Version 4.5.103.24 (cherry-pick)

src/heap/mark-compact.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/v8.h"
 
 #include "src/base/atomicops.h"
 #include "src/base/bits.h"
 #include "src/code-stubs.h"
 #include "src/compilation-cache.h"
@@ skipping 3040 matching lines @@
     heap()->IncrementPromotedObjectsSize(object_size);
     return true;
   }
 
   return false;
 }
 
 
 bool MarkCompactCollector::IsSlotInBlackObject(Page* p, Address slot,
                                                HeapObject** out_object) {
-  // This function does not support large objects right now.
   Space* owner = p->owner();
   if (owner == heap_->lo_space() || owner == NULL) {
-    *out_object = NULL;
-    return true;
+    Object* large_object = heap_->lo_space()->FindObject(slot);
+    // This object has to exist, otherwise we would not have recorded a slot
+    // for it.
+    CHECK(large_object->IsHeapObject());
+    HeapObject* large_heap_object = HeapObject::cast(large_object);
+    if (IsMarked(large_heap_object)) {
+      *out_object = large_heap_object;
+      return true;
+    }
+    return false;
   }
 
   uint32_t mark_bit_index = p->AddressToMarkbitIndex(slot);
   unsigned int start_index = mark_bit_index >> Bitmap::kBitsPerCellLog2;
   MarkBit::CellType index_in_cell = 1U
                                     << (mark_bit_index & Bitmap::kBitIndexMask);
   MarkBit::CellType* cells = p->markbits()->cells();
   Address cell_base = p->area_start();
   unsigned int cell_base_start_index = Bitmap::IndexToCell(
       Bitmap::CellAlignIndex(p->AddressToMarkbitIndex(cell_base)));
@@ skipping 96 matching lines @@
 
 bool MarkCompactCollector::IsSlotInLiveObject(Address slot) {
   HeapObject* object = NULL;
   // The target object is black but we don't know if the source slot is black.
   // The source object could have died and the slot could be part of a free
   // space. Find out based on mark bits if the slot is part of a live object.
   if (!IsSlotInBlackObject(Page::FromAddress(slot), slot, &object)) {
     return false;
   }
 
-  // |object| is NULL only when the slot belongs to large object space.
-  DCHECK(object != NULL ||
-         Page::FromAnyPointerAddress(heap_, slot)->owner() ==
-             heap_->lo_space());
-  // We don't need to check large objects' layout descriptor since it can't
-  // contain in-object fields anyway.
-  if (object != NULL) {
+  DCHECK(object != NULL);
+
     switch (object->ContentType()) {
       case HeapObjectContents::kTaggedValues:
         return true;
 
       case HeapObjectContents::kRawValues: {
         InstanceType type = object->map()->instance_type();
         // Slots in maps and code can't be invalid because they are never
         // shrunk.
         if (type == MAP_TYPE || type == CODE_TYPE) return true;
 
         // Consider slots in objects that contain ONLY raw data as invalid.
         return false;
       }
 
       case HeapObjectContents::kMixedValues: {
         if (object->IsFixedTypedArrayBase()) {
           return static_cast<int>(slot - object->address()) ==
                  FixedTypedArrayBase::kBasePointerOffset;
         } else if (FLAG_unbox_double_fields) {
           // Filter out slots that happen to point to unboxed double fields.
           LayoutDescriptorHelper helper(object->map());
           DCHECK(!helper.all_fields_tagged());
           return helper.IsTagged(static_cast<int>(slot - object->address()));
         }
         break;
       }
     }
     UNREACHABLE();
-  }
-
-  return true;
+    return true;
 }
 
 
 void MarkCompactCollector::VerifyIsSlotInLiveObject(Address slot,
                                                     HeapObject* object) {
   // The target object has to be black.
   CHECK(Marking::IsBlack(Marking::MarkBitFrom(object)));
 
   // The target object is black but we don't know if the source slot is black.
   // The source object could have died and the slot could be part of a free
@@ skipping 1207 matching lines @@
              ->NeverEvacuate());
 
   while (buffer != NULL) {
     SlotsBuffer::ObjectSlot* slots = buffer->slots_;
     intptr_t slots_count = buffer->idx_;
 
     for (int slot_idx = 0; slot_idx < slots_count; ++slot_idx) {
       ObjectSlot slot = slots[slot_idx];
       if (!IsTypedSlot(slot)) {
         Object* object = *slot;
-        if (object->IsHeapObject()) {
-          if (heap->InNewSpace(object) ||
-              !heap->mark_compact_collector()->IsSlotInLiveObject(
-                  reinterpret_cast<Address>(slot))) {
-            slots[slot_idx] = kRemovedEntry;
-          }
+        if ((object->IsHeapObject() && heap->InNewSpace(object)) ||
+            !heap->mark_compact_collector()->IsSlotInLiveObject(
+                reinterpret_cast<Address>(slot))) {
+          slots[slot_idx] = kRemovedEntry;
         }
       } else {
         ++slot_idx;
         DCHECK(slot_idx < slots_count);
       }
     }
     buffer = buffer->next();
   }
 }
 
@@ skipping 36 matching lines @@
 void SlotsBuffer::VerifySlots(Heap* heap, SlotsBuffer* buffer) {
   while (buffer != NULL) {
     SlotsBuffer::ObjectSlot* slots = buffer->slots_;
     intptr_t slots_count = buffer->idx_;
 
     for (int slot_idx = 0; slot_idx < slots_count; ++slot_idx) {
       ObjectSlot slot = slots[slot_idx];
       if (!IsTypedSlot(slot)) {
         Object* object = *slot;
         if (object->IsHeapObject()) {
+          HeapObject* heap_object = HeapObject::cast(object);
           CHECK(!heap->InNewSpace(object));
-          CHECK(heap->mark_compact_collector()->IsSlotInLiveObject(
-              reinterpret_cast<Address>(slot)));
+          heap->mark_compact_collector()->VerifyIsSlotInLiveObject(
+              reinterpret_cast<Address>(slot), heap_object);
         }
       } else {
         ++slot_idx;
         DCHECK(slot_idx < slots_count);
       }
     }
     buffer = buffer->next();
   }
 }
 
@@ skipping 131 matching lines @@
   SlotsBuffer* buffer = *buffer_address;
   while (buffer != NULL) {
     SlotsBuffer* next_buffer = buffer->next();
     DeallocateBuffer(buffer);
     buffer = next_buffer;
   }
   *buffer_address = NULL;
 }
 }  // namespace internal
 }  // namespace v8