A64: Synchronize with r17104.

src/mark-compact.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 20 matching lines @@
 #include "compilation-cache.h"
 #include "cpu-profiler.h"
 #include "deoptimizer.h"
 #include "execution.h"
 #include "gdb-jit.h"
 #include "global-handles.h"
 #include "heap-profiler.h"
 #include "ic-inl.h"
 #include "incremental-marking.h"
 #include "mark-compact.h"
-#include "marking-thread.h"
 #include "objects-visiting.h"
 #include "objects-visiting-inl.h"
 #include "stub-cache.h"
 #include "sweeper-thread.h"
 
 namespace v8 {
 namespace internal {
 
 
 const char* Marking::kWhiteBitPattern = "00";
@@ skipping 33 matching lines @@
     for (Object** current = start; current < end; current++) {
       if ((*current)->IsHeapObject()) {
         HeapObject* object = HeapObject::cast(*current);
         CHECK(heap_->mark_compact_collector()->IsMarked(object));
       }
     }
   }
 
   void VisitEmbeddedPointer(RelocInfo* rinfo) {
     ASSERT(rinfo->rmode() == RelocInfo::EMBEDDED_OBJECT);
-    if (!FLAG_weak_embedded_maps_in_optimized_code || !FLAG_collect_maps ||
-        rinfo->host()->kind() != Code::OPTIMIZED_FUNCTION ||
-        !rinfo->target_object()->IsMap() ||
-        !Map::cast(rinfo->target_object())->CanTransition()) {
+    if (!Code::IsWeakEmbeddedObject(rinfo->host()->kind(),
+                                    rinfo->target_object())) {
       VisitPointer(rinfo->target_object_address());
     }
   }
 
  private:
   Heap* heap_;
 };
 
 
 static void VerifyMarking(Heap* heap, Address bottom, Address top) {
@@ skipping 292 matching lines @@
   return compacting_;
 }
 
 
 void MarkCompactCollector::CollectGarbage() {
   // Make sure that Prepare() has been called. The individual steps below will
   // update the state as they proceed.
   ASSERT(state_ == PREPARE_GC);
   ASSERT(encountered_weak_collections_ == Smi::FromInt(0));
 
+  heap()->allocation_mementos_found_ = 0;
+
   MarkLiveObjects();
   ASSERT(heap_->incremental_marking()->IsStopped());
 
   if (FLAG_collect_maps) ClearNonLiveReferences();
 
   ClearWeakCollections();
 
 #ifdef VERIFY_HEAP
   if (FLAG_verify_heap) {
     VerifyMarking(heap_);
   }
 #endif
 
   SweepSpaces();
 
   if (!FLAG_collect_maps) ReattachInitialMaps();
 
 #ifdef DEBUG
   if (FLAG_verify_native_context_separation) {
     VerifyNativeContextSeparation(heap_);
   }
 #endif
 
 #ifdef VERIFY_HEAP
-  if (FLAG_collect_maps && FLAG_weak_embedded_maps_in_optimized_code &&
-      heap()->weak_embedded_maps_verification_enabled()) {
-    VerifyWeakEmbeddedMapsInOptimizedCode();
+  if (heap()->weak_embedded_objects_verification_enabled()) {
+    VerifyWeakEmbeddedObjectsInOptimizedCode();
   }
   if (FLAG_collect_maps && FLAG_omit_map_checks_for_leaf_maps) {
     VerifyOmittedMapChecks();
   }
 #endif
 
   Finish();
 
   if (marking_parity_ == EVEN_MARKING_PARITY) {
     marking_parity_ = ODD_MARKING_PARITY;
   } else {
     ASSERT(marking_parity_ == ODD_MARKING_PARITY);
     marking_parity_ = EVEN_MARKING_PARITY;
   }
 
+  if (FLAG_trace_track_allocation_sites &&
+      heap()->allocation_mementos_found_ > 0) {
+    PrintF("AllocationMementos found during mark-sweep = %d\n",
+           heap()->allocation_mementos_found_);
+  }
   tracer_ = NULL;
 }
 
 
 #ifdef VERIFY_HEAP
 void MarkCompactCollector::VerifyMarkbitsAreClean(PagedSpace* space) {
   PageIterator it(space);
 
   while (it.has_next()) {
     Page* p = it.next();
@@ skipping 25 matching lines @@
 
   LargeObjectIterator it(heap_->lo_space());
   for (HeapObject* obj = it.Next(); obj != NULL; obj = it.Next()) {
     MarkBit mark_bit = Marking::MarkBitFrom(obj);
     CHECK(Marking::IsWhite(mark_bit));
     CHECK_EQ(0, Page::FromAddress(obj->address())->LiveBytes());
   }
 }
 
