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_H_ 6 #define V8_HEAP_SCAVENGER_H_ 7 8 #include "src/heap/objects-visiting.h" 9 #include "src/heap/slot-set.h" 10 11 namespace v8 { 12 namespace internal { 13 14 typedef void (*ScavengingCallback)(Map* map, HeapObject** slot, 15 HeapObject* object); 16 17 class Scavenger { 18 public: 19 explicit Scavenger(Heap* heap) : heap_(heap) {} 20 21 // Initializes static visitor dispatch tables. 22 static void Initialize(); 23 24 // Callback function passed to Heap::Iterate etc. Copies an object if 25 // necessary, the object might be promoted to an old space. The caller must 26 // ensure the precondition that the object is (a) a heap object and (b) in 27 // the heap's from space. 28 static inline void ScavengeObject(HeapObject** p, HeapObject* object); 29 static inline SlotCallbackResult CheckAndScavengeObject(Heap* heap, 30 Address slot_address); 31 32 // Slow part of {ScavengeObject} above. 33 static void ScavengeObjectSlow(HeapObject** p, HeapObject* object); 34 35 // Chooses an appropriate static visitor table depending on the current state 36 // of the heap (i.e. incremental marking, logging and profiling). 37 void SelectScavengingVisitorsTable(); 38 39 Isolate* isolate(); 40 Heap* heap() { return heap_; } 41 42 private: 43 Heap* heap_; 44 VisitorDispatchTable<ScavengingCallback> scavenging_visitors_table_; 45 }; 46 47 48 // Helper class for turning the scavenger into an object visitor that is also 49 // filtering out non-HeapObjects and objects which do not reside in new space. 50 class ScavengeVisitor : public ObjectVisitor { 51 public: 52 explicit ScavengeVisitor(Heap* heap) : heap_(heap) {} 53 54 void VisitPointer(Object** p) override; 55 void VisitPointers(Object** start, Object** end) override; 56 57 private: 58 inline void ScavengePointer(Object** p); 59 60 Heap* heap_; 61 }; 62 63 64 // Helper class for turning the scavenger into an object visitor that is also 65 // filtering out non-HeapObjects and objects which do not reside in new space. 66 class StaticScavengeVisitor 67 : public StaticNewSpaceVisitor<StaticScavengeVisitor> { 68 public: 69 static inline void VisitPointer(Heap* heap, HeapObject* object, Object** p); 70 }; 71 72 } // namespace internal 73 } // namespace v8 74 75 #endif // V8_HEAP_SCAVENGER_H_ 76
