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openmpi/ompi/mpi/c/finalized.c
Jeff Squyres 35438ae9b5 mpi/finalized: revamp INITIALIZED/FINALIZED
Per MPI-3.1:8.7.1 p361:11-13, it's valid for MPI_FINALIZED to be
invoked during an attribute destruction callback (e.g., during the
destruction of keyvals on MPI_COMM_SELF during the very beginning of
MPI_FINALIZE).  In such cases, MPI_FINALIZED must return "false".

Prior to this commit, we hung in FINALIZED if it were invoked during
a COMM_SELF attribute destruction callback in FINALIZE.  See
https://github.com/open-mpi/ompi/issues/5084.

This commit converts the MPI_INITIALIZED / MPI_FINALIZED
infrastructure to use a single enum (ompi_mpi_state, set atomically)
to represent the state of MPI:

- not initialized
- init started
- init completed
- finalize started
- finalize past COMM_SELF destruction
- finalize completed

The "finalize past COMM_SELF destruction" state is what allows us to
return "false" from MPI_FINALIZED before COMM_SELF has been fully
destroyed / all attribute callbacks have been invoked.

Since this state is checked at nearly every MPI API call (to see if
we're outside of the INIT/FINALIZE epoch), care was taken to use
atomics to *set* the ompi_mpi_state value in ompi_mpi_init() and
ompi_mpi_finalize(), but performance-critical code paths can simply
read the variable without needing to use a slow call to an
opal_atomic_*() function.

Thanks to @AndrewGaspar for reporting the issue.

Signed-off-by: Jeff Squyres <jsquyres@cisco.com>
2018-06-01 13:36:29 -07:00

76 строки
2.5 KiB
C

/*
* Copyright (c) 2004-2007 The Trustees of Indiana University and Indiana
* University Research and Technology
* Corporation. All rights reserved.
* Copyright (c) 2004-2005 The University of Tennessee and The University
* of Tennessee Research Foundation. All rights
* reserved.
* Copyright (c) 2004-2005 High Performance Computing Center Stuttgart,
* University of Stuttgart. All rights reserved.
* Copyright (c) 2004-2005 The Regents of the University of California.
* All rights reserved.
* Copyright (c) 2015 Research Organization for Information Science
* and Technology (RIST). All rights reserved.
* Copyright (c) 2015-2018 Cisco Systems, Inc. All rights reserved
* Copyright (c) 2015 Intel, Inc. All rights reserved
* $COPYRIGHT$
*
* Additional copyrights may follow
*
* $HEADER$
*/
#include "ompi_config.h"
#include "ompi/mpi/c/bindings.h"
#include "ompi/runtime/params.h"
#include "ompi/communicator/communicator.h"
#include "ompi/errhandler/errhandler.h"
#include "ompi/mca/hook/base/base.h"
#if OMPI_BUILD_MPI_PROFILING
#if OPAL_HAVE_WEAK_SYMBOLS
#pragma weak MPI_Finalized = PMPI_Finalized
#endif
#define MPI_Finalized PMPI_Finalized
#endif
static const char FUNC_NAME[] = "MPI_Finalized";
int MPI_Finalized(int *flag)
{
OPAL_CR_NOOP_PROGRESS();
ompi_hook_base_mpi_finalized_top(flag);
int32_t state = ompi_mpi_state;
if (MPI_PARAM_CHECK) {
if (NULL == flag) {
/* If we have an error, the action that we take depends on
whether we're currently (after MPI_Init and before
MPI_Finalize) or not */
if (state >= OMPI_MPI_STATE_INIT_COMPLETED &&
state < OMPI_MPI_STATE_FINALIZE_PAST_COMM_SELF_DESTRUCT) {
return OMPI_ERRHANDLER_INVOKE(MPI_COMM_WORLD, MPI_ERR_ARG,
FUNC_NAME);
} else {
/* We have no MPI object here so call ompi_errhandle_invoke
* directly */
return ompi_errhandler_invoke(NULL, NULL, -1,
ompi_errcode_get_mpi_code(MPI_ERR_ARG),
FUNC_NAME);
}
}
}
*flag = (state >= OMPI_MPI_STATE_FINALIZE_PAST_COMM_SELF_DESTRUCT);
ompi_hook_base_mpi_finalized_bottom(flag);
return MPI_SUCCESS;
}