open_toontown_panda3d/panda/src/putil/nodeCachedReferenceCount.I

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// Filename: nodeCachedReferenceCount.I
// Created by: drose (07May05)
//
////////////////////////////////////////////////////////////////////
//
// PANDA 3D SOFTWARE
// Copyright (c) 2001 - 2004, Disney Enterprises, Inc. All rights reserved
//
// All use of this software is subject to the terms of the Panda 3d
// Software license. You should have received a copy of this license
// along with this source code; you will also find a current copy of
// the license at http://etc.cmu.edu/panda3d/docs/license/ .
//
// To contact the maintainers of this program write to
// panda3d-general@lists.sourceforge.net .
//
////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////
// Function: NodeCachedReferenceCount::Constructor
// Access: Protected
// Description: The ReferenceCount constructor is protected because
// you almost never want to create just a ReferenceCount
// object by itself, and it's probably a mistake if you
// try.
//
// ReferenceCount doesn't store any useful information
// in its own right; its only purpose is to add
// reference-counting to some other class via
// inheritance.
////////////////////////////////////////////////////////////////////
INLINE NodeCachedReferenceCount::
NodeCachedReferenceCount() {
_node_ref_count = 0;
}
////////////////////////////////////////////////////////////////////
// Function: NodeCachedReferenceCount::Copy Constructor
// Access: Protected
// Description: The copies of reference-counted objects do not
// themselves inherit the reference count!
//
// This copy constructor is protected because you almost
// never want to create just a ReferenceCount object by
// itself, and it's probably a mistake if you try.
////////////////////////////////////////////////////////////////////
INLINE NodeCachedReferenceCount::
NodeCachedReferenceCount(const NodeCachedReferenceCount &copy) : CachedTypedWritableReferenceCount(copy) {
_node_ref_count = 0;
}
////////////////////////////////////////////////////////////////////
// Function: NodeCachedReferenceCount::Copy Assignment Operator
// Access: Protected
// Description: The copies of reference-counted objects do not
// themselves inherit the reference count!
//
// This copy assignment operator is protected because
// you almost never want to copy just a ReferenceCount
// object by itself, and it's probably a mistake if you
// try. Instead, this should only be called from a
// derived class that implements this operator and then
// calls up the inheritance chain.
////////////////////////////////////////////////////////////////////
INLINE void NodeCachedReferenceCount::
operator = (const NodeCachedReferenceCount &copy) {
nassertv(this != NULL);
// If this assertion fails, our own pointer was recently deleted.
// Possibly you used a real pointer instead of a PointerTo at some
// point, and the object was deleted when the PointerTo went out of
// scope. Maybe you tried to create an automatic (local variable)
// instance of a class that derives from ReferenceCount. Or maybe
// your headers are out of sync, and you need to make clean in
// direct or some higher tree.
nassertv(_node_ref_count != -100);
CachedTypedWritableReferenceCount::operator = (copy);
}
////////////////////////////////////////////////////////////////////
// Function: NodeCachedReferenceCount::Destructor
// Access: Protected
// Description: The ReferenceCount destructor is protected to
// discourage users from accidentally trying to delete a
// ReferenceCount pointer directly. This is almost
// always a bad idea, since the destructor is not
// virtual, and you've almost certainly got some pointer
// to something that inherits from ReferenceCount, not
// just a plain old ReferenceCount object.
////////////////////////////////////////////////////////////////////
INLINE NodeCachedReferenceCount::
~NodeCachedReferenceCount() {
nassertv(this != NULL);
// If this assertion fails, we're trying to delete an object that
// was just deleted. Possibly you used a real pointer instead of a
// PointerTo at some point, and the object was deleted when the
// PointerTo went out of scope. Maybe you tried to create an
// automatic (local variable) instance of a class that derives from
// ReferenceCount. Or maybe your headers are out of sync, and you
// need to make clean in direct or some higher tree.
nassertv(_node_ref_count != -100);
// If this assertion fails, the reference counts are all screwed
// up altogether. Maybe some errant code stomped all over memory
// somewhere.
nassertv(_node_ref_count >= 0);
// If this assertion fails, someone tried to delete this object
// while its reference count was still positive. Maybe you tried
// to point a PointerTo at a static object (a local variable,
// instead of one allocated via new)? The test below against 0x7f
// is supposed to check for that, but it's a pretty hokey test.
// Another possibility is you inadvertently omitted a copy
// constructor for a ReferenceCount object, and then bitwise
// copied a dynamically allocated value--reference count and
// all--onto a locally allocated one.
nassertv(_node_ref_count == 0);
#ifndef NDEBUG
// Ok, all clear to delete. Now set the reference count to -100,
// so we'll have a better chance of noticing if we happen to have
// a stray pointer to it still out there.
_node_ref_count = -100;
#endif
}
////////////////////////////////////////////////////////////////////
// Function: NodeCachedReferenceCount::get_node_ref_count
// Access: Published
// Description: Returns the current reference count.
////////////////////////////////////////////////////////////////////
INLINE int NodeCachedReferenceCount::
get_node_ref_count() const {
#ifdef _DEBUG
test_ref_count_integrity();
#endif
return AtomicAdjust::get(_node_ref_count);
}
////////////////////////////////////////////////////////////////////
// Function: NodeCachedReferenceCount::node_ref
// Access: Published
// Description: Explicitly increments the reference count.
//
// 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.
////////////////////////////////////////////////////////////////////
INLINE void NodeCachedReferenceCount::
node_ref() const {
#ifdef _DEBUG
nassertv(test_ref_count_integrity());
#endif
ref();
AtomicAdjust::inc(((NodeCachedReferenceCount *)this)->_node_ref_count);
}
////////////////////////////////////////////////////////////////////
// Function: NodeCachedReferenceCount::node_unref
// Access: Published
// Description: 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; plus, we don't have a virtual destructor
// anyway.) 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.
////////////////////////////////////////////////////////////////////
INLINE bool NodeCachedReferenceCount::
node_unref() const {
#ifdef _DEBUG
nassertr(test_ref_count_integrity(), 0);
#endif
// If this assertion fails, you tried to unref an object with a
// zero reference count. Are you using ref() and unref()
// directly? Are you sure you can't use PointerTo's?
nassertr(_node_ref_count > 0, 0);
unref();
return AtomicAdjust::dec(((NodeCachedReferenceCount *)this)->_node_ref_count);
}
////////////////////////////////////////////////////////////////////
// Function: NodeCachedReferenceCount::test_ref_count_integrity
// Access: Published
// Description: Does some easy checks to make sure that the reference
// count isn't completely bogus.
////////////////////////////////////////////////////////////////////
INLINE bool NodeCachedReferenceCount::
test_ref_count_integrity() const {
#ifndef NDEBUG
return do_test_ref_count_integrity();
#else
return true;
#endif
}
////////////////////////////////////////////////////////////////////
// Function: NodeCachedReferenceCount::get_referenced_bits
// Access: Published
// Description: Returns the union of the values defined in the
// Referenced enum that represents the various things
// that appear to be holding a pointer to this object.
//
// If R_node is included, at least one node is holding a
// pointer; if R_cache is included, at least one cache
// element is.
////////////////////////////////////////////////////////////////////
INLINE int NodeCachedReferenceCount::
get_referenced_bits() const {
int result = 0;
if (get_node_ref_count() != 0) {
result |= R_node;
}
if (get_cache_ref_count() != 0) {
result |= R_cache;
}
return result;
}