.TH MPI_Rget 3 "11/12/2019" " " "MPI"

.SH NAME

MPI_Rget \-  Get data from a memory window on a remote process 

.SH SYNOPSIS

.nf

int MPI_Rget(void *origin_addr, int origin_count, MPI_Datatype

origin_datatype, int target_rank, MPI_Aint target_disp,

int target_count, MPI_Datatype target_datatype, MPI_Win win, MPI_Request * request)

.fi

.I MPI_Rget

is similar to 

.I MPI_Get

, except that it allocates a communication

request object and associates it with the request handle (the argument request)

that can be used to wait or test for completion. The completion of an 

.I MPI_Rget

operation indicates that the data is available in the origin buffer. If

origin_addr points to memory attached to a window, then the data becomes

available in the private copy of this window.

.SH INPUT PARAMETERS

.PD 0

.TP

.B origin_addr 

- Address of the buffer in which to receive the data

.PD 1

.PD 0

.TP

.B origin_count 

- number of entries in origin buffer (nonnegative integer)

.PD 1

.PD 0

.TP

.B origin_datatype 

- datatype of each entry in origin buffer (handle)

.PD 1

.PD 0

.TP

.B target_rank 

- rank of target (nonnegative integer)

.PD 1

.PD 0

.TP

.B target_disp 

- displacement from window start to the beginning of the

target buffer (nonnegative integer)

.PD 1

.PD 0

.TP

.B target_count 

- number of entries in target buffer (nonnegative integer)

.PD 1

.PD 0

.TP

.B target_datatype 

- datatype of each entry in target buffer (handle)

.PD 1

.PD 0

.TP

.B win 

- window object used for communication (handle)

.PD 1

.SH OUTPUT PARAMETERS

.PD 0

.TP

.B request 

- RMA request (handle)

.PD 1

.SH THREAD AND INTERRUPT SAFETY

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 

.I malloc

or other non-MPICH runtime routines that are themselves not interrupt-safe.

.SH NOTES FOR FORTRAN

All MPI routines in Fortran (except for 

.I MPI_WTIME

and 

.I MPI_WTICK

) have

an additional argument 

.I ierr

at the end of the argument list.  

.I 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

.I call

statement.

All MPI objects (e.g., 

.I MPI_Datatype

, 

.I MPI_Comm

) are of type 

.I INTEGER

in Fortran.

.SH ERRORS

All MPI routines (except 

.I MPI_Wtime

and 

.I 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 

.I MPI_Comm_set_errhandler

(for communicators),

.I MPI_File_set_errhandler

(for files), and 

.I MPI_Win_set_errhandler

(for

RMA windows).  The MPI-1 routine 

.I MPI_Errhandler_set

may be used but

its use is deprecated.  The predefined error handler

.I MPI_ERRORS_RETURN

may be used to cause error values to be returned.

Note that MPI does 

.B not

guarentee that an MPI program can continue past

an error; however, MPI implementations will attempt to continue whenever

possible.

.PD 0

.TP

.B MPI_SUCCESS 

- No error; MPI routine completed successfully.

.PD 1

.PD 0

.TP

.B MPI_ERR_ARG 

- Invalid argument.  Some argument is invalid and is not

identified by a specific error class (e.g., 

.I MPI_ERR_RANK

).

.PD 1

.PD 0

.TP

.B MPI_ERR_COUNT 

- Invalid count argument.  Count arguments must be 

non-negative; a count of zero is often valid.

.PD 1

.PD 0

.TP

.B MPI_ERR_RANK 

- Invalid source or destination rank.  Ranks must be between

zero and the size of the communicator minus one; ranks in a receive

(

.I MPI_Recv

, 

.I MPI_Irecv

, 

.I MPI_Sendrecv

, etc.) may also be 

.I MPI_ANY_SOURCE

\&.

.PD 1

.PD 0

.TP

.B MPI_ERR_TYPE 

- Invalid datatype argument.  Additionally, this error can

occur if an uncommitted MPI_Datatype (see 

.I MPI_Type_commit

) is used

in a communication call.

.PD 1

.PD 0

.TP

.B MPI_ERR_WIN 

- Invalid MPI window object

.PD 1

.SH SEE ALSO

MPI_Get

.br