| // Copyright (c) 2014, the Dart project authors. Please see the AUTHORS file |
| // for details. All rights reserved. Use of this source code is governed by a |
| // BSD-style license that can be found in the LICENSE file. |
| |
| #ifndef VM_OBJECT_GRAPH_H_ |
| #define VM_OBJECT_GRAPH_H_ |
| |
| #include "vm/allocation.h" |
| #include "vm/object.h" |
| |
| namespace dart { |
| |
| class Isolate; |
| |
| // Utility to traverse the object graph in an ordered fashion. |
| // Example uses: |
| // - find a retaining path from the isolate roots to a particular object, or |
| // - determine how much memory is retained by some particular object(s). |
| class ObjectGraph : public StackResource { |
| public: |
| class Stack; |
| |
| // Allows climbing the search tree all the way to the root. |
| class StackIterator { |
| public: |
| // The object this iterator currently points to. |
| RawObject* Get() const; |
| // Returns false if there is no parent. |
| bool MoveToParent(); |
| private: |
| StackIterator(const Stack* stack, intptr_t index) |
| : stack_(stack), index_(index) { } |
| const Stack* stack_; |
| intptr_t index_; |
| friend class ObjectGraph::Stack; |
| DISALLOW_IMPLICIT_CONSTRUCTORS(StackIterator); |
| }; |
| |
| class Visitor { |
| public: |
| // Directs how the search should continue after visiting an object. |
| enum Direction { |
| kProceed, // Recurse on this object's pointers. |
| kBacktrack, // Ignore this object's pointers. |
| kAbort, // Terminate the entire search immediately. |
| }; |
| virtual ~Visitor() { } |
| // Visits the object pointed to by *it. The iterator is only valid |
| // during this call. This method must not allocate from the heap or |
| // trigger GC in any way. |
| virtual Direction VisitObject(StackIterator* it) = 0; |
| }; |
| |
| explicit ObjectGraph(Isolate* isolate); |
| ~ObjectGraph(); |
| |
| // Visits all strongly reachable objects in the isolate's heap, in a |
| // pre-order, depth first traversal. |
| void IterateObjects(Visitor* visitor); |
| |
| // Like 'IterateObjects', but restricted to objects reachable from 'root' |
| // (including 'root' itself). |
| void IterateObjectsFrom(const Object& root, Visitor* visitor); |
| |
| // The number of bytes retained by 'obj'. |
| intptr_t SizeRetainedByInstance(const Object& obj); |
| |
| // The number of bytes retained by the set of all objects of the given class. |
| intptr_t SizeRetainedByClass(intptr_t class_id); |
| |
| private: |
| DISALLOW_IMPLICIT_CONSTRUCTORS(ObjectGraph); |
| }; |
| |
| } // namespace dart |
| |
| #endif // VM_OBJECT_GRAPH_H_ |