.. _mpi_testall:


MPI_Testall
===========

.. include_body

:ref:`MPI_Testall` |mdash| Tests for the completion of all previously initiated
communications in a list.


SYNTAX
------


C Syntax
^^^^^^^^

.. code-block:: c

   #include <mpi.h>

   int MPI_Testall(int count, MPI_Request array_of_requests[],
   	int *flag, MPI_Status array_of_statuses[])


Fortran Syntax
^^^^^^^^^^^^^^

.. code-block:: fortran

   USE MPI
   ! or the older form: INCLUDE 'mpif.h'
   MPI_TESTALL(COUNT, ARRAY_OF_REQUESTS, FLAG, ARRAY_OF_STATUSES,
   		IERROR)
   	LOGICAL	FLAG
   	INTEGER	COUNT, ARRAY_OF_REQUESTS(*)
   	INTEGER	ARRAY_OF_STATUSES(MPI_STATUS_SIZE,*), IERROR


Fortran 2008 Syntax
^^^^^^^^^^^^^^^^^^^

.. code-block:: fortran

   USE mpi_f08
   MPI_Testall(count, array_of_requests, flag, array_of_statuses, ierror)
   	INTEGER, INTENT(IN) :: count
   	TYPE(MPI_Request), INTENT(INOUT) :: array_of_requests(count)
   	LOGICAL, INTENT(OUT) :: flag
   	TYPE(MPI_Status) :: array_of_statuses(*)
   	INTEGER, OPTIONAL, INTENT(OUT) :: ierror


INPUT PARAMETERS
----------------
* ``count``: Lists length (integer).
* ``array_of_requests``: Array of requests (array of handles).

OUTPUT PARAMETERS
-----------------
* ``flag``: True if previously initiated communications are complete (logical.)
* ``array_of_statuses``: Array of status objects (array of status).
* ``ierror``: Fortran only: Error status (integer).

DESCRIPTION
-----------

Returns *flag* = true if all communications associated with active
handles in the array have completed (this includes the case where no
handle in the list is active). In this case, each status entry that
corresponds to an active handle request is set to the status of the
corresponding communication; if the request was allocated by a
nonblocking communication call then it is deallocated, and the handle is
set to MPI_REQUEST_NULL. Each status entry that corresponds to a null or
inactive handle is set to empty.

Otherwise, *flag* = false is returned, no request is modified and the
values of the status entries are undefined. This is a local operation.

If your application does not need to examine the *array_of_statuses*
field, you can save resources by using the predefined constant
MPI_STATUSES_IGNORE can be used as a special value for the
*array_of_statuses* argument.

Errors that occurred during the execution of :ref:`MPI_Testall` are handled in
the same manner as errors in :ref:`MPI_Waitall`.


NOTE
----

*flag* is true only if all requests have completed. Otherwise, *flag* is
false, and neither *array_of_requests* nor *array_of_statuses* is
modified.


ERRORS
------

.. include:: ./ERRORS.rst

For each invocation of :ref:`MPI_Testall`, if one or more requests
generate an MPI error, only the *first* MPI request that caused an
error will be passed to its corresponding error handler. No other
error handlers will be invoked (even if multiple requests generated
errors). However, *all* requests that generate an error will have a
relevant error code set in the corresponding ``status.MPI_ERROR``
field (unless ``MPI_STATUSES_IGNORE`` was used).

If the invoked error handler allows :ref:`MPI_Testall` to return to
the caller, the value ``MPI_ERR_IN_STATUS`` will be returned in the C
and Fortran bindings.


.. seealso::
   * :ref:`MPI_Comm_set_errhandler`
   * :ref:`MPI_File_set_errhandler`
   * :ref:`MPI_Test`
   * :ref:`MPI_Testany`
   * :ref:`MPI_Testsome`
   * :ref:`MPI_Wait`
   * :ref:`MPI_Waitall`
   * :ref:`MPI_Waitany`
   * :ref:`MPI_Waitsome`
   * :ref:`MPI_Win_set_errhandler`
