Mathieu Chartier | eb8167a | 2014-05-07 15:43:14 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2014 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_HANDLE_H_ |
| 18 | #define ART_RUNTIME_HANDLE_H_ |
| 19 | |
| 20 | #include "base/casts.h" |
| 21 | #include "base/logging.h" |
| 22 | #include "base/macros.h" |
| 23 | #include "stack.h" |
| 24 | |
| 25 | namespace art { |
| 26 | |
| 27 | class Thread; |
| 28 | |
Mathieu Chartier | bfd9a43 | 2014-05-21 17:43:44 -0700 | [diff] [blame] | 29 | template<class T> class Handle; |
| 30 | |
Ian Rogers | 22d5e73 | 2014-07-15 22:23:51 -0700 | [diff] [blame^] | 31 | // Handles are memory locations that contain GC roots. As the mirror::Object*s within a handle are |
| 32 | // GC visible then the GC may move the references within them, something that couldn't be done with |
| 33 | // a wrap pointer. Handles are generally allocated within HandleScopes. ConstHandle is a super-class |
| 34 | // of Handle and doesn't support assignment operations. |
Mathieu Chartier | eb8167a | 2014-05-07 15:43:14 -0700 | [diff] [blame] | 35 | template<class T> |
Mathieu Chartier | bfd9a43 | 2014-05-21 17:43:44 -0700 | [diff] [blame] | 36 | class ConstHandle { |
Mathieu Chartier | eb8167a | 2014-05-07 15:43:14 -0700 | [diff] [blame] | 37 | public: |
Mathieu Chartier | bfd9a43 | 2014-05-21 17:43:44 -0700 | [diff] [blame] | 38 | ConstHandle() : reference_(nullptr) { |
Mathieu Chartier | eb8167a | 2014-05-07 15:43:14 -0700 | [diff] [blame] | 39 | } |
Ian Rogers | 22d5e73 | 2014-07-15 22:23:51 -0700 | [diff] [blame^] | 40 | |
| 41 | ALWAYS_INLINE ConstHandle(const ConstHandle<T>& handle) : reference_(handle.reference_) { |
Mathieu Chartier | eb8167a | 2014-05-07 15:43:14 -0700 | [diff] [blame] | 42 | } |
Ian Rogers | 22d5e73 | 2014-07-15 22:23:51 -0700 | [diff] [blame^] | 43 | |
| 44 | ALWAYS_INLINE ConstHandle<T>& operator=(const ConstHandle<T>& handle) { |
Mathieu Chartier | eb8167a | 2014-05-07 15:43:14 -0700 | [diff] [blame] | 45 | reference_ = handle.reference_; |
| 46 | return *this; |
| 47 | } |
Ian Rogers | 22d5e73 | 2014-07-15 22:23:51 -0700 | [diff] [blame^] | 48 | |
| 49 | ALWAYS_INLINE explicit ConstHandle(StackReference<T>* reference) : reference_(reference) { |
Mathieu Chartier | eb8167a | 2014-05-07 15:43:14 -0700 | [diff] [blame] | 50 | } |
Ian Rogers | 22d5e73 | 2014-07-15 22:23:51 -0700 | [diff] [blame^] | 51 | |
| 52 | ALWAYS_INLINE T& operator*() const SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { |
Mathieu Chartier | eb8167a | 2014-05-07 15:43:14 -0700 | [diff] [blame] | 53 | return *Get(); |
| 54 | } |
Ian Rogers | 22d5e73 | 2014-07-15 22:23:51 -0700 | [diff] [blame^] | 55 | |
| 56 | ALWAYS_INLINE T* operator->() const SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { |
Mathieu Chartier | eb8167a | 2014-05-07 15:43:14 -0700 | [diff] [blame] | 57 | return Get(); |
| 58 | } |
Ian Rogers | 22d5e73 | 2014-07-15 22:23:51 -0700 | [diff] [blame^] | 59 | |
| 60 | ALWAYS_INLINE T* Get() const SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { |
Mathieu Chartier | eb8167a | 2014-05-07 15:43:14 -0700 | [diff] [blame] | 61 | return reference_->AsMirrorPtr(); |
| 62 | } |
Ian Rogers | 22d5e73 | 2014-07-15 22:23:51 -0700 | [diff] [blame^] | 63 | |
| 64 | ALWAYS_INLINE jobject ToJObject() const SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { |
Mathieu Chartier | 0cd8135 | 2014-05-22 16:48:55 -0700 | [diff] [blame] | 65 | if (UNLIKELY(reference_->AsMirrorPtr() == nullptr)) { |
| 66 | // Special case so that we work with NullHandles. |
| 67 | return nullptr; |
| 68 | } |
Mathieu Chartier | eb8167a | 2014-05-07 15:43:14 -0700 | [diff] [blame] | 69 | return reinterpret_cast<jobject>(reference_); |
| 70 | } |
| 71 | |
Mathieu Chartier | 0cd8135 | 2014-05-22 16:48:55 -0700 | [diff] [blame] | 72 | protected: |
Mathieu Chartier | eb8167a | 2014-05-07 15:43:14 -0700 | [diff] [blame] | 73 | StackReference<T>* reference_; |
| 74 | |
| 75 | template<typename S> |
Mathieu Chartier | bfd9a43 | 2014-05-21 17:43:44 -0700 | [diff] [blame] | 76 | explicit ConstHandle(StackReference<S>* reference) |
Mathieu Chartier | eb8167a | 2014-05-07 15:43:14 -0700 | [diff] [blame] | 77 | : reference_(reinterpret_cast<StackReference<T>*>(reference)) { |
| 78 | } |
Mathieu Chartier | eb8167a | 2014-05-07 15:43:14 -0700 | [diff] [blame] | 79 | template<typename S> |
