# MPI_Win_wait

## NAME

MPI_Win_wait − Completes an RMA exposure epoch started by a call to MPI_Win_post on win

## SYNTAX

## C Syntax

#include <mpi.h>
int MPI_Win_wait(MPI_Win win)

## Fortran Syntax

INCLUDE ’mpif.h’
MPI_WIN_WAIT( WIN, IERROR)

|  | INTEGER WIN, IERROR

## C++ Syntax

#include <mpi.h>
void MPI::Win::Wait() const

## INPUT PARAMETERS

| win |  | Window object (handle). |

## OUTPUT PARAMETERS

| IERROR |  | Fortran only: Error status (integer). |

## DESCRIPTION

MPI_Win_wait is a one-sided MPI communication synchronization call that completes an RMA exposure epoch started by a call to MPI_Win_post on win. This call matches calls to MPI_Win_complete(win) issued by each of the processes that were granted access to the window during this epoch. The call to MPI_Win_wait blocks until all matching calls to MPI_Win_complete have occurred. This guarantees that all these origin processes have completed their RMA accesses to the local window. When the call returns, all these RMA accesses will have completed at the target window.

## 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_Win_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_Win_post

MPI API Index