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 "base/macros.h"
24 #include "obj_ptr.h"
25 
26 namespace art HIDDEN {
27 namespace mirror {
28 
29 template<typename T, typename Container> class ArrayIter;
30 template <typename T> using ConstObjPtrArrayIter = ArrayIter<T, const ObjPtr<ObjectArray<T>>>;
31 template <typename T> using ConstHandleArrayIter = ArrayIter<T, const Handle<ObjectArray<T>>>;
32 template <typename T> using ObjPtrArrayIter = ArrayIter<T, ObjPtr<ObjectArray<T>>>;
33 template <typename T> using HandleArrayIter = ArrayIter<T, Handle<ObjectArray<T>>>;
34 
35 template<class T>
36 class MANAGED ObjectArray: public Array {
37  public:
38   MIRROR_CLASS("[Ljava/lang/Object;");
39 
40   // The size of Object[].class.
ClassSize(PointerSize pointer_size)41   static uint32_t ClassSize(PointerSize pointer_size) {
42     return Array::ClassSize(pointer_size);
43   }
44 
45   static ObjPtr<ObjectArray<T>> Alloc(Thread* self,
46                                       ObjPtr<Class> object_array_class,
47                                       int32_t length,
48                                       gc::AllocatorType allocator_type)
49       REQUIRES_SHARED(Locks::mutator_lock_) REQUIRES(!Roles::uninterruptible_);
50 
51   static ObjPtr<ObjectArray<T>> Alloc(Thread* self,
52                                       ObjPtr<Class> object_array_class,
53                                       int32_t length)
54       REQUIRES_SHARED(Locks::mutator_lock_) REQUIRES(!Roles::uninterruptible_);
55 
56   template<VerifyObjectFlags kVerifyFlags = kDefaultVerifyFlags,
57            ReadBarrierOption kReadBarrierOption = kWithReadBarrier>
58   ALWAYS_INLINE ObjPtr<T> Get(int32_t i) REQUIRES_SHARED(Locks::mutator_lock_);
59 
60   // Returns true if the object can be stored into the array. If not, throws
61   // an ArrayStoreException and returns false.
62   // TODO fix thread safety analysis: should be REQUIRES_SHARED(Locks::mutator_lock_).
63   template<VerifyObjectFlags kVerifyFlags = kDefaultVerifyFlags>
64   bool CheckAssignable(ObjPtr<T> object) NO_THREAD_SAFETY_ANALYSIS;
65 
66   ALWAYS_INLINE void Set(int32_t i, ObjPtr<T> object) REQUIRES_SHARED(Locks::mutator_lock_);
67   // TODO fix thread safety analysis: should be REQUIRES_SHARED(Locks::mutator_lock_).
68   template<bool kTransactionActive, bool kCheckTransaction = true,
69       VerifyObjectFlags kVerifyFlags = kDefaultVerifyFlags>
70   ALWAYS_INLINE void Set(int32_t i, ObjPtr<T> object) NO_THREAD_SAFETY_ANALYSIS;
71 
72   // Set element without bound and element type checks, to be used in limited
73   // circumstances, such as during boot image writing.
74   // TODO fix thread safety analysis broken by the use of template. This should be
75   // REQUIRES_SHARED(Locks::mutator_lock_).
76   template<bool kTransactionActive, bool kCheckTransaction = true,
77       VerifyObjectFlags kVerifyFlags = kDefaultVerifyFlags>
78   ALWAYS_INLINE void SetWithoutChecks(int32_t i, ObjPtr<T> object) NO_THREAD_SAFETY_ANALYSIS;
79   // TODO fix thread safety analysis broken by the use of template. This should be
80   // REQUIRES_SHARED(Locks::mutator_lock_).
