RecyclableDataObject.icc

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/*
  Copyright (C) 2002-2025 CERN for the benefit of the ATLAS collaboration
*/
// $Id$
/*
 */
/**
 * @file AthenaKernel/RecyclableDataObject.icc
 * @author scott snyder <snyder@bnl.gov>
 * @date Oct, 2018
 * @brief Helper for recycling objects from event to event.
 */
 
 
namespace Athena {
 
 
/**
 * @brief Constructor.
 * @param queue Queue on which this object will be entered when it is released.
 * @param args... Additional arguments to pass to the @c DOBJ constructor.
 */
template <class DOBJ>
template <typename... ARGS>
RecyclableDataObject<DOBJ>::RecyclableDataObject (std::shared_ptr<queue_t> queue, ARGS&&... args)
  : DOBJ (std::forward<ARGS>(args)...),
    m_queue (std::move(queue))
{
  // Bump reference count by one so that these objects won't be deleted by StoreGate.
  this->addRef();
}
 
 
/**
 * @brief DataObject release method.
 *
 * This overrides the @c release() method of @c DataObject.
 * Once the reference count falls back to 1 (meaning that the object is no longer
 * referenced from StoreGate), we recycle the object back to the queue.
 */
template <class DOBJ>
unsigned long RecyclableDataObject<DOBJ>::release()
{
  unsigned long cnt = DOBJ::release();
  if (cnt == 1) {
    this->recycle();
    m_queue->push (this);
  }
  return cnt;
}
 
 
/** 
 * @brief Constructor.
 */
template <class DOBJ>
RecyclableDataQueue<DOBJ>::RecyclableDataQueue()
  : m_queue (std::make_shared<queue_t>())
{
}
 
 
/**
 * @brief Get an object, either a new one or one recycled from a previous event.
 * @param args... Arguments to pass to the @c DOBJ constructor if we make a new one.
 */
template <class DOBJ>
template <typename... ARGS>
DOBJ* RecyclableDataQueue<DOBJ>::get (ARGS&&... args)
{
  DOBJ* obj = nullptr;
  if (m_queue->try_pop (obj)) {
    return obj;
  }
  return new RecyclableDataObject<DOBJ> (m_queue, std::forward<ARGS>(args)...);
}
 
 
/**
 * @brief Destructor.
 *
 * Free all objects in the queue.
 */
template <class DOBJ>
RecyclableDataQueue<DOBJ>::~RecyclableDataQueue()
{
  DOBJ* obj = nullptr;
  while (m_queue->try_pop (obj)) {
    delete obj;
    obj = nullptr;
  }
}
 
 
} // namespace Athena