/**
* Set the data to a certain value (non blocking).
*
* @param push The data which must be set.
*/
virtual void Set( const DataType& push )
{
/**
* This method can not be called concurrently (only one
* producer). With a minimum of 3 buffers, if the
* write_ptr+1 field is not occupied, it will remain so
* because the read_ptr is at write_ptr-1 (and can
* not increment the counter on write_ptr+1). Hence, no
* locking is needed.
*/
// writeout in any case
write_ptr->data = push;
PtrType wrote_ptr = write_ptr;
// if next field is occupied (by read_ptr or counter),
// go to next and check again...
while ( oro_atomic_read( &write_ptr->next->counter ) != 0 || write_ptr->next == read_ptr )
{
write_ptr = write_ptr->next;
if (write_ptr == wrote_ptr)
return; // nothing found, to many readers !
}
// we will be able to move, so replace read_ptr
read_ptr = wrote_ptr;
write_ptr = write_ptr->next; // we checked this in the while loop
}
/**
* Increase the reference count of a piece of memory.
* Returns false if already released.
*/
bool lock(pointer m) {
Item* it = reinterpret_cast<Item*>(m);
if ( oro_atomic_read(&it->rc) == 0 )
return false;
oro_atomic_inc(&(it->rc) );
return true;
}
/**
* Decrease the reference count of a piece of memory \a m,
* which becomes available for allocation.
*/
bool deallocate( pointer m )
{
Item* it = reinterpret_cast<Item*>(m);
if ( oro_atomic_read(&it->rc) == 0 )
return false;
if( oro_atomic_dec_and_test( &(it->rc) ) )
if ( mpool.enqueue( static_cast<void*>(m) ) == false )
assert(false && "Deallocating more elements than allocated !");
return true;
}
/**
* Deallocate and unlock() a piece of memory.
* Returns false if already released.
*/
bool deallocate( pointer m )
{
Item* item = reinterpret_cast<Item*>(m);
if ( oro_atomic_read(&item->rc) == 0 )
return false;
if( oro_atomic_dec_and_test( &(item->rc) ) ) {
for ( typename PoolType::iterator it = mpool.begin(); it != mpool.end(); ++it ) {
if ( it->first->enqueue( static_cast<void*>(m) ) ) {
return true;
}
}
assert(false && "Deallocating more elements than allocated !");
}
return true;
}
/**
* Read the current value of the integer.
*/
int read() const { return oro_atomic_read( &_val); }
const AtomicInt& operator=(const AtomicInt& orig)
{
oro_atomic_set( &_val, oro_atomic_read( &(orig._val)));
return *this;
}
AtomicInt(const AtomicInt& orig)
{
ORO_ATOMIC_SETUP( &_val, oro_atomic_read( &(orig._val) ) );
}
/**
* Returns how many times a piece of memory
* is used.
*/
size_type useCount( pointer m ) {
return oro_atomic_read( &static_cast< Item* >(m)->rc );
}