ClusterFinderMT

template<typename ClusterType = Cluster<int32_t, 3, 3>, typename FRAME_TYPE = uint16_t, typename PEDESTAL_TYPE = double, typename = std::enable_if_t<no_2x2_cluster<ClusterType>::value>>
class ClusterFinderMT

ClusterFinderMT is a multi-threaded version of ClusterFinder. It uses a producer-consumer queue to distribute the frames to the threads. The clusters are collected in a single output queue.

Template Parameters:

  • FRAME_TYPE – type of the frame data

  • PEDESTAL_TYPE – type of the pedestal data

  • CT – type of the cluster data

Public Functions

inline ClusterFinderMT(Shape<2> image_size, PEDESTAL_TYPE nSigma = 5.0, size_t capacity = 2000, size_t n_threads = 3, size_t queue_depth = 16, size_t min_pedestal_samples = 1000)

Construct a new ClusterFinderMT object.

Parameters:

  • image_size – size of the image

  • cluster_size – size of the cluster

  • nSigma – number of sigma above the pedestal to consider a photon

  • capacity – initial capacity of the cluster vector. Should match expected number of clusters in a frame per frame.

  • n_threads – number of threads to use

  • queue_depth – number of frame buffers per thread. These are allocated once and recycled, so the total resident frame memory is n_threads * queue_depth * frame size. Keeping the in flight data below the L3 size keeps the per frame copy cheap.

  • min_pedestal_samples – minimum number of pedestal samples to accumulate before using the pedestal

inline ProducerConsumerQueue<ClusterVector<ClusterType>> *sink()

Return the sink queue where all the clusters are collected.

Warning

You need to empty this queue otherwise the cluster finder will wait forever

inline void start()

Start all processing threads.

inline void stop()

Stop all processing threads.

inline void sync()

Wait for all the queues to be empty. Mostly used for timing tests.

inline void push_pedestal_frame(NDView<FRAME_TYPE, 2> frame)

Push a pedestal frame to all the cluster finders. The frames is expected to be dark. No photon finding is done. Just pedestal update.

inline void find_clusters(NDView<FRAME_TYPE, 2> frame, uint64_t frame_number = 0)

Push the frame to the queue of the next available thread. Function returns once the frame is in a queue.

Note

Spin locks with a default wait if the queue is full.

inline void clear_pedestal()
inline void update_threshold()

Recompute the threshold (nSigma * pedestal std) on all cluster finders. Requires the processing threads to be stopped.

inline auto pedestal(size_t thread_index = 0)

Return the pedestal currently used by the cluster finder.

Parameters:

thread_index – index of the thread

inline auto noise(size_t thread_index = 0)

Return the noise currently used by the cluster finder.

Parameters:

thread_index – index of the thread

inline void set_nSigma(const PEDESTAL_TYPE nSigma)

Set the nSigma value for all the cluster finders. Waits for the queued frames to be processed first.

Parameters:

nSigma – number of sigma above the pedestal to consider a photon during cluster finding.

inline bool pedestal_ready()

Return whether all cluster finders have received enough pedestal frames to find clusters. Waits for the queued frames to be processed first.