NAME

       MPI_Test -  Tests for the completion of a request

SYNOPSIS

       int MPI_Test(MPI_Request *request, int *flag, MPI_Status *status)

INPUT PARAMETERS

       request
              - MPI request (handle)

OUTPUT PARAMETERS

       flag   - true if operation completed (logical)
       status - status object (Status).  May be MPI_STATUS_IGNORE .

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

NOTES ON THE MPI_STATUS ARGUMENT

       The MPI_ERROR field of the status return is only set if the return from the MPI routine is
       MPI_ERR_IN_STATUS  .  That error class is only returned by the routines that take an array
       of status arguments ( MPI_Testall , MPI_Testsome , MPI_Waitall , and MPI_Waitsome  ).   In
       all other cases, the value of the MPI_ERROR field in the status is unchanged.  See section
       3.2.5 in the MPI-1.1 specification for the exact text.

       For send operations, the only use of status is for MPI_Test_cancelled or in the case  that
       there  is  an  error  in  one  of  the  four  routines  that  may  return  the error class
       MPI_ERR_IN_STATUS , in which case the MPI_ERROR field of status  will  be  set.   In  that
       case,  the  value  will  be  set  to  MPI_SUCCESS  for  any send or receive operation that
       completed successfully, or MPI_ERR_PENDING for any operation which has neither failed  nor
       completed.

NOTES FOR FORTRAN

       All  MPI  routines  in  Fortran  (except  for MPI_WTIME and MPI_WTICK ) have an additional
       argument ierr at the end of the argument list.  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 call statement.

       All MPI objects (e.g., MPI_Datatype , MPI_Comm ) are of type INTEGER in Fortran.

       The status argument must be declared as an array of size MPI_STATUS_SIZE , as  in  integer
       status(MPI_STATUS_SIZE) .

ERRORS

       All  MPI  routines  (except MPI_Wtime and 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  MPI_Comm_set_errhandler  (for
       communicators),  MPI_File_set_errhandler  (for files), and MPI_Win_set_errhandler (for RMA
       windows).  The MPI-1 routine MPI_Errhandler_set may be used but  its  use  is  deprecated.
       The  predefined  error  handler  MPI_ERRORS_RETURN may be used to cause error values to be
       returned.  Note that MPI does not guarentee that an  MPI  program  can  continue  past  an
       error; however, MPI implementations will attempt to continue whenever possible.

       MPI_SUCCESS
              - No error; MPI routine completed successfully.
       MPI_ERR_REQUEST
              - Invalid MPI_Request .  Either null or, in the case of a MPI_Start or MPI_Startall
              , not a persistent request.
       MPI_ERR_ARG
              - Invalid argument.  Some argument is invalid and is not identified by  a  specific
              error class (e.g., MPI_ERR_RANK ).

                                            11/12/2016                                MPI_Test(3)