81   template<bool kTransactionActive, bool kCheckTransaction = true,
82       VerifyObjectFlags kVerifyFlags = kDefaultVerifyFlags>
83   ALWAYS_INLINE void SetWithoutChecksAndWriteBarrier(int32_t i, ObjPtr<T> object)
84       NO_THREAD_SAFETY_ANALYSIS;
85 
86   template<VerifyObjectFlags kVerifyFlags = kDefaultVerifyFlags,
87            ReadBarrierOption kReadBarrierOption = kWithReadBarrier>
88   ALWAYS_INLINE ObjPtr<T> GetWithoutChecks(int32_t i) REQUIRES_SHARED(Locks::mutator_lock_);
89 
90   // Copy src into this array (dealing with overlaps as memmove does) without assignability checks.
91   void AssignableMemmove(int32_t dst_pos,
92                          ObjPtr<ObjectArray<T>> src,
93                          int32_t src_pos,
94                          int32_t count)
95       REQUIRES_SHARED(Locks::mutator_lock_);
96 
97   // Copy src into this array assuming no overlap and without assignability checks.
98   void AssignableMemcpy(int32_t dst_pos,
99                         ObjPtr<ObjectArray<T>> src,
100                         int32_t src_pos,
101                         int32_t count)
102       REQUIRES_SHARED(Locks::mutator_lock_);
103 
104   // Copy src into this array with assignability checks.
105   template<bool kTransactionActive>
106   void AssignableCheckingMemcpy(int32_t dst_pos,
107                                 ObjPtr<ObjectArray<T>> src,
108                                 int32_t src_pos,
109                                 int32_t count,
110                                 bool throw_exception)
111       REQUIRES_SHARED(Locks::mutator_lock_);
112 
113   static ObjPtr<ObjectArray<T>> CopyOf(Handle<ObjectArray<T>> h_this,
114                                        Thread* self,
115                                        int32_t new_length)
116       REQUIRES_SHARED(Locks::mutator_lock_)
117       REQUIRES(!Roles::uninterruptible_);
118 
119   static MemberOffset OffsetOfElement(int32_t i);
120 
121   inline ConstObjPtrArrayIter<T> cbegin() const REQUIRES_SHARED(Locks::mutator_lock_);
122   inline ConstObjPtrArrayIter<T> cend() const REQUIRES_SHARED(Locks::mutator_lock_);
ConstIterate()123   inline IterationRange<ConstObjPtrArrayIter<T>> ConstIterate() const REQUIRES_SHARED(Locks::mutator_lock_) {
124     return IterationRange(cbegin(), cend());
125   }
126   inline ObjPtrArrayIter<T> begin() REQUIRES_SHARED(Locks::mutator_lock_);
127   inline ObjPtrArrayIter<T> end() REQUIRES_SHARED(Locks::mutator_lock_);
Iterate()128   inline IterationRange<ObjPtrArrayIter<T>> Iterate() REQUIRES_SHARED(Locks::mutator_lock_) {
129     return IterationRange(begin(), end());
130   }
131 
132   static inline ConstHandleArrayIter<T> cbegin(const Handle<ObjectArray<T>>& h_this)
133       REQUIRES_SHARED(Locks::mutator_lock_);
134   static inline ConstHandleArrayIter<T> cend(const Handle<ObjectArray<T>>& h_this)
135       REQUIRES_SHARED(Locks::mutator_lock_);
ConstIterate(const Handle<ObjectArray<T>> & h_this)136   static inline IterationRange<ConstHandleArrayIter<T>> ConstIterate(
137       const Handle<ObjectArray<T>>& h_this) REQUIRES_SHARED(Locks::mutator_lock_) {
138     return IterationRange(cbegin(h_this), cend(h_this));
139   }
140   static inline HandleArrayIter<T> begin(Handle<ObjectArray<T>>& h_this)
141       REQUIRES_SHARED(Locks::mutator_lock_);
142   static inline HandleArrayIter<T> end(Handle<ObjectArray<T>>& h_this)
143       REQUIRES_SHARED(Locks::mutator_lock_);
Iterate(Handle<ObjectArray<T>> & h_this)144   static inline IterationRange<HandleArrayIter<T>> Iterate(Handle<ObjectArray<T>>& h_this)
145       REQUIRES_SHARED(Locks::mutator_lock_) {
146     return IterationRange(begin(h_this), end(h_this));
147   }
148 
149  private:
150   // TODO fix thread safety analysis broken by the use of template. This should be
151   // REQUIRES_SHARED(Locks::mutator_lock_).
