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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_CORE_LIB_SUPPORT_REF_COUNTED_H
#define GRPC_CORE_LIB_SUPPORT_REF_COUNTED_H
#include <grpc/support/log.h>
#include <grpc/support/sync.h>
#include "src/core/lib/debug/trace.h"
#include "src/core/lib/support/debug_location.h"
#include "src/core/lib/support/memory.h"
namespace grpc_core {
// A base class for reference-counted objects.
// New objects should be created via New() and start with a refcount of 1.
// When the refcount reaches 0, the object will be deleted via Delete().
class RefCounted {
public:
void Ref() { gpr_ref(&refs_); }
void Unref() {
if (gpr_unref(&refs_)) {
Delete(this);
}
}
// Not copyable nor movable.
RefCounted(const RefCounted&) = delete;
RefCounted& operator=(const RefCounted&) = delete;
protected:
// Allow Delete() to access destructor.
template <typename T>
friend void Delete(T*);
RefCounted() { gpr_ref_init(&refs_, 1); }
virtual ~RefCounted() {}
private:
gpr_refcount refs_;
};
// An alternative version of the RefCounted base class that
// supports tracing. This is intended to be used in cases where the
// object will be handled both by idiomatic C++ code using smart
// pointers and legacy code that is manually calling Ref() and Unref().
// Once all of our code is converted to idiomatic C++, we may be able to
// eliminate this class.
class RefCountedWithTracing {
public:
void Ref() { gpr_ref(&refs_); }
void Ref(const DebugLocation& location, const char* reason) {
if (location.Log() && trace_flag_ != nullptr && trace_flag_->enabled()) {
gpr_atm old_refs = gpr_atm_no_barrier_load(&refs_.count);
gpr_log(GPR_DEBUG, "%s:%p %s:%d ref %" PRIdPTR " -> %" PRIdPTR " %s",
trace_flag_->name(), this, location.file(), location.line(),
old_refs, old_refs + 1, reason);
}
Ref();
}
void Unref() {
if (gpr_unref(&refs_)) {
Delete(this);
}
}
void Unref(const DebugLocation& location, const char* reason) {
if (location.Log() && trace_flag_ != nullptr && trace_flag_->enabled()) {
gpr_atm old_refs = gpr_atm_no_barrier_load(&refs_.count);
gpr_log(GPR_DEBUG, "%s:%p %s:%d unref %" PRIdPTR " -> %" PRIdPTR " %s",
trace_flag_->name(), this, location.file(), location.line(),
old_refs, old_refs - 1, reason);
}
Unref();
}
// Not copyable nor movable.
RefCountedWithTracing(const RefCountedWithTracing&) = delete;
RefCountedWithTracing& operator=(const RefCountedWithTracing&) = delete;
protected:
// Allow Delete() to access destructor.
template <typename T>
friend void Delete(T*);
RefCountedWithTracing() : RefCountedWithTracing(nullptr) {}
explicit RefCountedWithTracing(TraceFlag* trace_flag)
: trace_flag_(trace_flag) {
gpr_ref_init(&refs_, 1);
}
virtual ~RefCountedWithTracing() {}
private:
TraceFlag* trace_flag_ = nullptr;
gpr_refcount refs_;
};
} // namespace grpc_core
#endif /* GRPC_CORE_LIB_SUPPORT_REF_COUNTED_H */
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