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//
//
// 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_SRC_CORE_LIB_GPRPP_ORPHANABLE_H
#define GRPC_SRC_CORE_LIB_GPRPP_ORPHANABLE_H
#include <grpc/support/port_platform.h>
#include <cinttypes>
#include <memory>
#include <utility>
#include "src/core/lib/gprpp/debug_location.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() = 0;
// Not copyable or movable.
Orphanable(const Orphanable&) = delete;
Orphanable& operator=(const Orphanable&) = delete;
protected:
Orphanable() {}
virtual ~Orphanable() {}
};
class OrphanableDelete {
public:
template <typename T>
void operator()(T* p) {
p->Orphan();
}
};
template <typename T, typename Deleter = OrphanableDelete>
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, typename UnrefBehavior = UnrefDelete>
class InternallyRefCounted : public Orphanable {
public:
// Not copyable nor movable.
InternallyRefCounted(const InternallyRefCounted&) = delete;
InternallyRefCounted& operator=(const InternallyRefCounted&) = delete;
protected:
// Allow RefCountedPtr<> to access Unref() and IncrementRefCount().
template <typename T>
friend class RefCountedPtr;
// Note: Tracing is a no-op on non-debug builds.
explicit InternallyRefCounted(const char* trace = nullptr,
intptr_t initial_refcount = 1)
: refs_(initial_refcount, trace) {}
~InternallyRefCounted() override = 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 (GPR_UNLIKELY(refs_.Unref())) {
unref_behavior_(static_cast<Child*>(this));
}
}
void Unref(const DebugLocation& location, const char* reason) {
if (GPR_UNLIKELY(refs_.Unref(location, reason))) {
unref_behavior_(static_cast<Child*>(this));
}
}
private:
void IncrementRefCount() { refs_.Ref(); }
void IncrementRefCount(const DebugLocation& location, const char* reason) {
refs_.Ref(location, reason);
}
RefCount refs_;
GPR_NO_UNIQUE_ADDRESS UnrefBehavior unref_behavior_;
};
} // namespace grpc_core
#endif // GRPC_SRC_CORE_LIB_GPRPP_ORPHANABLE_H
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