lock_);
+ // The slow path bool is contained in the reference class object, can only be set once
// Only allow setting this with mutators suspended so that we can avoid using a lock in the
// GetReferent fast path as an optimization.
void EnableSlowPath() EXCLUSIVE_LOCKS_REQUIRED(Locks::mutator_lock_);
@@ -60,7 +62,7 @@
IsHeapReferenceMarkedCallback* is_marked_callback, void* arg)
SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
void UpdateRoots(IsMarkedCallback* callback, void* arg)
- SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_);
+ SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_);
private:
class ProcessReferencesArgs {
@@ -75,8 +77,10 @@
MarkObjectCallback* mark_callback_;
void* arg_;
};
+ bool SlowPathEnabled() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
// Called by ProcessReferences.
- void DisableSlowPath(Thread* self) EXCLUSIVE_LOCKS_REQUIRED(lock_);
+ void DisableSlowPath(Thread* self) EXCLUSIVE_LOCKS_REQUIRED(lock_)
+ SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
// If we are preserving references it means that some dead objects may become live, we use start
// and stop preserving to block mutators using GetReferrent from getting access to these
// referents.
@@ -84,8 +88,6 @@
void StopPreservingReferences(Thread* self) LOCKS_EXCLUDED(lock_);
// Process args, used by the GetReferent to return referents which are already marked.
ProcessReferencesArgs process_references_args_ GUARDED_BY(lock_);
- // Boolean for whether or not we need to go slow path in GetReferent.
- volatile bool slow_path_enabled_;
// Boolean for whether or not we are preserving references (either soft references or finalizers).
// If this is true, then we cannot return a referent (see comment in GetReferent).
bool preserving_references_ GUARDED_BY(lock_);