MPI_Irecv(3)                       Open MPI                       MPI_Irecv(3)



NAME
       MPI_Irecv - Starts a standard-mode, nonblocking receive.


SYNTAX
C Syntax
       #include <mpi.h>
       int MPI_Irecv(void *buf, int count, MPI_Datatype datatype,
               int source, int tag, MPI_Comm comm, MPI_Request *request)


Fortran Syntax
       INCLUDE 'mpif.h'
       MPI_IRECV(BUF, COUNT, DATATYPE, SOURCE, TAG, COMM, REQUEST,
                 IERROR)
            <type>    BUF(*)
            INTEGER   COUNT, DATATYPE, SOURCE, TAG, COMM, REQUEST, IERROR


C++ Syntax
       #include <mpi.h>
       Request Comm::Irecv(void* buf, int count, const Datatype&
            datatype, int source, int tag) const


INPUT PARAMETERS
       buf       Initial address of receive buffer (choice).

       count     Number of elements in receive buffer (integer).

       datatype  Datatype of each receive buffer element (handle).

       source    Rank of source (integer).

       tag       Message tag (integer).

       comm      Communicator (handle).


OUTPUT PARAMETERS
       request   Communication request (handle).

       IERROR    Fortran only: Error status (integer).


DESCRIPTION
       Nonblocking calls allocate a communication request object and associate
       it with the request handle (the argument request). The request can be
       used later to query the status of the communication or wait for its
       completion.

       A nonblocking receive call indicates that the system may start writing
       data into the receive buffer. The receiver should not access any part
       of the receive buffer after a nonblocking receive operation is called,
       until the receive completes.

       A receive request can be determined being completed by calling the
       MPI_Wait, MPI_Waitany, MPI_Test, or MPI_Testany with request returned
       by this function.


ERRORS
       Almost all MPI routines return an error value; C routines as the value
       of the function and Fortran routines in the last argument. C++
       functions do not return errors. If the default error handler is set to
       MPI::ERRORS_THROW_EXCEPTIONS, then on error the C++ exception mechanism
       will be used to throw an MPI:Exception object.

       Before the error value is returned, the current MPI error handler is
       called. By default, this error handler aborts the MPI job, except for
       I/O function errors. The error handler may be changed with
       MPI_Comm_set_errhandler; the predefined error handler MPI_ERRORS_RETURN
       may be used to cause error values to be returned. Note that MPI does
       not guarantee that an MPI program can continue past an error.


SEE ALSO
       MPI_Recv MPI_Probe MPI_Test MPI_Testany MPI_Wait MPI_Waitany




1.4.1                            Jan 14, 2010                     MPI_Irecv(3)
