gc_root.h revision 94f7b49578b6aaa80de8ffed230648d601393905
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_GC_ROOT_H_ 18#define ART_RUNTIME_GC_ROOT_H_ 19 20#include "base/mutex.h" // For Locks::mutator_lock_. 21#include "object_callbacks.h" 22 23namespace art { 24 25template<class MirrorType> 26class GcRoot { 27 public: 28 template<ReadBarrierOption kReadBarrierOption = kWithReadBarrier> 29 ALWAYS_INLINE MirrorType* Read() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 30 31 void VisitRoot(RootCallback* callback, void* arg, uint32_t thread_id, RootType root_type) { 32 callback(reinterpret_cast<mirror::Object**>(&root_), arg, thread_id, root_type); 33 } 34 35 // This is only used by IrtIterator. 36 ALWAYS_INLINE MirrorType** AddressWithoutBarrier() { 37 return &root_; 38 } 39 40 bool IsNull() const { 41 // It's safe to null-check it without a read barrier. 42 return root_ == nullptr; 43 } 44 45 ALWAYS_INLINE explicit GcRoot<MirrorType>() : root_(nullptr) { 46 } 47 48 ALWAYS_INLINE explicit GcRoot<MirrorType>(MirrorType* ref) 49 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) : root_(ref) { 50 } 51 52 private: 53 MirrorType* root_; 54}; 55 56} // namespace art 57 58#endif // ART_RUNTIME_GC_ROOT_H_ 59