NAME

       MPI_Bsend_init -  Builds a handle for a buffered send

SYNOPSIS

       #include <mpi.h>
       int MPI_Bsend_init(void *buf, int count, MPI_Datatype dtype,
                         int dest, int tag, MPI_Comm comm,
                         MPI_Request *req)

INPUT PARAMETERS

       buf    - initial address of send buffer (choice)
       count  - number of elements sent (integer)
       dtype  - type of each element (handle)
       dest   - rank of destination (integer)
       tag    - message tag (integer)
       comm   - communicator (handle)

OUTPUT PARAMETER

       req    - communication request (handle)

NOTES

       It  is  generally a bad idea to use the MPI_Bsend_init function, as it guarantees that the
       entire message will suffer the overhead of an additional memory copy.  For large messages,
       or  when  shared  memory  message  transports  are  being used, this overhead can be quite
       expensive.

       The communication initialized by this function will not be started until req is  given  to
       MPI_Start or MPI_Startall .

       The  communication is then not guaranteed to progress or complete until req has been given
       to one of the test or wait functions ( MPI_Test , MPI_Testall , MPI_Testany , MPI_Testsome
       , MPI_Wait , MPI_Waitall , MPI_Waitany , MPI_Waitsome ).

       Once  any  of the test or wait functions indicate that the communication has finished, the
       communication cycle can be started again with MPI_Start or MPI_Startall .

       However, once the communication has finished and it is no longer going  to  be  used,  req
       should be freed with MPI_Request_free .

NOTES FOR FORTRAN

       All  MPI  routines  in  Fortran  (except  for MPI_WTIME and MPI_WTICK ) have an additional
       argument ierr at the end of the argument list.  ierr  is  an  integer  and  has  the  same
       meaning  as  the  return  value  of  the  routine  in  C.   In  Fortran,  MPI routines are
       subroutines, and are invoked with the call statement.

       All MPI objects (e.g., MPI_Datatype , MPI_Comm ) are of type INTEGER in Fortran.

ERRORS

       If an error occurs in an MPI function, the current MPI error handler is called  to  handle
       it.   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 (in C and Fortran; this error handler is less useful in
       with the C++ MPI bindings.   The  predefined  error  handler  MPI::ERRORS_THROW_EXCEPTIONS
       should  be  used in C++ if the error value needs to be recovered).  Note that MPI does not
       guarantee that an MPI program can continue past an error.

       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.  The C++ bindings for
       MPI do not return error  values;  instead,  error  values  are  communicated  by  throwing
       exceptions of type MPI::Exception (but not by default).  Exceptions are only thrown if the
       error value is not MPI::SUCCESS .

       Note that if the MPI::ERRORS_RETURN handler is set in C++, while MPI functions will return
       upon an error, there will be no way to recover what the actual error value was.
       MPI_SUCCESS
              - No error; MPI routine completed successfully.
       MPI_ERR_COMM
              -  Invalid  communicator.   A  common error is to use a null communicator in a call
              (not even allowed in MPI_Comm_rank ).
       MPI_ERR_COUNT
              - Invalid count argument.  Count arguments must be non-negative; a count of zero is
              often valid.
       MPI_ERR_TYPE
              -   Invalid   datatype   argument.    May   be  an  uncommitted  MPI_Datatype  (see
              MPI_Type_commit ).
       MPI_ERR_RANK
              - Invalid source or destination rank.  Ranks must be between zero and the  size  of
              the  communicator  minus  one;  ranks  in  a  receive  (  MPI_Recv  ,  MPI_Irecv  ,
              MPI_Sendrecv , etc.) may also be MPI_ANY_SOURCE .

       MPI_ERR_TAG
              - Invalid tag argument.  Tags must be non-negative; tags in a receive ( MPI_Recv  ,
              MPI_Irecv  , MPI_Sendrecv , etc.)  may also be MPI_ANY_TAG .  The largest tag value
              is available through the the attribute MPI_TAG_UB .

SEE ALSO

       MPI_Buffer_attach,  MPI_Buffer_detach,  MPI_Bsend,  MPI_Start,   MPI_Startall,   MPI_Test,
       MPI_Testall, MPI_Testany, MPI_Testsome, MPI_Wait, MPI_Waitall, MPI_Waitany, MPI_Waitsome

MORE INFORMATION

       For  more information, please see the official MPI Forum web site, which contains the text
       of both the MPI-1 and MPI-2 standards.  These documents contain detailed information about
       each MPI function (most of which is not duplicated in these man pages).

       http://www.mpi-forum.org/

ACKNOWLEDGEMENTS

       The  LAM  Team  would  like the thank the MPICH Team for the handy program to generate man
       pages  ("doctext"  from  ftp://ftp.mcs.anl.gov/pub/sowing/sowing.tar.gz  ),  the   initial
       formatting, and some initial text for most of the MPI-1 man pages.

LOCATION

       bsendinit.c