227a4eae77
The ImplicitSharingPtr has an implicit constructor for raw pointers. This has unintended effects when comparing an ImplicitSharingPtr to a raw pointer: The raw pointer is implicitly converted to the shared pointer (without change in refcount) and when going out of scope will decrement user count, eventually freeing the data. Conversion from raw pointer to shared pointer should not happen implicitly. The constructor is made explicit now. This requires a little more boilerplate when constructing a sharing pointer. A special constructor for the nullptr is added so comparison with nullptr can still happen without writing out a constructor. Pull Request: https://projects.blender.org/blender/blender/pulls/115476
153 lines
2.6 KiB
C++
153 lines
2.6 KiB
C++
/* SPDX-FileCopyrightText: 2023 Blender Authors
|
|
*
|
|
* SPDX-License-Identifier: GPL-2.0-or-later */
|
|
|
|
#pragma once
|
|
|
|
/** \file
|
|
* \ingroup bli
|
|
*/
|
|
|
|
#include "BLI_implicit_sharing.hh"
|
|
#include "BLI_struct_equality_utils.hh"
|
|
|
|
namespace blender {
|
|
|
|
/**
|
|
* #ImplicitSharingPtr is a smart pointer that manages implicit sharing. It's designed to work with
|
|
* types that derive from #ImplicitSharingMixin. It is fairly similar to #std::shared_ptr but
|
|
* requires the reference count to be embedded in the data.
|
|
*/
|
|
template<typename T> class ImplicitSharingPtr {
|
|
private:
|
|
T *data_ = nullptr;
|
|
|
|
public:
|
|
ImplicitSharingPtr() = default;
|
|
|
|
explicit ImplicitSharingPtr(T *data) : data_(data) {}
|
|
|
|
/* Implicit conversion from nullptr. */
|
|
ImplicitSharingPtr(std::nullptr_t) : data_(nullptr) {}
|
|
|
|
ImplicitSharingPtr(const ImplicitSharingPtr &other) : data_(other.data_)
|
|
{
|
|
this->add_user(data_);
|
|
}
|
|
|
|
ImplicitSharingPtr(ImplicitSharingPtr &&other) : data_(other.data_)
|
|
{
|
|
other.data_ = nullptr;
|
|
}
|
|
|
|
~ImplicitSharingPtr()
|
|
{
|
|
this->remove_user_and_delete_if_last(data_);
|
|
}
|
|
|
|
ImplicitSharingPtr &operator=(const ImplicitSharingPtr &other)
|
|
{
|
|
if (this == &other) {
|
|
return *this;
|
|
}
|
|
|
|
this->remove_user_and_delete_if_last(data_);
|
|
data_ = other.data_;
|
|
this->add_user(data_);
|
|
return *this;
|
|
}
|
|
|
|
ImplicitSharingPtr &operator=(ImplicitSharingPtr &&other)
|
|
{
|
|
if (this == &other) {
|
|
return *this;
|
|
}
|
|
|
|
this->remove_user_and_delete_if_last(data_);
|
|
data_ = other.data_;
|
|
other.data_ = nullptr;
|
|
return *this;
|
|
}
|
|
|
|
T *operator->()
|
|
{
|
|
BLI_assert(data_ != nullptr);
|
|
return data_;
|
|
}
|
|
|
|
const T *operator->() const
|
|
{
|
|
BLI_assert(data_ != nullptr);
|
|
return data_;
|
|
}
|
|
|
|
T &operator*()
|
|
{
|
|
BLI_assert(data_ != nullptr);
|
|
return *data_;
|
|
}
|
|
|
|
const T &operator*() const
|
|
{
|
|
BLI_assert(data_ != nullptr);
|
|
return *data_;
|
|
}
|
|
|
|
operator bool() const
|
|
{
|
|
return data_ != nullptr;
|
|
}
|
|
|
|
T *get()
|
|
{
|
|
return data_;
|
|
}
|
|
|
|
const T *get() const
|
|
{
|
|
return data_;
|
|
}
|
|
|
|
T *release()
|
|
{
|
|
T *data = data_;
|
|
data_ = nullptr;
|
|
return data;
|
|
}
|
|
|
|
void reset()
|
|
{
|
|
this->remove_user_and_delete_if_last(data_);
|
|
data_ = nullptr;
|
|
}
|
|
|
|
bool has_value() const
|
|
{
|
|
return data_ != nullptr;
|
|
}
|
|
|
|
uint64_t hash() const
|
|
{
|
|
return get_default_hash(data_);
|
|
}
|
|
|
|
BLI_STRUCT_EQUALITY_OPERATORS_1(ImplicitSharingPtr, data_)
|
|
|
|
private:
|
|
static void add_user(T *data)
|
|
{
|
|
if (data != nullptr) {
|
|
data->add_user();
|
|
}
|
|
}
|
|
|
|
static void remove_user_and_delete_if_last(T *data)
|
|
{
|
|
if (data != nullptr) {
|
|
data->remove_user_and_delete_if_last();
|
|
}
|
|
}
|
|
};
|
|
|
|
} // namespace blender
|