


MPI_Comm_connect(3)          LAM/MPI          MPI_Comm_connect(3)


NAME
       MPI_Comm_connect -  Make a connection to another MPI process

SYNOPSIS
       #include <mpi.h>
       int
       MPI_Comm_connect(char *port_name, MPI_Info info, int root, MPI_Comm comm,
          MPI_Comm *newcomm)

INPUT PARAMETERS
       port_name
              - port name (only used at root)
       info   - extra information handle (only used at root)
       root   - rank in comm of root node
       comm   - intracommunicator over which the call is collective


OUTPUT PARAMETER
       newcomm
              - intercommunicator with server as remote group


DESCRIPTION
       The MPI_Comm_accept and MPI_Comm_connect calls simulate the well-under-
       stood accept() / connect() semantics of standard socket programming  --
       a client "connects" to a server.

       LAM/MPI allows for previously-unrelated MPI programs to join into a MPI
       program with these calls.  Both MPI programs must  be  running  by  the
       same user in the same LAM universe (i.e., in the scope of a single lam-
       boot).


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.


USAGE WITH IMPI EXTENSIONS
       The  IMPI standard only supports MPI-1 functions.  Hence, this function
       is currently not designed to operate within an IMPI job.


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



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MPI_Comm_connect(3)          LAM/MPI          MPI_Comm_connect(3)


       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  val-
       ues;  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 commu-
              nicator in a call (not even allowed in MPI_Comm_rank ).
       MPI_ERR_ROOT
              - Invalid root.  The root must be specified as  a  rank  in  the
              communicator.   Ranks  must  be between zero and the size of the
              communicator minus one.
       MPI_ERR_ARG
              - Invalid argument.  Some argument is invalid and is not identi-
              fied  by  a  specific  error  class.   This  is typically a NULL
              pointer or other such error.
       MPI_ERR_INTERN
              - An internal error has been detected.  This is  fatal.   Please
              send  a  bug report to the LAM mailing list (see http://www.lam-
              mpi.org/contact.php ).
       MPI_ERR_OTHER
              - Other error; use  MPI_Error_string  to  get  more  information
              about this error code.
       MPI_ERR_FLAGS
              -  Mismatch of run-time flags.  For example, an MPI process that
              is running in lamd mode cannot spawn or be connected to  a  pro-
              cess that is running in c2c mode.


SEE ALSO
       MPI_Close_port(3), MPI_Comm_accept(3), MPI_Open_port(3)


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  docu-
       ments  contain  detailed  information  about each MPI function (most of
       which is not duplicated in these man pages).

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



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MPI_Comm_connect(3)          LAM/MPI          MPI_Comm_connect(3)


LOCATION
       connect.c























































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