| /* |
| * |
| * 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_ORPHANABLE_H |
| #define GRPC_CORE_LIB_GPRPP_ORPHANABLE_H |
| |
| #include <grpc/support/port_platform.h> |
| |
| #include <grpc/support/log.h> |
| #include <grpc/support/sync.h> |
| |
| #include <cinttypes> |
| #include <memory> |
| |
| #include "src/core/lib/debug/trace.h" |
| #include "src/core/lib/gprpp/abstract.h" |
| #include "src/core/lib/gprpp/debug_location.h" |
| #include "src/core/lib/gprpp/memory.h" |
| #include "src/core/lib/gprpp/ref_counted.h" |
| #include "src/core/lib/gprpp/ref_counted_ptr.h" |
| |
| namespace grpc_core { |
| |
| // A base class for orphanable objects, which have one external owner |
| // but are not necessarily destroyed immediately when the external owner |
| // gives up ownership. Instead, the owner calls the object's Orphan() |
| // method, and the object then takes responsibility for its own cleanup |
| // and destruction. |
| class Orphanable { |
| public: |
| // Gives up ownership of the object. The implementation must arrange |
| // to eventually destroy the object without further interaction from the |
| // caller. |
| virtual void Orphan() GRPC_ABSTRACT; |
| |
| // Not copyable or movable. |
| Orphanable(const Orphanable&) = delete; |
| Orphanable& operator=(const Orphanable&) = delete; |
| |
| GRPC_ABSTRACT_BASE_CLASS |
| |
| protected: |
| Orphanable() {} |
| virtual ~Orphanable() {} |
| }; |
| |
| template <typename T> |
| class OrphanableDelete { |
| public: |
| void operator()(T* p) { p->Orphan(); } |
| }; |
| |
| template <typename T, typename Deleter = OrphanableDelete<T>> |
| using OrphanablePtr = std::unique_ptr<T, Deleter>; |
| |
| template <typename T, typename... Args> |
| inline OrphanablePtr<T> MakeOrphanable(Args&&... args) { |
| return OrphanablePtr<T>(New<T>(std::forward<Args>(args)...)); |
| } |
| |
| // A type of Orphanable with internal ref-counting. |
| template <typename Child> |
| class InternallyRefCounted : public Orphanable { |
| public: |
| // Not copyable nor movable. |
| InternallyRefCounted(const InternallyRefCounted&) = delete; |
| InternallyRefCounted& operator=(const InternallyRefCounted&) = delete; |
| |
| GRPC_ABSTRACT_BASE_CLASS |
| |
| protected: |
| GPRC_ALLOW_CLASS_TO_USE_NON_PUBLIC_DELETE |
| |
| // Allow RefCountedPtr<> to access Unref() and IncrementRefCount(). |
| template <typename T> |
| friend class RefCountedPtr; |
| |
| // TraceFlagT is defined to accept both DebugOnlyTraceFlag and TraceFlag. |
| // Note: RefCount tracing is only enabled on debug builds, even when a |
| // TraceFlag is used. |
| template <typename TraceFlagT = TraceFlag> |
| explicit InternallyRefCounted(TraceFlagT* trace_flag = nullptr) |
| : refs_(1, trace_flag) {} |
| virtual ~InternallyRefCounted() = default; |
| |
| RefCountedPtr<Child> Ref() GRPC_MUST_USE_RESULT { |
| IncrementRefCount(); |
| return RefCountedPtr<Child>(static_cast<Child*>(this)); |
| } |
| RefCountedPtr<Child> Ref(const DebugLocation& location, |
| const char* reason) GRPC_MUST_USE_RESULT { |
| IncrementRefCount(location, reason); |
| return RefCountedPtr<Child>(static_cast<Child*>(this)); |
| } |
| |
| void Unref() { |
| if (refs_.Unref()) { |
| Delete(static_cast<Child*>(this)); |
| } |
| } |
| void Unref(const DebugLocation& location, const char* reason) { |
| if (refs_.Unref(location, reason)) { |
| Delete(static_cast<Child*>(this)); |
| } |
| } |
| |
| private: |
| void IncrementRefCount() { refs_.Ref(); } |
| void IncrementRefCount(const DebugLocation& location, const char* reason) { |
| refs_.Ref(location, reason); |
| } |
| |
| grpc_core::RefCount refs_; |
| }; |
| |
| } // namespace grpc_core |
| |
| #endif /* GRPC_CORE_LIB_GPRPP_ORPHANABLE_H */ |