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
- 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