src/gmxlib/thread_mpi/bcast.c

   1 /*
   2 This source code file is part of thread_mpi.
   3 Written by Sander Pronk, Erik Lindahl, and possibly others.
   4
   5 Copyright (c) 2009, Sander Pronk, Erik Lindahl.
   6 All rights reserved.
   7
   8 Redistribution and use in source and binary forms, with or without
   9 modification, are permitted provided that the following conditions are met:
  10 1) Redistributions of source code must retain the above copyright
  11    notice, this list of conditions and the following disclaimer.
  12 2) Redistributions in binary form must reproduce the above copyright
  13    notice, this list of conditions and the following disclaimer in the
  14    documentation and/or other materials provided with the distribution.
  15 3) Neither the name of the copyright holders nor the
  16    names of its contributors may be used to endorse or promote products
  17    derived from this software without specific prior written permission.
  18
  19 THIS SOFTWARE IS PROVIDED BY US ''AS IS'' AND ANY
  20 EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  21 WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  22 DISCLAIMED. IN NO EVENT SHALL WE BE LIABLE FOR ANY
  23 DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  24 (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  25 LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  26 ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  27 (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  28 SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  29
  30 If you want to redistribute modifications, please consider that
  31 scientific software is very special. Version control is crucial -
  32 bugs must be traceable. We will be happy to consider code for
  33 inclusion in the official distribution, but derived work should not
  34 be called official thread_mpi. Details are found in the README & COPYING
  35 files.
  36 */
  37
  38
  39 /* this file is to be #included from collective.c */
  40
  41 /* broadcast */
  42 int tMPI_Bcast(void* buffer, int count, tMPI_Datatype datatype, int root,
  43                tMPI_Comm comm)
  44 {
  45     int synct;
  46     struct coll_env *cev;
  47     int myrank;
  48     int ret=TMPI_SUCCESS;
  49     struct tmpi_thread *cur=tMPI_Get_current();
  50
  51 #ifdef TMPI_PROFILE
  52     tMPI_Profile_count_start(cur);
  53 #endif
  54 #ifdef TMPI_TRACE
  55     tMPI_Trace_print("tMPI_Bcast(%p, %d, %p, %d, %p)", buffer, count, datatype,
  56                      root, comm);
  57 #endif
  58
  59     if (!comm)
  60     {
  61         return tMPI_Error(TMPI_COMM_WORLD, TMPI_ERR_COMM);
  62     }
  63     myrank=tMPI_Comm_seek_rank(comm, cur);
  64
  65     /* we increase our counter, and determine which coll_env we get */
  66     cev=tMPI_Get_cev(comm, myrank, &synct);
  67
  68     if (myrank==root)
  69     {
  70         /* first set up the data */
  71         tMPI_Post_multi(cev, myrank, 0, TMPI_BCAST_TAG, datatype,
  72                         count*datatype->size, buffer, comm->grp.N-1, synct, -1);
  73         /* and wait until everybody is done copying */
  74         tMPI_Wait_for_others(cev, myrank);
  75     }
  76     else
  77     {
  78         size_t bufsize=count*datatype->size;
  79         /* wait until root becomes available */
  80         tMPI_Wait_for_data(cur, cev, myrank);
  81         tMPI_Mult_recv(comm, cev, root, 0, TMPI_BCAST_TAG, datatype, bufsize,
  82                        buffer, &ret);
  83     }
  84 #ifdef TMPI_PROFILE
  85     tMPI_Profile_count_stop(cur, TMPIFN_Bcast);
  86 #endif
  87     return ret;
  88 }
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