:ref:`MPI_Testany` - Tests for completion of any one previously initiated communication in a list.
#include <mpi.h>
int MPI_Testany(int count, MPI_Request array_of_requests[],
int *index, int *flag, MPI_Status *status)
USE MPI
! or the older form: INCLUDE 'mpif.h'
MPI_TESTANY(COUNT, ARRAY_OF_REQUESTS, INDEX, FLAG, STATUS, IERROR)
LOGICAL FLAG
INTEGER COUNT, ARRAY_OF_REQUESTS(*), INDEX
INTEGER STATUS(MPI_STATUS_SIZE), IERROR
USE mpi_f08
MPI_Testany(count, array_of_requests, index, flag, status, ierror)
INTEGER, INTENT(IN) :: count
TYPE(MPI_Request), INTENT(INOUT) :: array_of_requests(count)
INTEGER, INTENT(OUT) :: index
LOGICAL, INTENT(OUT) :: flag
TYPE(MPI_Status) :: status
INTEGER, OPTIONAL, INTENT(OUT) :: ierror
count
: List length (integer).array_of_requests
: Array of requests (array of handles).
index
: Index of operation that completed, orMPI_UNDEFINED
if none completed (integer).flag
: True if one of the operations is complete (logical).status
: Status object (status).ierror
: Fortran only: Error status (integer).
:ref:`MPI_Testany` tests for completion of either one or none of the operations
associated with active handles. In the former case, it returns flag =
true, returns in index the index of this request in the array, and
returns in status the status of that operation; if the request was
allocated by a nonblocking communication call then the request is
deallocated and the handle is set to MPI_REQUEST_NULL
. (The array is
indexed from 0 in C, and from 1 in Fortran.) In the latter case (no
operation completed), it returns flag = false, returns a value of
MPI_UNDEFINED
in index, and status is undefined.
The array may contain null or inactive handles. If the array contains no
active handles then the call returns immediately with flag = true,
index = MPI_UNDEFINED
, and an empty status.
If the array of requests contains active handles then the execution of
MPI_Testany(count, array_of_requests, index, status)
has the same effect
as the execution of MPI_Test(&array_of_requests[i], flag, status)
,
for i=0,1,...,count-1, in some arbitrary order, until one
call returns flag = true
, or all fail. In the former case, index is
set to the last value of i, and in the latter case, it is set to
MPI_UNDEFINED
. :ref:`MPI_Testany` with an array containing one active entry is
equivalent to :ref:`MPI_Test`.
If your application does not need to examine the status field, you can
save resources by using the predefined constant MPI_STATUS_IGNORE
as a
special value for the status argument.
Note that per MPI-1 section 3.2.5, MPI errors on requests passed to
:ref:`MPI_TESTANY` do not set the status.MPI_ERROR
field in the returned
status. The error code is passed to the back-end error handler and may
be passed back to the caller through the return value of :ref:`MPI_TESTANY` if
the back-end error handler returns it. The pre-defined MPI error handler
MPI_ERRORS_RETURN
exhibits this behavior, for example.
.. seealso::
* :ref:`MPI_Comm_set_errhandler`
* :ref:`MPI_File_set_errhandler`
* :ref:`MPI_Test`
* :ref:`MPI_Testall`
* :ref:`MPI_Testsome`
* :ref:`MPI_Wait`
* :ref:`MPI_Waitall`
* :ref:`MPI_Waitany`
* :ref:`MPI_Waitsome`
* :ref:`MPI_Win_set_errhandler`