# HG changeset patch
# User rkennke
# Date 1550676569 -3600
# Node ID f42c58bab9736b449df26ad166eeaafd83cf89a5
# Parent  46ef4dea49e55d4ee21090c810b373d13441c84e
8203232: Shenandoah: Resolve oops in SATB filter
Reviewed-by: shade

diff -r 46ef4dea49e5 -r f42c58bab973 src/hotspot/share/gc/shenandoah/shenandoahBarrierSet.cpp
--- a/src/hotspot/share/gc/shenandoah/shenandoahBarrierSet.cpp	Wed Feb 20 10:22:46 2019 -0500
+++ b/src/hotspot/share/gc/shenandoah/shenandoahBarrierSet.cpp	Wed Feb 20 16:29:29 2019 +0100
@@ -335,7 +335,7 @@
   // Filter marked objects before hitting the SATB queues. The same predicate would
   // be used by SATBMQ::filter to eliminate already marked objects downstream, but
   // filtering here helps to avoid wasteful SATB queueing work to begin with.
-  if (!_heap->requires_marking(obj)) return;
+  if (!_heap->requires_marking<false>(obj)) return;
 
   Thread* thr = Thread::current();
   if (thr->is_Java_thread()) {
diff -r 46ef4dea49e5 -r f42c58bab973 src/hotspot/share/gc/shenandoah/shenandoahHeap.hpp
--- a/src/hotspot/share/gc/shenandoah/shenandoahHeap.hpp	Wed Feb 20 10:22:46 2019 -0500
+++ b/src/hotspot/share/gc/shenandoah/shenandoahHeap.hpp	Wed Feb 20 16:29:29 2019 +0100
@@ -676,6 +676,7 @@
   void reset_mark_bitmap();
 
   // SATB barriers hooks
+  template<bool RESOLVE>
   inline bool requires_marking(const void* entry) const;
   void force_satb_flush_all_threads();
 
diff -r 46ef4dea49e5 -r f42c58bab973 src/hotspot/share/gc/shenandoah/shenandoahHeap.inline.hpp
--- a/src/hotspot/share/gc/shenandoah/shenandoahHeap.inline.hpp	Wed Feb 20 10:22:46 2019 -0500
+++ b/src/hotspot/share/gc/shenandoah/shenandoahHeap.inline.hpp	Wed Feb 20 16:29:29 2019 +0100
@@ -316,8 +316,13 @@
   }
 }
 
+template<bool RESOLVE>
 inline bool ShenandoahHeap::requires_marking(const void* entry) const {
-  return !_marking_context->is_marked(oop(entry));
+  oop obj = oop(entry);
+  if (RESOLVE) {
+    obj = ShenandoahBarrierSet::resolve_forwarded_not_null(obj);
+  }
+  return !_marking_context->is_marked(obj);
 }
 
 template <class T>
diff -r 46ef4dea49e5 -r f42c58bab973 src/hotspot/share/gc/shenandoah/shenandoahSATBMarkQueueSet.cpp
--- a/src/hotspot/share/gc/shenandoah/shenandoahSATBMarkQueueSet.cpp	Wed Feb 20 10:22:46 2019 -0500
+++ b/src/hotspot/share/gc/shenandoah/shenandoahSATBMarkQueueSet.cpp	Wed Feb 20 16:29:29 2019 +0100
@@ -49,12 +49,9 @@
   return ShenandoahThreadLocalData::satb_mark_queue(t);
 }
 
-static inline bool discard_entry(const void* entry, ShenandoahHeap* heap) {
-  return !heap->requires_marking(entry);
-}
-
+template <bool RESOLVE>
 class ShenandoahSATBMarkQueueFilterFn {
-  ShenandoahHeap* _heap;
+  ShenandoahHeap* const _heap;
 
 public:
   ShenandoahSATBMarkQueueFilterFn(ShenandoahHeap* heap) : _heap(heap) {}
@@ -62,13 +59,17 @@
   // Return true if entry should be filtered out (removed), false if
   // it should be retained.
   bool operator()(const void* entry) const {
-    return discard_entry(entry, _heap);
+    return !_heap->requires_marking<RESOLVE>(entry);
   }
 };
 
 void ShenandoahSATBMarkQueueSet::filter(SATBMarkQueue* queue) {
   assert(_heap != NULL, "SATB queue set not initialized");
-  apply_filter(ShenandoahSATBMarkQueueFilterFn(_heap), queue);
+  if (_heap->has_forwarded_objects()) {
+    apply_filter(ShenandoahSATBMarkQueueFilterFn<true>(_heap), queue);
+  } else {
+    apply_filter(ShenandoahSATBMarkQueueFilterFn<false>(_heap), queue);
+  }
 }
 
 bool ShenandoahSATBMarkQueue::should_enqueue_buffer() {