MPI_Testany(3OpenMPI) MPI_Testany(3OpenMPI)
NAME
MPI_Testany - Tests for completion of any one previously initiated com-
munication in a list.
SYNTAX
C Syntax
#include <mpi.h>
int MPI_Testany(int count, MPI_Request *array_of_requests,
int *index, int *flag, MPI_Status *status)
Fortran Syntax
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
C++ Syntax
#include <mpi.h>
static bool Request::Testany(int count, Request array_of_requests[],
int& index, Status& status)
static bool Request::Testany(int count, Request array_of_requests[],
int& index)
INPUT PARAMETERS
count List length (integer).
array_of_requests
Array of requests (array of handles).
OUTPUT PARAMETERS
index Index of operation that completed, or MPI_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).
DESCRIPTION
MPI_Testany tests for completion of either one or none of the opera-
tions 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 deal-
located 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, sta-
tus), 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_UNDE-
FINED. MPI_Testany with an array containing one active entry is equiva-
lent to 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.
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++ func-
tions 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_Comm_set_errhandler, MPI_File_set_errhandler, or
MPI_Win_set_errhandler (depending on the type of MPI handle that gener-
ated the request); 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.
Note that per MPI-1 section 3.2.5, MPI exceptions on requests passed to
MPI_TESTANY do not set the status.MPI_ERROR field in the returned sta-
tus. The error code is passed to the back-end error handler and may be
passed back to the caller through the return value of MPI_TESTANY if
the back-end error handler returns it. The pre-defined MPI error han-
dler MPI_ERRORS_RETURN exhibits this behavior, for example.
SEE ALSO
MPI_Comm_set_errhandler(3), MPI_File_set_errhandler(3), MPI_Test(3),
MPI_Testall(3), MPI_Testsome(3), MPI_Wait(3), MPI_Waitall(3),
MPI_Waitany(3), MPI_Waitsome(3), MPI_Win_set_errhandler(3)
Open MPI 1.2 September 2006 MPI_Testany(3OpenMPI)
Mac OS X 10.6 - Generated Thu Sep 17 20:13:16 CDT 2009