diff --git a/src/core/lib/gprpp/orphanable.h b/src/core/lib/gprpp/orphanable.h index d0ec9b6461d..3123e3f5a39 100644 --- a/src/core/lib/gprpp/orphanable.h +++ b/src/core/lib/gprpp/orphanable.h @@ -86,7 +86,8 @@ class InternallyRefCounted : public Orphanable { GPRC_ALLOW_CLASS_TO_USE_NON_PUBLIC_DELETE // Allow RefCountedPtr<> to access Unref() and IncrementRefCount(). - friend class RefCountedPtr; + template + friend class RefCountedPtr; InternallyRefCounted() { gpr_ref_init(&refs_, 1); } virtual ~InternallyRefCounted() {} @@ -129,7 +130,8 @@ class InternallyRefCountedWithTracing : public Orphanable { GPRC_ALLOW_CLASS_TO_USE_NON_PUBLIC_DELETE // Allow RefCountedPtr<> to access Unref() and IncrementRefCount(). - friend class RefCountedPtr; + template + friend class RefCountedPtr; InternallyRefCountedWithTracing() : InternallyRefCountedWithTracing(static_cast(nullptr)) {} diff --git a/src/core/lib/gprpp/ref_counted.h b/src/core/lib/gprpp/ref_counted.h index ddac5bd4755..03c293f6ed9 100644 --- a/src/core/lib/gprpp/ref_counted.h +++ b/src/core/lib/gprpp/ref_counted.h @@ -73,7 +73,8 @@ class RefCounted { private: // Allow RefCountedPtr<> to access IncrementRefCount(). - friend class RefCountedPtr; + template + friend class RefCountedPtr; void IncrementRefCount() { gpr_ref(&refs_); } @@ -152,7 +153,8 @@ class RefCountedWithTracing { private: // Allow RefCountedPtr<> to access IncrementRefCount(). - friend class RefCountedPtr; + template + friend class RefCountedPtr; void IncrementRefCount() { gpr_ref(&refs_); } diff --git a/src/core/lib/gprpp/ref_counted_ptr.h b/src/core/lib/gprpp/ref_counted_ptr.h index 534d3d03cb4..8a6615a7799 100644 --- a/src/core/lib/gprpp/ref_counted_ptr.h +++ b/src/core/lib/gprpp/ref_counted_ptr.h @@ -36,7 +36,8 @@ class RefCountedPtr { RefCountedPtr(std::nullptr_t) {} // If value is non-null, we take ownership of a ref to it. - explicit RefCountedPtr(T* value) { value_ = value; } + template + explicit RefCountedPtr(Y* value) { value_ = value; } // Move support. RefCountedPtr(RefCountedPtr&& other) { @@ -49,6 +50,18 @@ class RefCountedPtr { other.value_ = nullptr; return *this; } + template + RefCountedPtr(RefCountedPtr&& other) { + value_ = other.value_; + other.value_ = nullptr; + } + template + RefCountedPtr& operator=(RefCountedPtr&& other) { + if (value_ != nullptr) value_->Unref(); + value_ = other.value_; + other.value_ = nullptr; + return *this; + } // Copy support. RefCountedPtr(const RefCountedPtr& other) { @@ -63,17 +76,37 @@ class RefCountedPtr { value_ = other.value_; return *this; } + template + RefCountedPtr(const RefCountedPtr& other) { + if (other.value_ != nullptr) other.value_->IncrementRefCount(); + value_ = other.value_; + } + template + 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(); + if (value_ != nullptr) value_->Unref(); + value_ = 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) { + template + void reset(Y* value) { if (value_ != nullptr) value_->Unref(); value_ = value; } + void reset() { + if (value_ != nullptr) value_->Unref(); + value_ = nullptr; + } + // 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 @@ -89,16 +122,30 @@ class RefCountedPtr { T& operator*() const { return *value_; } T* operator->() const { return value_; } - bool operator==(const RefCountedPtr& other) const { + template + bool operator==(const RefCountedPtr& other) const { return value_ == other.value_; } - bool operator==(const T* other) const { return value_ == other; } - bool operator!=(const RefCountedPtr& other) const { + + template + bool operator==(const Y* other) const { return value_ == other; } + + bool operator==(std::nullptr_t) const { return value_ == nullptr; } + + template + bool operator!=(const RefCountedPtr& other) const { return value_ != other.value_; } - bool operator!=(const T* other) const { return value_ != other; } + + template + bool operator!=(const Y* other) const { return value_ != other; } + + bool operator!=(std::nullptr_t) const { return value_ != nullptr; } private: + template + friend class RefCountedPtr; + T* value_ = nullptr; }; diff --git a/test/core/gprpp/ref_counted_ptr_test.cc b/test/core/gprpp/ref_counted_ptr_test.cc index aa30b72282f..6df6e348c6f 100644 --- a/test/core/gprpp/ref_counted_ptr_test.cc +++ b/test/core/gprpp/ref_counted_ptr_test.cc @@ -127,7 +127,7 @@ TEST(RefCountedPtr, ResetFromNonNullToNull) { TEST(RefCountedPtr, ResetFromNullToNull) { RefCountedPtr foo; EXPECT_EQ(nullptr, foo.get()); - foo.reset(nullptr); + foo.reset(); EXPECT_EQ(nullptr, foo.get()); } @@ -175,6 +175,30 @@ TEST(RefCountedPtr, RefCountedWithTracing) { foo->Unref(DEBUG_LOCATION, "foo"); } +class Parent : public RefCounted { + public: + Parent() {} +}; + +class Child : public Parent { + public: + Child() {} +}; + +void FunctionTakingParent(RefCountedPtr o) {} + +void FunctionTakingChild(RefCountedPtr o) {} + +TEST(RefCountedPtr, CanPassChildToFunctionExpectingParent) { + RefCountedPtr child = MakeRefCounted(); + FunctionTakingParent(child); +} + +TEST(RefCountedPtr, CanPassChildToFunctionExpectingChild) { + RefCountedPtr child = MakeRefCounted(); + FunctionTakingChild(child); +} + } // namespace } // namespace testing } // namespace grpc_core