godot/thirdparty/thekla_atlas/nvcore/RefCounted.h
Hein-Pieter van Braam bf05309af7 Import thekla_atlas
As requested by reduz, an import of thekla_atlas into thirdparty/
2017-12-08 15:47:15 +01:00

150 lines
3.1 KiB
C++

// This code is in the public domain -- Ignacio Castaño <castano@gmail.com>
#ifndef NV_CORE_REFCOUNTED_H
#define NV_CORE_REFCOUNTED_H
#include "nvcore.h"
#include "Debug.h"
#define NV_DECLARE_PTR(Class) \
template <class T> class SmartPtr; \
typedef SmartPtr<class Class> Class ## Ptr; \
typedef SmartPtr<const class Class> Class ## ConstPtr
namespace nv
{
/// Weak proxy.
class WeakProxy
{
NV_FORBID_COPY(WeakProxy);
public:
/// Ctor.
WeakProxy(void * ptr) : m_count(0), m_ptr(ptr) { }
/// Dtor.
~WeakProxy()
{
nvCheck( m_count == 0 );
}
/// Increase reference count.
uint addRef() const
{
m_count++;
return m_count;
}
/// Decrease reference count and remove when 0.
uint release() const
{
nvCheck( m_count > 0 );
m_count--;
if( m_count == 0 ) {
delete this;
return 0;
}
return m_count;
}
/// WeakPtr's call this to determine if their pointer is valid or not.
bool isAlive() const {
return m_ptr != NULL;
}
/// Only the actual object should call this.
void notifyObjectDied() {
m_ptr = NULL;
}
/// Return proxy pointer.
void * ptr() const {
return m_ptr;
}
private:
mutable int m_count;
void * m_ptr;
};
/// Reference counted base class to be used with SmartPtr and WeakPtr.
class RefCounted
{
NV_FORBID_COPY(RefCounted);
public:
/// Ctor.
RefCounted() : m_count(0), m_weak_proxy(NULL)
{
}
/// Virtual dtor.
virtual ~RefCounted()
{
nvCheck( m_count == 0 );
releaseWeakProxy();
}
/// Increase reference count.
uint addRef() const
{
m_count++;
return m_count;
}
/// Decrease reference count and remove when 0.
uint release() const
{
nvCheck( m_count > 0 );
m_count--;
if( m_count == 0 ) {
delete this;
return 0;
}
return m_count;
}
/// Get weak proxy.
WeakProxy * getWeakProxy() const
{
if (m_weak_proxy == NULL) {
m_weak_proxy = new WeakProxy((void *)this);
m_weak_proxy->addRef();
}
return m_weak_proxy;
}
/// Release the weak proxy.
void releaseWeakProxy() const
{
if (m_weak_proxy != NULL) {
m_weak_proxy->notifyObjectDied();
m_weak_proxy->release();
m_weak_proxy = NULL;
}
}
/// Get reference count.
int refCount() const
{
return m_count;
}
private:
mutable int m_count;
mutable WeakProxy * m_weak_proxy;
};
} // nv namespace
#endif // NV_CORE_REFCOUNTED_H