 
-void MarkCompactCollector::VerifyWeakEmbeddedMapsInOptimizedCode() {
+void MarkCompactCollector::VerifyWeakEmbeddedObjectsInOptimizedCode() {
   HeapObjectIterator code_iterator(heap()->code_space());
   for (HeapObject* obj = code_iterator.Next();
        obj != NULL;
        obj = code_iterator.Next()) {
     Code* code = Code::cast(obj);
     if (code->kind() != Code::OPTIMIZED_FUNCTION) continue;
     if (WillBeDeoptimized(code)) continue;
-    code->VerifyEmbeddedMapsDependency();
+    code->VerifyEmbeddedObjectsDependency();
   }
 }
 
 
 void MarkCompactCollector::VerifyOmittedMapChecks() {
   HeapObjectIterator iterator(heap()->map_space());
   for (HeapObject* obj = iterator.Next();
        obj != NULL;
        obj = iterator.Next()) {
     Map* map = Map::cast(obj);
@@ skipping 77 matching lines @@
 bool MarkCompactCollector::AreSweeperThreadsActivated() {
   return isolate()->sweeper_threads() != NULL;
 }
 
 
 bool MarkCompactCollector::IsConcurrentSweepingInProgress() {
   return sweeping_pending_;
 }
 
 
-void MarkCompactCollector::MarkInParallel() {
-  for (int i = 0; i < FLAG_marking_threads; i++) {
-    isolate()->marking_threads()[i]->StartMarking();
-  }
-}
-
-
-void MarkCompactCollector::WaitUntilMarkingCompleted() {
-  for (int i = 0; i < FLAG_marking_threads; i++) {
-    isolate()->marking_threads()[i]->WaitForMarkingThread();
-  }
-}
-
-
 bool Marking::TransferMark(Address old_start, Address new_start) {
   // This is only used when resizing an object.
   ASSERT(MemoryChunk::FromAddress(old_start) ==
          MemoryChunk::FromAddress(new_start));
 
   // If the mark doesn't move, we don't check the color of the object.
   // It doesn't matter whether the object is black, since it hasn't changed
   // size, so the adjustment to the live data count will be zero anyway.
   if (old_start == new_start) return false;
 
@@ skipping 846 matching lines @@
         JSWeakCollection::kTableOffset);
     BodyVisitorBase<MarkCompactMarkingVisitor>::IteratePointers(
         map->GetHeap(),
         object,
         JSWeakCollection::kTableOffset + kPointerSize,
         object_size);
 
     // Mark the backing hash table without pushing it on the marking stack.
     Object* table_object = weak_collection->table();
     if (!table_object->IsHashTable()) return;
-    ObjectHashTable* table = ObjectHashTable::cast(table_object);
+    WeakHashTable* table = WeakHashTable::cast(table_object);
     Object** table_slot =
         HeapObject::RawField(weak_collection, JSWeakCollection::kTableOffset);
     MarkBit table_mark = Marking::MarkBitFrom(table);
     collector->RecordSlot(table_slot, table_slot, table);
     if (!table_mark.Get()) collector->SetMark(table, table_mark);
     // Recording the map slot can be skipped, because maps are not compacted.
     collector->MarkObject(table->map(), Marking::MarkBitFrom(table->map()));
     ASSERT(MarkCompactCollector::IsMarked(table->map()));
   }
 
@@ skipping 515 matching lines @@
     while (current_cell != 0) {
       int trailing_zeros = CompilerIntrinsics::CountTrailingZeros(current_cell);
       current_cell >>= trailing_zeros;
       offset += trailing_zeros;
       Address address = cell_base + offset * kPointerSize;
       HeapObject* object = HeapObject::FromAddress(address);
 
       int size = object->Size();
       survivors_size += size;
 
+      if (FLAG_trace_track_allocation_sites && object->IsJSObject()) {
+        if (AllocationMemento::FindForJSObject(JSObject::cast(object), true)
+            != NULL) {
+          heap()->allocation_mementos_found_++;
+        }
+      }
+
       offset++;
       current_cell >>= 1;
       // Aggressively promote young survivors to the old space.
       if (TryPromoteObject(object, size)) {
         continue;
       }
 
       // Promotion failed. Just migrate object to another semispace.
       MaybeObject* allocation = new_space->AllocateRaw(size);
       if (allocation->IsFailure()) {
@@ skipping 79 matching lines @@
 
 
 void MarkCompactCollector::MarkRoots(RootMarkingVisitor* visitor) {
   // Mark the heap roots including global variables, stack variables,
   // etc., and all objects reachable from them.
   heap()->IterateStrongRoots(visitor, VISIT_ONLY_STRONG);
 