Mathieu Chartier | bfd9a43 | 2014-05-21 17:43:44 -0700 | [diff] [blame] | 80 | explicit ConstHandle(const ConstHandle<S>& handle) |
Mathieu Chartier | eb8167a | 2014-05-07 15:43:14 -0700 | [diff] [blame] | 81 | : reference_(reinterpret_cast<StackReference<T>*>(handle.reference_)) { |
| 82 | } |
| 83 | |
Mathieu Chartier | 0cd8135 | 2014-05-22 16:48:55 -0700 | [diff] [blame] | 84 | StackReference<T>* GetReference() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) ALWAYS_INLINE { |
| 85 | return reference_; |
| 86 | } |
Ian Rogers | 22d5e73 | 2014-07-15 22:23:51 -0700 | [diff] [blame^] | 87 | ALWAYS_INLINE const StackReference<T>* GetReference() const |
| 88 | SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { |
Mathieu Chartier | bfd9a43 | 2014-05-21 17:43:44 -0700 | [diff] [blame] | 89 | return reference_; |
| 90 | } |
| 91 | |
| 92 | private: |
| 93 | friend class BuildGenericJniFrameVisitor; |
| 94 | template<class S> friend class ConstHandle; |
| 95 | friend class HandleScope; |
| 96 | template<class S> friend class HandleWrapper; |
| 97 | template<size_t kNumReferences> friend class StackHandleScope; |
| 98 | }; |
| 99 | |
Ian Rogers | 22d5e73 | 2014-07-15 22:23:51 -0700 | [diff] [blame^] | 100 | // Handles that support assignment. |
Mathieu Chartier | bfd9a43 | 2014-05-21 17:43:44 -0700 | [diff] [blame] | 101 | template<class T> |
| 102 | class Handle : public ConstHandle<T> { |
| 103 | public: |
| 104 | Handle() { |
| 105 | } |
Ian Rogers | 22d5e73 | 2014-07-15 22:23:51 -0700 | [diff] [blame^] | 106 | |
| 107 | ALWAYS_INLINE Handle(const Handle<T>& handle) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) |
Mathieu Chartier | bfd9a43 | 2014-05-21 17:43:44 -0700 | [diff] [blame] | 108 | : ConstHandle<T>(handle.reference_) { |
| 109 | } |
Ian Rogers | 22d5e73 | 2014-07-15 22:23:51 -0700 | [diff] [blame^] | 110 | |
| 111 | ALWAYS_INLINE Handle<T>& operator=(const Handle<T>& handle) |
| 112 | SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { |
Mathieu Chartier | bfd9a43 | 2014-05-21 17:43:44 -0700 | [diff] [blame] | 113 | ConstHandle<T>::operator=(handle); |
| 114 | return *this; |
| 115 | } |
Ian Rogers | 22d5e73 | 2014-07-15 22:23:51 -0700 | [diff] [blame^] | 116 | |
| 117 | ALWAYS_INLINE explicit Handle(StackReference<T>* reference) |
| 118 | SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) |
| 119 | : ConstHandle<T>(reference) { |
Mathieu Chartier | bfd9a43 | 2014-05-21 17:43:44 -0700 | [diff] [blame] | 120 | } |
Ian Rogers | 22d5e73 | 2014-07-15 22:23:51 -0700 | [diff] [blame^] | 121 | |
| 122 | ALWAYS_INLINE T* Assign(T* reference) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { |
Mathieu Chartier | bfd9a43 | 2014-05-21 17:43:44 -0700 | [diff] [blame] | 123 | StackReference<T>* ref = ConstHandle<T>::GetReference(); |
| 124 | T* const old = ref->AsMirrorPtr(); |
| 125 | ref->Assign(reference); |
| 126 | return old; |
| 127 | } |
| 128 | |
Ian Rogers | 22d5e73 | 2014-07-15 22:23:51 -0700 | [diff] [blame^] | 129 | template<typename S> |
| 130 | explicit Handle(const Handle<S>& handle) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) |
| 131 | : ConstHandle<T>(handle) { |
| 132 | } |
| 133 | |
Mathieu Chartier | bfd9a43 | 2014-05-21 17:43:44 -0700 | [diff] [blame] | 134 | protected: |
| 135 | template<typename S> |
| 136 | explicit Handle(StackReference<S>* reference) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) |
| 137 | : ConstHandle<T>(reference) { |
| 138 | } |
Mathieu Chartier | 0cd8135 | 2014-05-22 16:48:55 -0700 | [diff] [blame] | 139 | |
| 140 | private: |
| 141 | friend class BuildGenericJniFrameVisitor; |
Mathieu Chartier | eb8167a | 2014-05-07 15:43:14 -0700 | [diff] [blame] | 142 | friend class HandleScope; |
| 143 | template<class S> friend class HandleWrapper; |
| 144 | template<size_t kNumReferences> friend class StackHandleScope; |
| 145 | }; |
| 146 | |
Ian Rogers | 22d5e73 | 2014-07-15 22:23:51 -0700 | [diff] [blame^] | 147 | // A special case of Handle that only holds references to null. |
Mathieu Chartier | 0cd8135 | 2014-05-22 16:48:55 -0700 | [diff] [blame] | 148 | template<class T> |
| 149 | class NullHandle : public Handle<T> { |
| 150 | public: |
| 151 | NullHandle() : Handle<T>(&null_ref_) { |
| 152 | } |
| 153 | |
| 154 | private: |
| 155 | StackReference<T> null_ref_; |
| 156 | }; |
| 157 | |
Mathieu Chartier | eb8167a | 2014-05-07 15:43:14 -0700 | [diff] [blame] | 158 | } // namespace art |
| 159 | |
| 160 | #endif // ART_RUNTIME_HANDLE_H_ |