Figure 4.

Two-tier connection infrastructure for spiking and continuous-data connections on each MPI process. All components of the connection infrastructure hold data separated by thread using a resizable array of pointers to the thread-local data structures (top, black). (A) Postsynaptic side. The receiver side of the connection infrastructure consists of three identically structured parts: the connection table (left), the source table (middle), and the table of receive-buffer positions for continuous-data connections (right). Connection table: Thread-specific resizable arrays store pointers to variable-sized containers for every synapse type. If a synapse type is in use, the corresponding container (orange filled rectangle) stores all thread-local connections of this type in a resizable array; both spiking connections (pink filled squares) and continuous-data connections (green filled squares) are stored. Synapse types can differ in memory consumption per object, indicated by different sizes of the synapse objects. Source table: Source objects (dark red filled squares) are stored in a three-dimensional resizable array, with a one-to-one relation between each source object and the connection object in the same location in the connection table. Sources contain the GIDs of the presynaptic neurons. Table of receive-buffer positions: Thread-specific two-dimensional resizable arrays store receive-buffer positions (turquoise filled squares) for all continuous-data connections, with a one-to-one relation between each buffer position and the continuous-data connection object in the same location in the connection table. (B) Presynaptic side. The sender side of the connection infrastructure consists of the target table (left) and the table of send-buffer positions for continuous-data connections (right). Target table: Thread-specific two-dimensional resizable arrays store the target objects (yellow filled squares) for every thread-local neuron. The target objects contain the locations of the targets in terms of the MPI ranks and the locations in the corresponding connection table on the postsynaptic side. Table of send-buffer positions: Thread-specific three-dimensional arrays store the send-buffer positions (blue filled squares) for the outgoing continuous-data connections of every thread-local neuron. Adapted from Jordan et al. (2018) under CC BY 4.0 (http://creativecommons.org/licenses/by/4.0/).