src/hotspot/share/gc/g1/g1ParScanThreadState.inline.hpp

@@ -23,10 +23,11 @@
  */
 
 #ifndef SHARE_VM_GC_G1_G1PARSCANTHREADSTATE_INLINE_HPP
 #define SHARE_VM_GC_G1_G1PARSCANTHREADSTATE_INLINE_HPP
 
+#include "gc/g1/g1CollectedHeap.inline.hpp"
 #include "gc/g1/g1ParScanThreadState.hpp"
 #include "gc/g1/g1RemSet.hpp"
 #include "oops/access.inline.hpp"
 #include "oops/oop.inline.hpp"
 

@@ -38,24 +39,28 @@
   // set, due to (benign) races in the claim mechanism during RSet scanning more
   // than one thread might claim the same card. So the same card may be
   // processed multiple times, and so we might get references into old gen here.
   // So we need to redo this check.
   const InCSetState in_cset_state = _g1h->in_cset_state(obj);
-  if (in_cset_state.is_in_cset()) {
+  // References pushed onto the work stack should never point to a humongous region
+  // as they are not added to the collection set due to above precondition.
+  assert(!in_cset_state.is_humongous(),
+         "Obj " PTR_FORMAT " should not refer to humongous region %u from " PTR_FORMAT,
+         p2i(obj), _g1h->addr_to_region((HeapWord*)obj), p2i(p));
+
+  if (!in_cset_state.is_in_cset()) {
+    // In this case somebody else already did all the work.
+    return;
+  }
+
     markOop m = obj->mark_raw();
     if (m->is_marked()) {
       obj = (oop) m->decode_pointer();
     } else {
       obj = copy_to_survivor_space(in_cset_state, obj, m);
     }
     RawAccess<IS_NOT_NULL>::oop_store(p, obj);
-  } else if (in_cset_state.is_humongous()) {
-    _g1h->set_humongous_is_live(obj);
-  } else {
-    assert(in_cset_state.is_default(),
-           "In_cset_state must be NotInCSet here, but is " CSETSTATE_FORMAT, in_cset_state.value());
-  }
 
   assert(obj != NULL, "Must be");
   if (!HeapRegion::is_in_same_region(p, obj)) {
     HeapRegion* from = _g1h->heap_region_containing(p);
     update_rs(from, p, obj);