Fix existing ref counting classes and add new ones.
diff --git a/src/core/lib/support/orphanable.h b/src/core/lib/support/orphanable.h
new file mode 100644
index 0000000..63eda2e
--- /dev/null
+++ b/src/core/lib/support/orphanable.h
@@ -0,0 +1,166 @@
+/*
+ *
+ * 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_ORPHANABLE_H
+#define GRPC_CORE_LIB_SUPPORT_ORPHANABLE_H
+
+#include <grpc/support/log.h>
+#include <grpc/support/sync.h>
+
+#include <memory>
+
+#include "src/core/lib/debug/trace.h"
+#include "src/core/lib/support/abstract.h"
+#include "src/core/lib/support/debug_location.h"
+#include "src/core/lib/support/memory.h"
+
+namespace grpc_core {
+
+// A base class for orphanable objects.
+class Orphanable {
+ public:
+ // Gives up ownership of the object. The implementation must arrange
+ // to 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.
+class InternallyRefCounted : public Orphanable {
+ public:
+ // Not copyable nor movable.
+ InternallyRefCounted(const InternallyRefCounted&) = delete;
+ InternallyRefCounted& operator=(const InternallyRefCounted&) = delete;
+
+ GRPC_ABSTRACT_BASE_CLASS
+
+ protected:
+ InternallyRefCounted() { gpr_ref_init(&refs_, 1); }
+ virtual ~InternallyRefCounted() {}
+
+ void Ref() { gpr_ref(&refs_); }
+
+ void Unref() {
+ if (gpr_unref(&refs_)) {
+ Delete(this);
+ }
+ }
+
+ // Allow Delete() to access destructor.
+ template <typename T>
+ friend void Delete(T*);
+
+ private:
+ gpr_refcount refs_;
+};
+
+// An alternative version of the InternallyRefCounted 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 InternallyRefCountedWithTracing : public Orphanable {
+ public:
+ // Not copyable nor movable.
+ InternallyRefCountedWithTracing(const InternallyRefCountedWithTracing&) =
+ delete;
+ InternallyRefCountedWithTracing& operator=(
+ const InternallyRefCountedWithTracing&) = delete;
+
+ GRPC_ABSTRACT_BASE_CLASS
+
+ protected:
+ // Allow Delete() to access destructor.
+ template <typename T>
+ friend void Delete(T*);
+
+ InternallyRefCountedWithTracing()
+ : InternallyRefCountedWithTracing(static_cast<TraceFlag*>(nullptr)) {}
+
+ explicit InternallyRefCountedWithTracing(TraceFlag* trace_flag)
+ : trace_flag_(trace_flag) {
+ gpr_ref_init(&refs_, 1);
+ }
+
+#ifdef NDEBUG
+ explicit InternallyRefCountedWithTracing(DebugOnlyTraceFlag* trace_flag)
+ : InternallyRefCountedWithTracing() {}
+#endif
+
+ virtual ~InternallyRefCountedWithTracing() {}
+
+ 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();
+ }
+
+ private:
+ TraceFlag* trace_flag_ = nullptr;
+ gpr_refcount refs_;
+};
+
+} // namespace grpc_core
+
+#endif /* GRPC_CORE_LIB_SUPPORT_ORPHANABLE_H */