   // Handle the string table specially.
   MarkStringTable(visitor);
 
+  MarkWeakObjectToCodeTable();
+
   // There may be overflowed objects in the heap.  Visit them now.
   while (marking_deque_.overflowed()) {
     RefillMarkingDeque();
     EmptyMarkingDeque();
   }
 }
 
 
 void MarkCompactCollector::MarkImplicitRefGroups() {
   List<ImplicitRefGroup*>* ref_groups =
@@ skipping 20 matching lines @@
     }
 
     // Once the entire group has been marked, dispose it because it's
     // not needed anymore.
     delete entry;
   }
   ref_groups->Rewind(last);
 }
 
 
+void MarkCompactCollector::MarkWeakObjectToCodeTable() {
+  HeapObject* weak_object_to_code_table =
+      HeapObject::cast(heap()->weak_object_to_code_table());
+  if (!IsMarked(weak_object_to_code_table)) {
+    MarkBit mark = Marking::MarkBitFrom(weak_object_to_code_table);
+    SetMark(weak_object_to_code_table, mark);
+  }
+}
+
+
 // Mark all objects reachable from the objects on the marking stack.
 // Before: the marking stack contains zero or more heap object pointers.
 // After: the marking stack is empty, and all objects reachable from the
 // marking stack have been marked, or are overflowed in the heap.
 void MarkCompactCollector::EmptyMarkingDeque() {
   while (!marking_deque_.IsEmpty()) {
     HeapObject* object = marking_deque_.Pop();
     ASSERT(object->IsHeapObject());
     ASSERT(heap()->Contains(object));
     ASSERT(Marking::IsBlack(Marking::MarkBitFrom(object)));
@@ skipping 347 matching lines @@
       // Since it survived the GC, reattach it now.
       JSFunction::cast(map->constructor())->shared()->AttachInitialMap(map);
     }
 
     ClearNonLivePrototypeTransitions(map);
     ClearNonLiveMapTransitions(map, map_mark);
 
     if (map_mark.Get()) {
       ClearNonLiveDependentCode(map->dependent_code());
     } else {
-      ClearAndDeoptimizeDependentCode(map);
+      ClearAndDeoptimizeDependentCode(map->dependent_code());
+      map->set_dependent_code(DependentCode::cast(heap()->empty_fixed_array()));
     }
   }
 
   // Iterate over property cell space, removing dependent code that is not
   // otherwise kept alive by strong references.
   HeapObjectIterator cell_iterator(heap_->property_cell_space());
   for (HeapObject* cell = cell_iterator.Next();
        cell != NULL;
        cell = cell_iterator.Next()) {
     if (IsMarked(cell)) {
       ClearNonLiveDependentCode(PropertyCell::cast(cell)->dependent_code());
     }
   }
+
+  if (heap_->weak_object_to_code_table()->IsHashTable()) {
+    WeakHashTable* table =
+        WeakHashTable::cast(heap_->weak_object_to_code_table());
+    uint32_t capacity = table->Capacity();
+    for (uint32_t i = 0; i < capacity; i++) {
+      uint32_t key_index = table->EntryToIndex(i);
+      Object* key = table->get(key_index);
+      if (!table->IsKey(key)) continue;
+      uint32_t value_index = table->EntryToValueIndex(i);
+      Object* value = table->get(value_index);
+      if (IsMarked(key)) {
+        if (!IsMarked(value)) {
+          HeapObject* obj = HeapObject::cast(value);
+          MarkBit mark = Marking::MarkBitFrom(obj);
+          SetMark(obj, mark);
+        }
+        ClearNonLiveDependentCode(DependentCode::cast(value));
+      } else {
+        ClearAndDeoptimizeDependentCode(DependentCode::cast(value));
+        table->set(key_index, heap_->the_hole_value());
+        table->set(value_index, heap_->the_hole_value());
+      }
+    }
+  }
 }
 
 
 void MarkCompactCollector::ClearNonLivePrototypeTransitions(Map* map) {
   int number_of_transitions = map->NumberOfProtoTransitions();
   FixedArray* prototype_transitions = map->GetPrototypeTransitions();
 
   int new_number_of_transitions = 0;
   const int header = Map::kProtoTransitionHeaderSize;
   const int proto_offset = header + Map::kProtoTransitionPrototypeOffset;
@@ skipping 45 matching lines @@
   // Follow back pointer, check whether we are dealing with a map transition
   // from a live map to a dead path and in case clear transitions of parent.
   bool current_is_alive = map_mark.Get();
   bool parent_is_alive = Marking::MarkBitFrom(parent).Get();
   if (!current_is_alive && parent_is_alive) {
     parent->ClearNonLiveTransitions(heap());
   }
 }
 
