NAME

       MPI_Win_test  -  Attempts  to  complete  an  RMA  exposure epoch; a nonblocking version of
       MPI_Win_wait

SYNTAX

C Syntax

       #include <mpi.h>
       int MPI_Win_test(MPI_Win win, int *flag)

Fortran Syntax

       USE MPI
       ! or the older form: INCLUDE 'mpif.h'
       MPI_WIN_TEST( WIN, FLAG, IERROR)
            INTEGER  WIN, IERROR

Fortran 2008 Syntax

       USE mpi_f08
       MPI_Win_test(win, flag, ierror)
            TYPE(MPI_Win), INTENT(IN) :: win
            LOGICAL, INTENT(OUT) :: flag
            INTEGER, OPTIONAL, INTENT(OUT) :: ierror

C++ Syntax

       #include <mpi.h>
       bool MPI::Win::Test() const

INPUT PARAMETERS

       win       Window object (handle)

OUTPUT PARAMETERS

       IERROR    Fortran only: Error status (integer).

       flag      The returning state of the test for epoch closure.

DESCRIPTION

       MPI_Win_test is a one-sided MPI communication synchronization call, a nonblocking  version
       of  MPI_Win_wait.  It  returns  flag  =  true  if  MPI_Win_wait would return, flag = false
       otherwise. The effect of return of MPI_Win_test with flag = true is the same as the effect
       of  a  return  of  MPI_Win_wait. If flag = false is returned, then the call has no visible
       effect.

       Invoke MPI_Win_test only where MPI_Win_wait can be invoked. Once  the  call  has  returned
       flag = true, it must not be invoked anew, until the window is posted anew.

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_Win_wait

                                           Feb 23, 2023                           MPI_Win_test(3)