* Copyright 2009, Axel Dörfler, axeld@pinc-software.de.
* Distributed under the terms of the MIT License.
*/
#include <WeakReferenceable.h>
#include <stdio.h>
#include <OS.h>
namespace BPrivate {
WeakPointer::WeakPointer(BWeakReferenceable* object)
:
fUseCount(1),
fObject(object)
{
}
WeakPointer::~WeakPointer()
{
}
BWeakReferenceable*
WeakPointer::Get()
{
int32 count;
do {
count = atomic_get(&fUseCount);
if (count == 0)
return NULL;
if (count < 0)
debugger("reference (use) count is negative");
} while (atomic_test_and_set(&fUseCount, count + 1, count) != count);
return fObject;
}
bool
WeakPointer::Put()
{
const int32 count = atomic_add(&fUseCount, -1);
if (count == 1) {
delete fObject;
return true;
}
if (count <= 0)
debugger("reference (use) count is negative");
return false;
}
int32
WeakPointer::UseCount() const
{
return fUseCount;
}
void
WeakPointer::GetUnchecked()
{
atomic_add(&fUseCount, 1);
}
BWeakReferenceable::BWeakReferenceable()
:
fPointer(new(std::nothrow) WeakPointer(this))
{
}
BWeakReferenceable::~BWeakReferenceable()
{
if (fPointer->UseCount() == 1)
atomic_test_and_set(&fPointer->fUseCount, 0, 1);
if (fPointer->UseCount() != 0) {
char message[256];
snprintf(message, sizeof(message), "deleting referenceable object %p with "
"reference count (%" B_PRId32 ")", this, fPointer->UseCount());
debugger(message);
}
fPointer->ReleaseReference();
}
status_t
BWeakReferenceable::InitCheck()
{
if (fPointer == NULL)
return B_NO_MEMORY;
return B_OK;
}
WeakPointer*
BWeakReferenceable::GetWeakPointer()
{
fPointer->AcquireReference();
return fPointer;
}
}
