MPI_Sendrecv_replace − Sends and receives using a single buffer
MPI_Sendrecv_replace(void *buf, int count, MPI_Datatype
int dest, int sendtag, int source, int recvtag,
MPI_Comm comm, MPI_Status *status)
- number of elements in send and receive buffer (integer)
- type of elements in send and receive buffer (handle)
- rank of destination (integer)
- send message tag (integer)
- rank of source (integer)
- receive message tag (integer)
- communicator (handle)
- initial address of send and receive buffer (choice)
- status object (Status)
This routine is thread-safe. This means that this routine may be safely used by multiple threads without the need for any user-provided thread locks. However, the routine is not interrupt safe. Typically, this is due to the use of memory allocation routines such as malloc or other non-MPICH runtime routines that are themselves not interrupt-safe.
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.
The status argument must be declared as an array of size MPI_STATUS_SIZE , as in integer status(MPI_STATUS_SIZE) .
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_Comm_set_errhandler (for communicators),
MPI_File_set_errhandler (for files), and
MPI_Win_set_errhandler (for RMA windows). The MPI-1
routine MPI_Errhandler_set may be used but its use is
deprecated. 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; however, MPI
implementations will attempt to continue whenever possible.
- No error; MPI routine completed successfully.
- Invalid communicator. A common error is to use a null communicator in a call (not even allowed in MPI_Comm_rank ).
- Invalid count argument. Count arguments must be non-negative; a count of zero is often valid.
- Invalid datatype argument. Additionally, this error can occur if an uncommitted MPI_Datatype (see MPI_Type_commit ) is used in a communication call.
- 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 .
- 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 .
- Message truncated on receive. The buffer size specified was too small for the received message. This is a recoverable error in the MPICH implementation.
- This error is returned when some part of the MPICH implementation is unable to acquire memory.