# MPI_Irecv

Nonblocking receive of data from a node

## Calling Sequence

    MPI_Irecv(rank,tag)

## Arguments

rank

  The rank. TODO

tag

  The tag. TODO

## Description

Receive a variable from a specified node in a nonblock (asynchronous) way. The value is usually sent by the function MPI_Isend.

Note that, due to its asynchronous nature, MPI_Irecv does not return any value. The value sent by the source node will be returned by MPI_Wait.

## Technical implementation

For more information on the implementation of Scilab/MPI, please see Technical details about the implementation

## Examples

## Examples

                    MPI_Init();
                    rnk =    MPI_Comm_rank();
                    sizeNodes =    MPI_Comm_size();

                    SLV = rnk;
                    Master = ~ SLV;

                    assert_checkequal(MPI_Comm_size(), 2);

                    if Master
                       for slaveId = 1:sizeNodes-1
                         value = slaveId*2
                         MPI_Isend(value, slaveId, 42);
                       end
                    else
                        rankSource=0;
                        tag=0;
                        MPI_Irecv(rankSource, tag, 42); // MPI_Irecv does not return any value
                        value=MPI_Wait(42) // the value will be returned by MPI_Wait
                        assert_checkequal(value,2);
                    end

                    MPI_Finalize();
                    exit()

## See Also

- MPI_Isend
- MPI_Wait