1 /*
2  * Copyright (C) 2011 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_MIRROR_OBJECT_ARRAY_H_
18 #define ART_RUNTIME_MIRROR_OBJECT_ARRAY_H_
19 
20 #include <iterator>
21 #include "array.h"
22 #include "base/iteration_range.h"
23 #include "obj_ptr.h"
24 
25 namespace art {
26 namespace mirror {
27 
28 template<typename T, typename Container> class ArrayIter;
29 template <typename T> using ConstObjPtrArrayIter = ArrayIter<T, const ObjPtr<ObjectArray<T>>>;
30 template <typename T> using ConstHandleArrayIter = ArrayIter<T, const Handle<ObjectArray<T>>>;
31 template <typename T> using ObjPtrArrayIter = ArrayIter<T, ObjPtr<ObjectArray<T>>>;
32 template <typename T> using HandleArrayIter = ArrayIter<T, Handle<ObjectArray<T>>>;
33 
34 template<class T>
35 class MANAGED ObjectArray: public Array {
36  public:
37   // The size of Object[].class.
ClassSize(PointerSize pointer_size)38   static uint32_t ClassSize(PointerSize pointer_size) {
39     return Array::ClassSize(pointer_size);
40   }
41 
42   static ObjPtr<ObjectArray<T>> Alloc(Thread* self,
43                                       ObjPtr<Class> object_array_class,
44                                       int32_t length,
45                                       gc::AllocatorType allocator_type)
46       REQUIRES_SHARED(Locks::mutator_lock_) REQUIRES(!Roles::uninterruptible_);
47 
48   static ObjPtr<ObjectArray<T>> Alloc(Thread* self,
49                                       ObjPtr<Class> object_array_class,
50                                       int32_t length)
51       REQUIRES_SHARED(Locks::mutator_lock_) REQUIRES(!Roles::uninterruptible_);
52 
53   template<VerifyObjectFlags kVerifyFlags = kDefaultVerifyFlags,
54            ReadBarrierOption kReadBarrierOption = kWithReadBarrier>
55   ALWAYS_INLINE ObjPtr<T> Get(int32_t i) REQUIRES_SHARED(Locks::mutator_lock_);
56 
57   // Returns true if the object can be stored into the array. If not, throws
58   // an ArrayStoreException and returns false.
59   // TODO fix thread safety analysis: should be REQUIRES_SHARED(Locks::mutator_lock_).
60   template<VerifyObjectFlags kVerifyFlags = kDefaultVerifyFlags>
61   bool CheckAssignable(ObjPtr<T> object) NO_THREAD_SAFETY_ANALYSIS;
62 
63   ALWAYS_INLINE void Set(int32_t i, ObjPtr<T> object) REQUIRES_SHARED(Locks::mutator_lock_);
64   // TODO fix thread safety analysis: should be REQUIRES_SHARED(Locks::mutator_lock_).
65   template<bool kTransactionActive, bool kCheckTransaction = true,
66       VerifyObjectFlags kVerifyFlags = kDefaultVerifyFlags>
67   ALWAYS_INLINE void Set(int32_t i, ObjPtr<T> object) NO_THREAD_SAFETY_ANALYSIS;
68 
69   // Set element without bound and element type checks, to be used in limited
70   // circumstances, such as during boot image writing.
71   // TODO fix thread safety analysis broken by the use of template. This should be
72   // REQUIRES_SHARED(Locks::mutator_lock_).
73   template<bool kTransactionActive, bool kCheckTransaction = true,
74       VerifyObjectFlags kVerifyFlags = kDefaultVerifyFlags>
75   ALWAYS_INLINE void SetWithoutChecks(int32_t i, ObjPtr<T> object) NO_THREAD_SAFETY_ANALYSIS;
76   // TODO fix thread safety analysis broken by the use of template. This should be
77   // REQUIRES_SHARED(Locks::mutator_lock_).
78   template<bool kTransactionActive, bool kCheckTransaction = true,
79       VerifyObjectFlags kVerifyFlags = kDefaultVerifyFlags>
80   ALWAYS_INLINE void SetWithoutChecksAndWriteBarrier(int32_t i, ObjPtr<T> object)
81       NO_THREAD_SAFETY_ANALYSIS;
82 
83   template<VerifyObjectFlags kVerifyFlags = kDefaultVerifyFlags,
84            ReadBarrierOption kReadBarrierOption = kWithReadBarrier>
85   ALWAYS_INLINE ObjPtr<T> GetWithoutChecks(int32_t i) REQUIRES_SHARED(Locks::mutator_lock_);
86 
87   // Copy src into this array (dealing with overlaps as memmove does) without assignability checks.
88   void AssignableMemmove(int32_t dst_pos,
89                          ObjPtr<ObjectArray<T>> src,
90                          int32_t src_pos,
91                          int32_t count)
92       REQUIRES_SHARED(Locks::mutator_lock_);
93 
94   // Copy src into this array assuming no overlap and without assignability checks.
95   void AssignableMemcpy(int32_t dst_pos,
96                         ObjPtr<ObjectArray<T>> src,
97                         int32_t src_pos,
98                         int32_t count)
99       REQUIRES_SHARED(Locks::mutator_lock_);
100 
101   // Copy src into this array with assignability checks.