152   template<typename Visitor>
153   void VisitReferences(const Visitor& visitor) NO_THREAD_SAFETY_ANALYSIS;
154   template<typename Visitor>
155   void VisitReferences(const Visitor& visitor,
156                        MemberOffset begin,
157                        MemberOffset end) NO_THREAD_SAFETY_ANALYSIS;
158 
159   friend class Object;  // For VisitReferences
160   DISALLOW_IMPLICIT_CONSTRUCTORS(ObjectArray);
161 };
162 
163 // Everything is NO_THREAD_SAFETY_ANALYSIS to work-around STL incompat with thread-annotations.
164 // Everything should have REQUIRES_SHARED(Locks::mutator_lock_).
165 template <typename T, typename Container>
166 class ArrayIter {
167  private:
168   using Iter = ArrayIter<T, Container>;
169 
170  public:
171   using iterator_category = std::forward_iterator_tag;
172   using value_type = ObjPtr<T>;
173   using difference_type = ptrdiff_t;
174   using pointer = value_type*;
175   using reference = value_type&;
176 
ArrayIter(Container array,int32_t idx)177   ArrayIter(Container array, int32_t idx) NO_THREAD_SAFETY_ANALYSIS : array_(array), idx_(idx) {
178     CheckIdx();
179   }
180 
181   ArrayIter(const Iter& other) = default;  // NOLINT(runtime/explicit)
182   Iter& operator=(const Iter& other) = default;
183 
184   bool operator!=(const Iter& other) const NO_THREAD_SAFETY_ANALYSIS {
185     CheckIdx();
186     return !(*this == other);
187   }
188   bool operator==(const Iter& other) const NO_THREAD_SAFETY_ANALYSIS {
189     return Ptr(other.array_) == Ptr(array_) && other.idx_ == idx_;
190   }
191   Iter& operator++() NO_THREAD_SAFETY_ANALYSIS {
192     idx_++;
193     CheckIdx();
194     return *this;
195   }
196   Iter operator++(int) NO_THREAD_SAFETY_ANALYSIS {
197     Iter res(this);
198     idx_++;
199     CheckIdx();
200     return res;
201   }
202   ObjPtr<T> operator->() const NO_THREAD_SAFETY_ANALYSIS {
203     CheckIdx();
204     return array_->GetWithoutChecks(idx_);
205   }
206   ObjPtr<T> operator*() const NO_THREAD_SAFETY_ANALYSIS {
207     CheckIdx();
208     return array_->GetWithoutChecks(idx_);
209   }
210 
211  private:
212   // Checks current index and that locks are properly held.
213   void CheckIdx() const REQUIRES_SHARED(Locks::mutator_lock_);
214 
Ptr(const Handle<ObjectArray<T>> & p)215   static ObjectArray<T>* Ptr(const Handle<ObjectArray<T>>& p)
216       REQUIRES_SHARED(Locks::mutator_lock_) {
217     return p.Get();
218   }
Ptr(const ObjPtr<ObjectArray<T>> & p)219   static ObjectArray<T>* Ptr(const ObjPtr<ObjectArray<T>>& p)
220       REQUIRES_SHARED(Locks::mutator_lock_) {
221     return p.Ptr();
222   }
223 
224   Container array_;
225   int32_t idx_;
226 };
227 
228 }  // namespace mirror
229 }  // namespace art
230 
231 #endif  // ART_RUNTIME_MIRROR_OBJECT_ARRAY_H_
232