| /* |
| * |
| * Copyright 2017 gRPC authors. |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| * |
| */ |
| |
| #ifndef GRPC_CORE_LIB_GPRPP_REF_COUNTED_PTR_H |
| #define GRPC_CORE_LIB_GPRPP_REF_COUNTED_PTR_H |
| |
| #include <grpc/support/port_platform.h> |
| |
| #include <type_traits> |
| #include <utility> |
| |
| #include "src/core/lib/gprpp/debug_location.h" |
| #include "src/core/lib/gprpp/memory.h" |
| |
| namespace grpc_core { |
| |
| // A smart pointer class for objects that provide IncrementRefCount() and |
| // Unref() methods, such as those provided by the RefCounted base class. |
| template <typename T> |
| class RefCountedPtr { |
| public: |
| RefCountedPtr() {} |
| RefCountedPtr(std::nullptr_t) {} |
| |
| // If value is non-null, we take ownership of a ref to it. |
| template <typename Y> |
| explicit RefCountedPtr(Y* value) { |
| value_ = value; |
| } |
| |
| // Move ctors. |
| RefCountedPtr(RefCountedPtr&& other) { |
| value_ = other.value_; |
| other.value_ = nullptr; |
| } |
| template <typename Y> |
| RefCountedPtr(RefCountedPtr<Y>&& other) { |
| value_ = static_cast<T*>(other.value_); |
| other.value_ = nullptr; |
| } |
| |
| // Move assignment. |
| RefCountedPtr& operator=(RefCountedPtr&& other) { |
| reset(other.value_); |
| other.value_ = nullptr; |
| return *this; |
| } |
| template <typename Y> |
| RefCountedPtr& operator=(RefCountedPtr<Y>&& other) { |
| reset(other.value_); |
| other.value_ = nullptr; |
| return *this; |
| } |
| |
| // Copy ctors. |
| RefCountedPtr(const RefCountedPtr& other) { |
| if (other.value_ != nullptr) other.value_->IncrementRefCount(); |
| value_ = other.value_; |
| } |
| template <typename Y> |
| RefCountedPtr(const RefCountedPtr<Y>& other) { |
| static_assert(std::has_virtual_destructor<T>::value, |
| "T does not have a virtual dtor"); |
| if (other.value_ != nullptr) other.value_->IncrementRefCount(); |
| value_ = static_cast<T*>(other.value_); |
| } |
| |
| // Copy assignment. |
| RefCountedPtr& operator=(const RefCountedPtr& other) { |
| // Note: Order of reffing and unreffing is important here in case value_ |
| // and other.value_ are the same object. |
| if (other.value_ != nullptr) other.value_->IncrementRefCount(); |
| reset(other.value_); |
| return *this; |
| } |
| template <typename Y> |
| RefCountedPtr& operator=(const RefCountedPtr<Y>& other) { |
| static_assert(std::has_virtual_destructor<T>::value, |
| "T does not have a virtual dtor"); |
| // Note: Order of reffing and unreffing is important here in case value_ |
| // and other.value_ are the same object. |
| if (other.value_ != nullptr) other.value_->IncrementRefCount(); |
| reset(other.value_); |
| return *this; |
| } |
| |
| ~RefCountedPtr() { |
| if (value_ != nullptr) value_->Unref(); |
| } |
| |
| // If value is non-null, we take ownership of a ref to it. |
| void reset(T* value = nullptr) { |
| if (value_ != nullptr) value_->Unref(); |
| value_ = value; |
| } |
| void reset(const DebugLocation& location, const char* reason, |
| T* value = nullptr) { |
| if (value_ != nullptr) value_->Unref(location, reason); |
| value_ = value; |
| } |
| template <typename Y> |
| void reset(Y* value = nullptr) { |
| static_assert(std::has_virtual_destructor<T>::value, |
| "T does not have a virtual dtor"); |
| if (value_ != nullptr) value_->Unref(); |
| value_ = static_cast<T*>(value); |
| } |
| template <typename Y> |
| void reset(const DebugLocation& location, const char* reason, |
| Y* value = nullptr) { |
| static_assert(std::has_virtual_destructor<T>::value, |
| "T does not have a virtual dtor"); |
| if (value_ != nullptr) value_->Unref(location, reason); |
| value_ = static_cast<T*>(value); |
| } |
| |
| // TODO(roth): This method exists solely as a transition mechanism to allow |
| // us to pass a ref to idiomatic C code that does not use RefCountedPtr<>. |
| // Once all of our code has been converted to idiomatic C++, this |
| // method should go away. |
| T* release() { |
| T* value = value_; |
| value_ = nullptr; |
| return value; |
| } |
| |
| T* get() const { return value_; } |
| |
| T& operator*() const { return *value_; } |
| T* operator->() const { return value_; } |
| |
| template <typename Y> |
| bool operator==(const RefCountedPtr<Y>& other) const { |
| return value_ == other.value_; |
| } |
| |
| template <typename Y> |
| bool operator==(const Y* other) const { |
| return value_ == other; |
| } |
| |
| bool operator==(std::nullptr_t) const { return value_ == nullptr; } |
| |
| template <typename Y> |
| bool operator!=(const RefCountedPtr<Y>& other) const { |
| return value_ != other.value_; |
| } |
| |
| template <typename Y> |
| bool operator!=(const Y* other) const { |
| return value_ != other; |
| } |
| |
| bool operator!=(std::nullptr_t) const { return value_ != nullptr; } |
| |
| private: |
| template <typename Y> |
| friend class RefCountedPtr; |
| |
| T* value_ = nullptr; |
| }; |
| |
| template <typename T, typename... Args> |
| inline RefCountedPtr<T> MakeRefCounted(Args&&... args) { |
| return RefCountedPtr<T>(New<T>(std::forward<Args>(args)...)); |
| } |
| |
| } // namespace grpc_core |
| |
| #endif /* GRPC_CORE_LIB_GPRPP_REF_COUNTED_PTR_H */ |