Line data    Source code

       1              : //
       2              : // Buffers.cpp
       3              : //   Interface for globally accessible buffer factory for communication
       4              : //
       5              : //   Data sent between MPI ranks has to be stored in a buffer for sending and receiving.
       6              : //   To reduce the number of times memory has to be allocated and freed, the buffer
       7              : //   factory interface allows buffers to be reused. This is especially relevant on
       8              : //   GPUs, as Cuda allocation calls are expensive. To avoid reallocating the buffers
       9              : //   in the case that the amount of data to be exchanged increases, when a new buffer
      10              : //   is created, an amount of memory greater than the requested size is allocated
      11              : //   for the new buffer. The factor by which memory is overallocated is determined by
      12              : //   a data member in Communicator, which can be set and queried at runtime. Only new
      13              : //   buffers are overallocated. If a buffer is requested with the same ID as a buffer
      14              : //   that has been previously allocated, the same buffer will be used. If the requested
      15              : //   size exceeds the buffer size, that buffer will be resized to have exactly
      16              : //   the requested size.
      17              : //
      18              : //   Currently, the buffer factory is used for application of periodic boundary
      19              : //   conditions; halo cell exchange along faces, edges, and vertices; as well as
      20              : //   exchanging particle data between ranks.
      21              : //
      22              : 
      23              : #include "Ippl.h"
      24              : 
      25              : #include "Communicator.h"
      26              : 
      27              : namespace ippl {
      28              :     namespace mpi {
      29              : 
      30            0 :         void Communicator::setDefaultOverallocation(double factor) {
      31            0 :             defaultOveralloc_m = factor;
      32            0 :         }
      33              : 
      34           44 :         void Communicator::deleteAllBuffers() {
      35           44 :             buffer_handlers_m.forAll([]<typename BufferHandler>(BufferHandler&& bh) {
      36           44 :                 bh.deleteAllBuffers();
      37           44 :             });
      38           44 :         }
      39              : 
      40          632 :         void Communicator::freeAllBuffers() {
      41          632 :             buffer_handlers_m.forAll([]<typename BufferHandler>(BufferHandler&& bh) {
      42          632 :                 bh.freeAllBuffers();
      43          632 :             });
      44          632 :         }
      45              : 
      46              :     }  // namespace mpi
      47              : }  // namespace ippl