src/share/vm/gc_implementation/g1/g1ParScanThreadState.inline.hpp

rev 6626 : imported patch 8035400-move-g1parscanthreadstate-into-own-files
rev 6627 : imported patch 8035400-2-bengt-fixes
rev 6628 : imported patch 8035401-fix-visibility-of-g1parscanthreadstate
rev 6630 : imported patch 8035401-2-another-inline-try

@@ -41,6 +41,113 @@
   } else {
     immediate_rs_update(from, p, tid);
   }
 }
 
+template <class T> void G1ParScanThreadState::do_oop_evac(T* p, HeapRegion* from) {
+  assert(!oopDesc::is_null(oopDesc::load_decode_heap_oop(p)),
+         "Reference should not be NULL here as such are never pushed to the task queue.");
+  oop obj = oopDesc::load_decode_heap_oop_not_null(p);
+
+  // Although we never intentionally push references outside of the collection
+  // 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. So redo this check.
+  if (_g1h->in_cset_fast_test(obj)) {
+    oop forwardee;
+    if (obj->is_forwarded()) {
+      forwardee = obj->forwardee();
+    } else {
+      forwardee = copy_to_survivor_space(obj);
+    }
+    assert(forwardee != NULL, "forwardee should not be NULL");
+    oopDesc::encode_store_heap_oop(p, forwardee);
+  }
+
+  assert(obj != NULL, "Must be");
+  update_rs(from, p, queue_num());
+}
+
+inline void G1ParScanThreadState::do_oop_partial_array(oop* p) {
+  assert(has_partial_array_mask(p), "invariant");
+  oop from_obj = clear_partial_array_mask(p);
+
+  assert(Universe::heap()->is_in_reserved(from_obj), "must be in heap.");
+  assert(from_obj->is_objArray(), "must be obj array");
+  objArrayOop from_obj_array = objArrayOop(from_obj);
+  // The from-space object contains the real length.
+  int length                 = from_obj_array->length();
+
+  assert(from_obj->is_forwarded(), "must be forwarded");
+  oop to_obj                 = from_obj->forwardee();
+  assert(from_obj != to_obj, "should not be chunking self-forwarded objects");
+  objArrayOop to_obj_array   = objArrayOop(to_obj);
+  // We keep track of the next start index in the length field of the
+  // to-space object.
+  int next_index             = to_obj_array->length();
+  assert(0 <= next_index && next_index < length,
+         err_msg("invariant, next index: %d, length: %d", next_index, length));
+
+  int start                  = next_index;
+  int end                    = length;
+  int remainder              = end - start;
+  // We'll try not to push a range that's smaller than ParGCArrayScanChunk.
+  if (remainder > 2 * ParGCArrayScanChunk) {
+    end = start + ParGCArrayScanChunk;
+    to_obj_array->set_length(end);
+    // Push the remainder before we process the range in case another
+    // worker has run out of things to do and can steal it.
+    oop* from_obj_p = set_partial_array_mask(from_obj);
+    push_on_queue(from_obj_p);
+  } else {
+    assert(length == end, "sanity");
+    // We'll process the final range for this object. Restore the length
+    // so that the heap remains parsable in case of evacuation failure.
+    to_obj_array->set_length(end);
+  }
+  _scanner.set_region(_g1h->heap_region_containing_raw(to_obj));
+  // Process indexes [start,end). It will also process the header
+  // along with the first chunk (i.e., the chunk with start == 0).
+  // Note that at this point the length field of to_obj_array is not
+  // correct given that we are using it to keep track of the next
+  // start index. oop_iterate_range() (thankfully!) ignores the length
+  // field and only relies on the start / end parameters.  It does
+  // however return the size of the object which will be incorrect. So
+  // we have to ignore it even if we wanted to use it.
+  to_obj_array->oop_iterate_range(&_scanner, start, end);
+}
+
+template <class T> inline void G1ParScanThreadState::deal_with_reference(T* ref_to_scan) {
+  if (!has_partial_array_mask(ref_to_scan)) {
+    // Note: we can use "raw" versions of "region_containing" because
+    // "obj_to_scan" is definitely in the heap, and is not in a
+    // humongous region.
+    HeapRegion* r = _g1h->heap_region_containing_raw(ref_to_scan);
+    do_oop_evac(ref_to_scan, r);
+  } else {
+    do_oop_partial_array((oop*)ref_to_scan);
+  }
+}
+
+inline void G1ParScanThreadState::dispatch_reference(StarTask ref) {
+  assert(verify_task(ref), "sanity");
+  if (ref.is_narrow()) {
+    deal_with_reference((narrowOop*)ref);
+  } else {
+    deal_with_reference((oop*)ref);
+  }
+}
+
+void G1ParScanThreadState::steal_and_trim_queue(RefToScanQueueSet *task_queues) {
+  StarTask stolen_task;
+  while (task_queues->steal(queue_num(), hash_seed(), stolen_task)) {
+    assert(verify_task(stolen_task), "sanity");
+    dispatch_reference(stolen_task);
+
+    // We've just processed a reference and we might have made
+    // available new entries on the queues. So we have to make sure
+    // we drain the queues as necessary.
+    trim_queue();
+  }
+}
+
 #endif  /* SHARE_VM_GC_IMPLEMENTATION_G1_G1PARSCANTHREADSTATE_INLINE_HPP */