Home | History | Annotate | Download | only in jdwp
      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 
     28 namespace art {
     29 
     30 namespace mirror {
     31   class Object;
     32   class Class;
     33 }  // namespace mirror
     34 
     35 struct 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 };
     52 std::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).
     59 class 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   void Clear() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
     76 
     77   void DisableCollection(JDWP::ObjectId id)
     78       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) LOCKS_EXCLUDED(lock_);
     79 
     80   void EnableCollection(JDWP::ObjectId id)
     81       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) LOCKS_EXCLUDED(lock_);
     82 
     83   bool IsCollected(JDWP::ObjectId id)
     84       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) LOCKS_EXCLUDED(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_)
     99       LOCKS_EXCLUDED(lock_, Locks::thread_list_lock_);
    100 
    101   mirror::Object* InternalGet(JDWP::ObjectId id)
    102       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_)
    103       LOCKS_EXCLUDED(lock_);
    104 
    105   void Demote(ObjectRegistryEntry& entry)
    106       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_)
    107       EXCLUSIVE_LOCKS_REQUIRED(lock_);
    108 
    109   void Promote(ObjectRegistryEntry& entry)
    110       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_)
    111       EXCLUSIVE_LOCKS_REQUIRED(lock_);
    112 
    113   bool ContainsLocked(Thread* self, mirror::Object* o, int32_t identity_hash_code,
    114                       ObjectRegistryEntry** out_entry)
    115       EXCLUSIVE_LOCKS_REQUIRED(lock_) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
    116 
    117   Mutex lock_ DEFAULT_MUTEX_ACQUIRED_AFTER;
    118   std::multimap<int32_t, ObjectRegistryEntry*> object_to_entry_ GUARDED_BY(lock_);
    119   SafeMap<JDWP::ObjectId, ObjectRegistryEntry*> id_to_entry_ GUARDED_BY(lock_);
    120 
    121   size_t next_id_ GUARDED_BY(lock_);
    122 };
    123 
    124 }  // namespace art
    125 
    126 #endif  // ART_RUNTIME_JDWP_OBJECT_REGISTRY_H_
    127