MPI_RECV, MPI_Recv

Purpose

Performs a blocking receive operation.

C synopsis

#include <mpi.h>
int MPI_Recv(void* buf,int count,MPI_Datatype datatype,
    int source,int tag,MPI_Comm comm,MPI_Status *status);

C++ synopsis

#include mpi.h
void MPI::Comm::Recv(void* buf, int count, const MPI::Datatype& datatype,
                     int source, int tag) const;

#include mpi.h
void MPI::Comm::Recv(void* buf, int count, const MPI::Datatype& datatype,
                     int source, int tag, MPI::Status& status) const;

FORTRAN synopsis

include 'mpif.h' or use mpi
MPI_RECV(CHOICE BUF,INTEGER COUNT,INTEGER DATATYPE,INTEGER SOURCE,
      INTEGER TAG,INTEGER COMM,INTEGER STATUS(MPI_STATUS_SIZE),INTEGER IERROR)

Description

MPI_RECV is a blocking receive operation. The receive buffer is storage
containing room for count consecutive elements of the type specified by
datatype, starting at address buf.

The message received must be less than or equal to the length of the
receive buffer. If all incoming messages do not fit without truncation, an
overflow error occurs. If a message arrives that is shorter than the
receive buffer, then only those locations corresponding to the actual
message are changed.

Passing MPI_STATUS_IGNORE for the status argument causes PE MPI to skip
filling in the status fields. By passing this value for status, you can
avoid having to allocate a status object in programs that do not need to
examine the status fields.

Parameters

buf
     is the initial address of the receive buffer (choice) (OUT)
count
     is the number of elements to be received (integer) (IN)
datatype
     is the datatype of each receive buffer element (handle) (IN)
source
     is the rank of the source task in comm or MPI_ANY_SOURCE (integer)
     (IN)
tag
     is the message tag or MPI_ANY_TAG (positive integer) (IN)
comm
     is the communicator (handle) (IN)
status
     is the status object (Status) (INOUT). Note that in FORTRAN a single
     status object is an array of integers.
IERROR
     is the FORTRAN return code. It is always the last argument.

Errors

Invalid count
     count < 0

Invalid datatype

Invalid status ignore value

Type not committed

Invalid source
     source < 0 or source > = groupsize

Invalid tag
     tag < 0

Invalid comm

Truncation occurred

MPI not initialized

MPI already finalized

Related information

     MPI_IRECV
     MPI_SEND
     MPI_SENDRECV