#include "mpi.h" int MPI_Allgather ( void *sendbuf, int sendcount, MPI_Datatype sendtype, void *recvbuf, int recvcount, MPI_Datatype recvtype, MPI_Comm comm )
|sendbuf||starting address of send buffer (choice)
|sendcount||number of elements in send buffer (integer)
|sendtype||data type of send buffer elements (handle)
|recvcount||number of elements received from any process (integer)
|recvtype||data type of receive buffer elements (handle)
The jth block of data sent from each proess is received by every process and placed in the jth block of the buffer recvbuf.
This is misleading; a better description is
The block of data sent from the jth process is received by every process and placed in the jth block of the buffer recvbuf.
This text was suggested by Rajeev Thakur.
All MPI objects (e.g., MPI_Datatype, MPI_Comm) are of type INTEGER in Fortran.
All MPI routines (except MPI_Wtime and MPI_Wtick) return an error value; C routines as the value of the function and Fortran routines in the last argument. Before the value is returned, the current MPI error handler is called. By default, this error handler aborts the MPI job. The error handler may be changed with MPI_Errhandler_set; the predefined error handler MPI_ERRORS_RETURN may be used to cause error values to be returned. Note that MPI does not guarentee that an MPI program can continue past an error.