102   template<bool kTransactionActive>
103   void AssignableCheckingMemcpy(int32_t dst_pos,
104                                 ObjPtr<ObjectArray<T>> src,
105                                 int32_t src_pos,
106                                 int32_t count,
107                                 bool throw_exception)
108       REQUIRES_SHARED(Locks::mutator_lock_);
109 
110   static ObjPtr<ObjectArray<T>> CopyOf(Handle<ObjectArray<T>> h_this,
111                                        Thread* self,
112                                        int32_t new_length)
113       REQUIRES_SHARED(Locks::mutator_lock_)
114       REQUIRES(!Roles::uninterruptible_);
115 
116   static MemberOffset OffsetOfElement(int32_t i);
117 
118   inline ConstObjPtrArrayIter<T> cbegin() const REQUIRES_SHARED(Locks::mutator_lock_);
119   inline ConstObjPtrArrayIter<T> cend() const REQUIRES_SHARED(Locks::mutator_lock_);
ConstIterate()120   inline IterationRange<ConstObjPtrArrayIter<T>> ConstIterate() const REQUIRES_SHARED(Locks::mutator_lock_) {
121     return IterationRange(cbegin(), cend());
122   }
123   inline ObjPtrArrayIter<T> begin() REQUIRES_SHARED(Locks::mutator_lock_);
124   inline ObjPtrArrayIter<T> end() REQUIRES_SHARED(Locks::mutator_lock_);
Iterate()125   inline IterationRange<ObjPtrArrayIter<T>> Iterate() REQUIRES_SHARED(Locks::mutator_lock_) {
126     return IterationRange(begin(), end());
127   }
128 
129   static inline ConstHandleArrayIter<T> cbegin(const Handle<ObjectArray<T>>& h_this)
130       REQUIRES_SHARED(Locks::mutator_lock_);
131   static inline ConstHandleArrayIter<T> cend(const Handle<ObjectArray<T>>& h_this)
132       REQUIRES_SHARED(Locks::mutator_lock_);
ConstIterate(const Handle<ObjectArray<T>> & h_this)133   static inline IterationRange<ConstHandleArrayIter<T>> ConstIterate(
134       const Handle<ObjectArray<T>>& h_this) REQUIRES_SHARED(Locks::mutator_lock_) {
135     return IterationRange(cbegin(h_this), cend(h_this));
136   }
137   static inline HandleArrayIter<T> begin(Handle<ObjectArray<T>>& h_this)
138       REQUIRES_SHARED(Locks::mutator_lock_);
139   static inline HandleArrayIter<T> end(Handle<ObjectArray<T>>& h_this)
140       REQUIRES_SHARED(Locks::mutator_lock_);
Iterate(Handle<ObjectArray<T>> & h_this)141   static inline IterationRange<HandleArrayIter<T>> Iterate(Handle<ObjectArray<T>>& h_this)
142       REQUIRES_SHARED(Locks::mutator_lock_) {
143     return IterationRange(begin(h_this), end(h_this));
144   }
145 
146  private:
147   // TODO fix thread safety analysis broken by the use of template. This should be
148   // REQUIRES_SHARED(Locks::mutator_lock_).
149   template<typename Visitor>
150   void VisitReferences(const Visitor& visitor) NO_THREAD_SAFETY_ANALYSIS;
151 
152   friend class Object;  // For VisitReferences
153   DISALLOW_IMPLICIT_CONSTRUCTORS(ObjectArray);
154 };
155 
156 // Everything is NO_THREAD_SAFETY_ANALYSIS to work-around STL incompat with thread-annotations.
157 // Everything should have REQUIRES_SHARED(Locks::mutator_lock_).
158 template <typename T, typename Container>
159 class ArrayIter : public std::iterator<std::forward_iterator_tag, ObjPtr<T>> {
160  private:
161   using Iter = ArrayIter<T, Container>;
162 
163  public:
ArrayIter(Container array,int32_t idx)164   ArrayIter(Container array, int32_t idx) NO_THREAD_SAFETY_ANALYSIS : array_(array), idx_(idx) {
165     CheckIdx();
166   }
167 
168   ArrayIter(const Iter& other) = default;  // NOLINT(runtime/explicit)
169   Iter& operator=(const Iter& other) = default;
170 
171   bool operator!=(const Iter& other) const NO_THREAD_SAFETY_ANALYSIS {
172     CheckIdx();
173     return !(*this == other);
174   }
175   bool operator==(const Iter& other) const NO_THREAD_SAFETY_ANALYSIS {
176     return Ptr(other.array_) == Ptr(array_) && other.idx_ == idx_;
177   }
178   Iter& operator++() NO_THREAD_SAFETY_ANALYSIS {
179     idx_++;
180     CheckIdx();
181     return *this;
182   }
183   Iter operator++(int) NO_THREAD_SAFETY_ANALYSIS {
184     Iter res(this);
185     idx_++;
186     CheckIdx();
187     return res;
188   }
189   ObjPtr<T> operator->() const NO_THREAD_SAFETY_ANALYSIS {
190     CheckIdx();
191     return array_->GetWithoutChecks(idx_);
192   }
193   ObjPtr<T> operator*() const NO_THREAD_SAFETY_ANALYSIS {
194     CheckIdx();
195     return array_->GetWithoutChecks(idx_);
196   }
197 
198  private:
199   // Checks current index and that locks are properly held.
200   void CheckIdx() const REQUIRES_SHARED(Locks::mutator_lock_);
201 
Ptr(const Handle<ObjectArray<T>> & p)202   static ObjectArray<T>* Ptr(const Handle<ObjectArray<T>>& p)
203       REQUIRES_SHARED(Locks::mutator_lock_) {
204     return p.Get();
205   }
Ptr(const ObjPtr<ObjectArray<T>> & p)206   static ObjectArray<T>* Ptr(const ObjPtr<ObjectArray<T>>& p)
207       REQUIRES_SHARED(Locks::mutator_lock_) {
208     return p.Ptr();
209   }
210 
211   Container array_;
212   int32_t idx_;
213 };
214 
215 }  // namespace mirror
216 }  // namespace art
217 
218 #endif  // ART_RUNTIME_MIRROR_OBJECT_ARRAY_H_
219