Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 1 | // Copyright 2015 the V8 project authors. All rights reserved. |
| 2 | // Use of this source code is governed by a BSD-style license that can be |
| 3 | // found in the LICENSE file. |
| 4 | |
| 5 | #ifndef V8_HEAP_SCAVENGER_INL_H_ |
| 6 | #define V8_HEAP_SCAVENGER_INL_H_ |
| 7 | |
| 8 | #include "src/heap/scavenger.h" |
| 9 | |
| 10 | namespace v8 { |
| 11 | namespace internal { |
| 12 | |
| 13 | void Scavenger::ScavengeObject(HeapObject** p, HeapObject* object) { |
| 14 | DCHECK(object->GetIsolate()->heap()->InFromSpace(object)); |
| 15 | |
| 16 | // We use the first word (where the map pointer usually is) of a heap |
| 17 | // object to record the forwarding pointer. A forwarding pointer can |
| 18 | // point to an old space, the code space, or the to space of the new |
| 19 | // generation. |
| 20 | MapWord first_word = object->map_word(); |
| 21 | |
| 22 | // If the first word is a forwarding address, the object has already been |
| 23 | // copied. |
| 24 | if (first_word.IsForwardingAddress()) { |
| 25 | HeapObject* dest = first_word.ToForwardingAddress(); |
| 26 | DCHECK(object->GetIsolate()->heap()->InFromSpace(*p)); |
| 27 | *p = dest; |
| 28 | return; |
| 29 | } |
| 30 | |
Ben Murdoch | 097c5b2 | 2016-05-18 11:27:45 +0100 | [diff] [blame] | 31 | object->GetHeap()->UpdateAllocationSite<Heap::kGlobal>( |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 32 | object, object->GetHeap()->global_pretenuring_feedback_); |
| 33 | |
| 34 | // AllocationMementos are unrooted and shouldn't survive a scavenge |
| 35 | DCHECK(object->map() != object->GetHeap()->allocation_memento_map()); |
| 36 | // Call the slow part of scavenge object. |
| 37 | return ScavengeObjectSlow(p, object); |
| 38 | } |
| 39 | |
Ben Murdoch | 61f157c | 2016-09-16 13:49:30 +0100 | [diff] [blame] | 40 | SlotCallbackResult Scavenger::CheckAndScavengeObject(Heap* heap, |
| 41 | Address slot_address) { |
| 42 | Object** slot = reinterpret_cast<Object**>(slot_address); |
| 43 | Object* object = *slot; |
| 44 | if (heap->InFromSpace(object)) { |
| 45 | HeapObject* heap_object = reinterpret_cast<HeapObject*>(object); |
| 46 | DCHECK(heap_object->IsHeapObject()); |
| 47 | |
| 48 | ScavengeObject(reinterpret_cast<HeapObject**>(slot), heap_object); |
| 49 | |
| 50 | object = *slot; |
| 51 | // If the object was in from space before and is after executing the |
| 52 | // callback in to space, the object is still live. |
| 53 | // Unfortunately, we do not know about the slot. It could be in a |
| 54 | // just freed free space object. |
| 55 | if (heap->InToSpace(object)) { |
| 56 | return KEEP_SLOT; |
| 57 | } |
| 58 | } else { |
| 59 | DCHECK(!heap->InNewSpace(object)); |
| 60 | } |
| 61 | return REMOVE_SLOT; |
| 62 | } |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 63 | |
| 64 | // static |
Ben Murdoch | 61f157c | 2016-09-16 13:49:30 +0100 | [diff] [blame] | 65 | template <PromotionMode promotion_mode> |
| 66 | void StaticScavengeVisitor<promotion_mode>::VisitPointer(Heap* heap, |
| 67 | HeapObject* obj, |
| 68 | Object** p) { |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 69 | Object* object = *p; |
| 70 | if (!heap->InNewSpace(object)) return; |
| 71 | Scavenger::ScavengeObject(reinterpret_cast<HeapObject**>(p), |
| 72 | reinterpret_cast<HeapObject*>(object)); |
| 73 | } |
| 74 | |
| 75 | } // namespace internal |
| 76 | } // namespace v8 |
| 77 | |
| 78 | #endif // V8_HEAP_SCAVENGER_INL_H_ |