 
-void MarkCompactCollector::ClearAndDeoptimizeDependentCode(Map* map) {
+void MarkCompactCollector::ClearAndDeoptimizeDependentCode(
+    DependentCode* entries) {
   DisallowHeapAllocation no_allocation;
-  DependentCode* entries = map->dependent_code();
   DependentCode::GroupStartIndexes starts(entries);
   int number_of_entries = starts.number_of_entries();
   if (number_of_entries == 0) return;
   for (int i = 0; i < number_of_entries; i++) {
     // If the entry is compilation info then the map must be alive,
     // and ClearAndDeoptimizeDependentCode shouldn't be called.
     ASSERT(entries->is_code_at(i));
     Code* code = entries->code_at(i);
 
     if (IsMarked(code) && !code->marked_for_deoptimization()) {
       code->set_marked_for_deoptimization(true);
       have_code_to_deoptimize_ = true;
     }
     entries->clear_at(i);
   }
-  map->set_dependent_code(DependentCode::cast(heap()->empty_fixed_array()));
 }
 
 
 void MarkCompactCollector::ClearNonLiveDependentCode(DependentCode* entries) {
   DisallowHeapAllocation no_allocation;
   DependentCode::GroupStartIndexes starts(entries);
   int number_of_entries = starts.number_of_entries();
   if (number_of_entries == 0) return;
   int new_number_of_entries = 0;
   // Go through all groups, remove dead codes and compact.
@@ skipping 86 matching lines @@
 // to encounter pointers to dead new space objects during traversal of pointers
 // to new space.  We should clear them to avoid encountering them during next
 // pointer iteration.  This is an issue if the store buffer overflows and we
 // have to scan the entire old space, including dead objects, looking for
 // pointers to new space.
 void MarkCompactCollector::MigrateObject(Address dst,
                                          Address src,
                                          int size,
                                          AllocationSpace dest) {
   HEAP_PROFILE(heap(), ObjectMoveEvent(src, dst));
-  // TODO(hpayer): Replace these checks with asserts.
-  CHECK(heap()->AllowedToBeMigrated(HeapObject::FromAddress(src), dest));
-  CHECK(dest != LO_SPACE && size <= Page::kMaxNonCodeHeapObjectSize);
+  ASSERT(heap()->AllowedToBeMigrated(HeapObject::FromAddress(src), dest));
+  ASSERT(dest != LO_SPACE && size <= Page::kMaxNonCodeHeapObjectSize);
   if (dest == OLD_POINTER_SPACE) {
     Address src_slot = src;
     Address dst_slot = dst;
     ASSERT(IsAligned(size, kPointerSize));
 
     for (int remaining = size / kPointerSize; remaining > 0; remaining--) {
       Object* value = Memory::Object_at(src_slot);
 
       Memory::Object_at(dst_slot) = value;
 
@@ skipping 709 matching lines @@
        cell = js_global_property_cell_iterator.Next()) {
     if (cell->IsPropertyCell()) {
       PropertyCell::BodyDescriptor::IterateBody(cell, &updating_visitor);
     }
   }
 
   // Update the head of the native contexts list in the heap.
   updating_visitor.VisitPointer(heap_->native_contexts_list_address());
 
   heap_->string_table()->Iterate(&updating_visitor);
+  updating_visitor.VisitPointer(heap_->weak_object_to_code_table_address());
+  if (heap_->weak_object_to_code_table()->IsHashTable()) {
+    WeakHashTable* table =
+        WeakHashTable::cast(heap_->weak_object_to_code_table());
+    table->Iterate(&updating_visitor);
+    table->Rehash(heap_->undefined_value());
+  }
 
   // Update pointers from external string table.
   heap_->UpdateReferencesInExternalStringTable(
       &UpdateReferenceInExternalStringTableEntry);
 
   if (!FLAG_watch_ic_patching) {
     // Update JSFunction pointers from the runtime profiler.
     heap()->isolate()->runtime_profiler()->UpdateSamplesAfterCompact(
         &updating_visitor);
   }
@@ skipping 843 matching lines @@
   while (buffer != NULL) {
     SlotsBuffer* next_buffer = buffer->next();
     DeallocateBuffer(buffer);
     buffer = next_buffer;
   }
   *buffer_address = NULL;
 }
 
 
 } }  // namespace v8::internal