A base class for all things that want to be reference-counted. More...

#include "referenceCount.h"

Inheritance diagram for ReferenceCount:

Public Member Functions
int	get_ref_count () const

WeakReferenceList *	get_weak_list () const
	Returns the WeakReferenceList associated with this ReferenceCount object. More...

bool	has_weak_list () const
	Returns true if this particular ReferenceCount object has a WeakReferenceList created, false otherwise. More...

void	local_object ()
	This function should be called, once, immediately after creating a new instance of some ReferenceCount-derived object on the stack. More...

void	ref () const
	Explicitly increments the reference count. More...

bool	ref_if_nonzero () const
	Atomically increases the reference count of this object if it is not zero. More...

bool	test_ref_count_integrity () const
	Does some easy checks to make sure that the reference count isn't completely bogus. More...

bool	test_ref_count_nonzero () const
	Does some easy checks to make sure that the reference count isn't zero, or completely bogus. More...

virtual bool	unref () const
	Explicitly decrements the reference count. More...

WeakReferenceList *	weak_ref ()
	Adds the indicated PointerToVoid as a weak reference to this object. More...

void	weak_unref ()
	Removes the indicated PointerToVoid as a weak reference to this object. More...

Static Public Member Functions
static TypeHandle	get_class_type ()

static void	init_type ()

Public Attributes
	get_ref_count
	Returns the current reference count. More...

Detailed Description

A base class for all things that want to be reference-counted.

ReferenceCount works in conjunction with PointerTo to automatically delete objects when the last pointer to them goes away.

Definition at line 38 of file referenceCount.h.

Member Function Documentation

◆ get_weak_list()

WeakReferenceList * ReferenceCount::get_weak_list ( ) const

inline

Returns the WeakReferenceList associated with this ReferenceCount object.

If there has never been a WeakReferenceList associated with this object, creates one now.

The returned object will be deleted automatically when all weak and strong references to the object have gone.

Definition at line 257 of file referenceCount.I.

References AtomicAdjustDummyImpl::get_ptr().

◆ has_weak_list()

bool ReferenceCount::has_weak_list ( ) const

inline

Returns true if this particular ReferenceCount object has a WeakReferenceList created, false otherwise.

In general, this will be true if there was ever a WeakPointerTo created for this object (even if there is not any for it now).

Definition at line 244 of file referenceCount.I.

◆ local_object()

void ReferenceCount::local_object ( )

inline

This function should be called, once, immediately after creating a new instance of some ReferenceCount-derived object on the stack.

This allows the object to be passed to functions that will increment and decrement the object's reference count temporarily, and it will prevent the object from being deleted (inappropriately), when the reference count returns to zero. It actually achieves this by setting a large positive value in the reference count field.

Definition at line 229 of file referenceCount.I.

Referenced by AsyncTaskManager::find_task(), AsyncTaskManager::find_tasks(), and AsyncTaskManager::find_tasks_matching().

◆ ref()

void ReferenceCount::ref ( ) const

inline

Explicitly increments the reference count.

User code should avoid using ref() and unref() directly, which can result in missed reference counts. Instead, let a PointerTo object manage the reference counting automatically.

This function is const, even though it changes the object, because generally fiddling with an object's reference count isn't considered part of fiddling with the object. An object might be const in other ways, but we still need to accurately count the number of references to it.

Definition at line 151 of file referenceCount.I.

Referenced by CPT(), and PT().

◆ ref_if_nonzero()

bool ReferenceCount::ref_if_nonzero ( ) const

inline

Atomically increases the reference count of this object if it is not zero.

Do not use this. This exists only to implement a special case for weak pointers.

Returns: true if the reference count was incremented, false if it was zero.

Definition at line 306 of file referenceCount.I.

References AtomicAdjustDummyImpl::compare_and_exchange(), AtomicAdjustDummyImpl::get(), and test_ref_count_integrity().

◆ test_ref_count_integrity()

bool ReferenceCount::test_ref_count_integrity ( ) const

inline

Does some easy checks to make sure that the reference count isn't completely bogus.

Returns true if ok, false otherwise.

Definition at line 197 of file referenceCount.I.

Referenced by EggGroupNode::add_child(), InternalName::find_ancestor(), InternalName::get_ancestor(), InternalName::get_top(), ref_if_nonzero(), and split_vertex().

◆ test_ref_count_nonzero()

bool ReferenceCount::test_ref_count_nonzero ( ) const

inline

Does some easy checks to make sure that the reference count isn't zero, or completely bogus.

Returns true if ok, false otherwise.

Definition at line 210 of file referenceCount.I.

◆ unref()

bool ReferenceCount::unref ( ) const

inlinevirtual

Explicitly decrements the reference count.

Note that the object will not be implicitly deleted by unref() simply because the reference count drops to zero. (Having a member function delete itself is problematic.) However, see the helper function unref_delete().

User code should avoid using ref() and unref() directly, which can result in missed reference counts. Instead, let a PointerTo object manage the reference counting automatically.

This function is const, even though it changes the object, because generally fiddling with an object's reference count isn't considered part of fiddling with the object. An object might be const in other ways, but we still need to accurately count the number of references to it.

The return value is true if the new reference count is nonzero, false if it is zero.

Reimplemented in TransformState, RenderState, RenderEffects, RenderAttrib, GeomVertexArrayFormat, GeomVertexFormat, and InternalName.

Definition at line 179 of file referenceCount.I.

Referenced by RenderEffect::finalize(), Texture::finalize(), NodeReferenceCount::node_unref(), NodeCachedReferenceCount::node_unref(), InternalName::unref(), GeomVertexFormat::unref(), and GeomVertexArrayFormat::unref().

◆ weak_ref()

WeakReferenceList * ReferenceCount::weak_ref ( )

inline

Adds the indicated PointerToVoid as a weak reference to this object.

Returns an object that will persist as long as any reference (strong or weak) exists, for calling unref() or checking whether the object still exists.

Definition at line 271 of file referenceCount.I.

◆ weak_unref()

void ReferenceCount::weak_unref ( )

inline

Removes the indicated PointerToVoid as a weak reference to this object.

It must have previously been added via a call to weak_ref().

Definition at line 288 of file referenceCount.I.

Member Data Documentation

◆ get_ref_count

int ReferenceCount::get_ref_count

inline

Returns the current reference count.

Definition at line 53 of file referenceCount.h.

Referenced by RenderState::list_cycles().

The documentation for this class was generated from the following files:

panda/src/express/referenceCount.h
panda/src/express/referenceCount.cxx
panda/src/express/referenceCount.I

Public Member Functions

Static Public Member Functions

Public Attributes

Detailed Description

Member Function Documentation

◆ get_weak_list()

◆ has_weak_list()

◆ local_object()

◆ ref()

◆ ref_if_nonzero()

◆ test_ref_count_integrity()

◆ test_ref_count_nonzero()

◆ unref()

◆ weak_ref()

◆ weak_unref()

Member Data Documentation

◆ get_ref_count