object_registry.h revision 412c7fced915fc8d4d5e4166e977d55c809168a6 
1/*
2 * Copyright (C) 2013 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#ifndef ART_RUNTIME_JDWP_OBJECT_REGISTRY_H_
18#define ART_RUNTIME_JDWP_OBJECT_REGISTRY_H_
19
20#include <stdint.h>
21
22#include <map>
23
24#include "jdwp/jdwp.h"
25#include "mirror/art_field-inl.h"
26#include "mirror/class.h"
27#include "mirror/class-inl.h"
28#include "mirror/object-inl.h"
29#include "root_visitor.h"
30#include "safe_map.h"
31
32namespace art {
33
34struct ObjectRegistryEntry {
35  // Is jni_reference a weak global or a regular global reference?
36  jobjectRefType jni_reference_type;
37
38  // The reference itself.
39  jobject jni_reference;
40
41  // A reference count, so we can implement DisposeObject.
42  int32_t reference_count;
43
44  // The corresponding id, so we only need one map lookup in Add.
45  JDWP::ObjectId id;
46};
47std::ostream& operator<<(std::ostream& os, const ObjectRegistryEntry& rhs);
48
49// Tracks those objects currently known to the debugger, so we can use consistent ids when
50// referring to them. Normally we keep JNI weak global references to objects, so they can
51// still be garbage collected. The debugger can ask us to retain objects, though, so we can
52// also promote references to regular JNI global references (and demote them back again if
53// the debugger tells us that's okay).
54class ObjectRegistry {
55 public:
56  ObjectRegistry();
57
58  JDWP::ObjectId Add(mirror::Object* o) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
59  JDWP::RefTypeId AddRefType(mirror::Class* c) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
60
61  template<typename T> T Get(JDWP::ObjectId id) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
62    if (id == 0) {
63      return NULL;
64    }
65    return reinterpret_cast<T>(InternalGet(id));
66  }
67
68  bool Contains(mirror::Object* o) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
69
70  void Clear() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
71
72  void DisableCollection(JDWP::ObjectId id) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
73  void EnableCollection(JDWP::ObjectId id) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
74
75  bool IsCollected(JDWP::ObjectId id) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
76
77  void DisposeObject(JDWP::ObjectId id, uint32_t reference_count)
78      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
79
80  // Returned by Get when passed an invalid object id.
81  static mirror::Object* const kInvalidObject;
82
83  // This is needed to get the jobject instead of the Object*.
84  // Avoid using this and use standard Get when possible.
85  jobject GetJObject(JDWP::ObjectId id) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
86
87  // Visit, objects are treated as system weaks.
88  void UpdateObjectPointers(RootVisitor visitor, void* arg)
89      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
90
91  // We have allow / disallow functionality since we use system weak sweeping logic to update moved
92  // objects inside of the object_to_entry_ map.
93  void AllowNewObjects() LOCKS_EXCLUDED(lock_);
94  void DisallowNewObjects() LOCKS_EXCLUDED(lock_);
95
96 private:
97  JDWP::ObjectId InternalAdd(mirror::Object* o) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
98  mirror::Object* InternalGet(JDWP::ObjectId id) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
99  void Demote(ObjectRegistryEntry& entry) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, lock_);
100  void Promote(ObjectRegistryEntry& entry) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, lock_);
101
102  Mutex lock_ DEFAULT_MUTEX_ACQUIRED_AFTER;
103  bool allow_new_objects_ GUARDED_BY(lock_);
104  ConditionVariable condition_ GUARDED_BY(lock_);
105
106  std::map<mirror::Object*, ObjectRegistryEntry*> object_to_entry_ GUARDED_BY(lock_);
107  SafeMap<JDWP::ObjectId, ObjectRegistryEntry*> id_to_entry_ GUARDED_BY(lock_);
108
109  size_t next_id_ GUARDED_BY(lock_);
110};
111
112}  // namespace art
113
114#endif  // ART_RUNTIME_JDWP_OBJECT_REGISTRY_H_
115