object_registry.h revision d35776413901a6a9d478e06dc354ea4f7d962e04 
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 <jni.h>
21#include <stdint.h>
22
23#include <map>
24
25#include "jdwp/jdwp.h"
26#include "safe_map.h"
27
28namespace art {
29
30namespace mirror {
31  class Object;
32  class Class;
33}  // namespace mirror
34
35struct ObjectRegistryEntry {
36  // Is jni_reference a weak global or a regular global reference?
37  jobjectRefType jni_reference_type;
38
39  // The reference itself.
40  jobject jni_reference;
41
42  // A reference count, so we can implement DisposeObject.
43  int32_t reference_count;
44
45  // The corresponding id, so we only need one map lookup in Add.
46  JDWP::ObjectId id;
47
48  // The identity hash code of the object. This is the same as the key
49  // for object_to_entry_. Store this for DisposeObject().
50  int32_t identity_hash_code;
51};
52std::ostream& operator<<(std::ostream& os, const ObjectRegistryEntry& rhs);
53
54// Tracks those objects currently known to the debugger, so we can use consistent ids when
55// referring to them. Normally we keep JNI weak global references to objects, so they can
56// still be garbage collected. The debugger can ask us to retain objects, though, so we can
57// also promote references to regular JNI global references (and demote them back again if
58// the debugger tells us that's okay).
59class ObjectRegistry {
60 public:
61  ObjectRegistry();
62
63  JDWP::ObjectId Add(mirror::Object* o)
64      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) LOCKS_EXCLUDED(Locks::thread_list_lock_);
65  JDWP::RefTypeId AddRefType(mirror::Class* c)
66      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) LOCKS_EXCLUDED(Locks::thread_list_lock_);
67
68  template<typename T> T Get(JDWP::ObjectId id) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
69    if (id == 0) {
70      return NULL;
71    }
72    return reinterpret_cast<T>(InternalGet(id));
73  }
74
75  bool Contains(mirror::Object* o) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
76    return Contains(o, nullptr);
77  }
78
79  void Clear() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
80
81  void DisableCollection(JDWP::ObjectId id) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
82  void EnableCollection(JDWP::ObjectId id) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
83
84  bool IsCollected(JDWP::ObjectId id) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
85
86  void DisposeObject(JDWP::ObjectId id, uint32_t reference_count)
87      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
88
89  // Returned by Get when passed an invalid object id.
90  static mirror::Object* const kInvalidObject;
91
92  // This is needed to get the jobject instead of the Object*.
93  // Avoid using this and use standard Get when possible.
94  jobject GetJObject(JDWP::ObjectId id) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
95
96 private:
97  JDWP::ObjectId InternalAdd(mirror::Object* o)
98      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) LOCKS_EXCLUDED(Locks::thread_list_lock_);
99  mirror::Object* InternalGet(JDWP::ObjectId id) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
100  void Demote(ObjectRegistryEntry& entry) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, lock_);
101  void Promote(ObjectRegistryEntry& entry) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, lock_);
102  bool Contains(mirror::Object* o, ObjectRegistryEntry** out_entry)
103      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
104  bool ContainsLocked(Thread* self, mirror::Object* o, int32_t identity_hash_code,
105                      ObjectRegistryEntry** out_entry)
106      EXCLUSIVE_LOCKS_REQUIRED(lock_) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
107
108  Mutex lock_ DEFAULT_MUTEX_ACQUIRED_AFTER;
109  std::multimap<int32_t, ObjectRegistryEntry*> object_to_entry_ GUARDED_BY(lock_);
110  SafeMap<JDWP::ObjectId, ObjectRegistryEntry*> id_to_entry_ GUARDED_BY(lock_);
111
112  size_t next_id_ GUARDED_BY(lock_);
113};
114
115}  // namespace art
116
117#endif  // ART_RUNTIME_JDWP_OBJECT_REGISTRY_H_
118