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