116 lines
2.6 KiB
C++
116 lines
2.6 KiB
C++
|
|
#ifndef REFPTR_H
|
|
#define REFPTR_H REFPTR_H
|
|
|
|
#include <stdlib.h> /* NULL */
|
|
#include <atomic> /* std::atomic */
|
|
|
|
template <typename T>
|
|
class refptr
|
|
{
|
|
public:
|
|
refptr();
|
|
refptr(T * ptr);
|
|
refptr(const refptr<T> & orig);
|
|
refptr & operator=(const refptr<T> & orig);
|
|
refptr & operator=(T * ptr);
|
|
~refptr();
|
|
T & operator*() const;
|
|
T * operator->() const;
|
|
bool isNull() const { return m_ptr == NULL; }
|
|
bool operator==(const refptr<T> & right) const;
|
|
bool operator!=(const refptr<T> & right) const;
|
|
|
|
private:
|
|
void cloneFrom(const refptr<T> & orig);
|
|
void destroy();
|
|
|
|
T * m_ptr;
|
|
/* reference count is atomic so that refptr copies may be made
|
|
* concurrently from multiple threads (e.g. the multithreaded
|
|
* renderer) without corrupting the count */
|
|
std::atomic<int> * m_refCount;
|
|
};
|
|
|
|
template <typename T> refptr<T>::refptr()
|
|
{
|
|
m_ptr = NULL;
|
|
m_refCount = NULL;
|
|
}
|
|
|
|
template <typename T> refptr<T>::refptr(T * ptr)
|
|
{
|
|
m_ptr = ptr;
|
|
m_refCount = new std::atomic<int>(1);
|
|
}
|
|
|
|
template <typename T> refptr<T>::refptr(const refptr<T> & orig)
|
|
{
|
|
cloneFrom(orig);
|
|
}
|
|
|
|
template <typename T> refptr<T> & refptr<T>::operator=(const refptr<T> & orig)
|
|
{
|
|
destroy();
|
|
cloneFrom(orig);
|
|
return *this;
|
|
}
|
|
|
|
template <typename T> refptr<T> & refptr<T>::operator=(T * ptr)
|
|
{
|
|
destroy();
|
|
m_ptr = ptr;
|
|
m_refCount = new std::atomic<int>(1);
|
|
return *this;
|
|
}
|
|
|
|
template <typename T> void refptr<T>::cloneFrom(const refptr<T> & orig)
|
|
{
|
|
this->m_ptr = orig.m_ptr;
|
|
this->m_refCount = orig.m_refCount;
|
|
if (m_refCount != NULL)
|
|
m_refCount->fetch_add(1, std::memory_order_relaxed);
|
|
}
|
|
|
|
template <typename T> refptr<T>::~refptr()
|
|
{
|
|
destroy();
|
|
}
|
|
|
|
template <typename T> void refptr<T>::destroy()
|
|
{
|
|
if (m_refCount != NULL)
|
|
{
|
|
/* fetch_sub returns the value prior to the decrement; if it was 1
|
|
* then this was the last reference and we own the cleanup */
|
|
if (m_refCount->fetch_sub(1, std::memory_order_acq_rel) == 1)
|
|
{
|
|
delete m_ptr;
|
|
delete m_refCount;
|
|
}
|
|
}
|
|
}
|
|
|
|
template <typename T> T & refptr<T>::operator*() const
|
|
{
|
|
return *m_ptr;
|
|
}
|
|
|
|
template <typename T> T * refptr<T>::operator->() const
|
|
{
|
|
return m_ptr;
|
|
}
|
|
|
|
template <typename T> bool refptr<T>::operator==(const refptr<T> & right) const
|
|
{
|
|
return m_ptr == right.m_ptr;
|
|
}
|
|
|
|
template <typename T> bool refptr<T>::operator!=(const refptr<T> & right) const
|
|
{
|
|
return m_ptr != right.m_ptr;
|
|
}
|
|
|
|
#endif
|
|
|