110 строки
3.8 KiB
C
110 строки
3.8 KiB
C
/*
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* Copyright (c) 2004-2008 The Trustees of Indiana University and Indiana
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* University Research and Technology
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* Corporation. All rights reserved.
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* Copyright (c) 2004-2005 The University of Tennessee and The University
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* of Tennessee Research Foundation. All rights
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* reserved.
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* Copyright (c) 2004-2005 High Performance Computing Center Stuttgart,
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* University of Stuttgart. All rights reserved.
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* Copyright (c) 2004-2005 The Regents of the University of California.
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* All rights reserved.
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* Copyright (c) 2007-2010 Cisco Systems, Inc. All rights reserved.
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* Copyright (c) 2008 Sun Microsystems, Inc. All rights reserved.
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* Copyright (c) 2010-2011 Los Alamos National Security, LLC.
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* All rights reserved.
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* Copyright (c) 2011 NVIDIA Corporation. All rights reserved.
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*
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* $COPYRIGHT$
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*
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* Additional copyrights may follow
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*
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* $HEADER$
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*/
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#include "opal_config.h"
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#include <errno.h>
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#ifdef HAVE_FCNTL_H
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#include <fcntl.h>
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#endif /* HAVE_FCNTL_H */
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#ifdef HAVE_STRING_H
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#include <string.h>
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#endif /* HAVE_STRING_H */
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#ifdef HAVE_SYS_MMAN_H
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#include <sys/mman.h>
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#endif /* HAVE_SYS_MMAN_H */
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#ifdef HAVE_UNISTD_H
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#include <unistd.h>
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#endif /* HAVE_UNISTD_H */
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#ifdef HAVE_SYS_TYPES_H
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#include <sys/types.h>
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#endif /* HAVE_SYS_TYPES_H */
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#ifdef HAVE_NETDB_H
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#include <netdb.h>
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#endif /* HAVE_NETDB_H */
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#include "opal/util/output.h"
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#include "opal/util/show_help.h"
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#include "opal/mca/shmem/base/base.h"
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#include "opal/mca/shmem/shmem.h"
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#include "shmem_posix.h"
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#include "shmem_posix_common_utils.h"
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/* ////////////////////////////////////////////////////////////////////////// */
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int
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shmem_posix_shm_open(char *posix_file_name_buff, size_t size)
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{
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int attempt = 0, fd = -1;
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/* workaround for simultaneous posix shm_opens on the same node (e.g.
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* multiple Open MPI jobs sharing a node). name collision during component
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* runtime will happen, so protect against it by trying a few times.
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*/
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do {
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/* format: /open_mpi.nnnn
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* see comment in shmem_posix.h that explains why we chose to do things
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* this way.
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*/
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snprintf(posix_file_name_buff, size, "%s%04d",
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OPAL_SHMEM_POSIX_FILE_NAME_PREFIX, attempt++);
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/* the check for the existence of the object and its creation if it
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* does not exist are performed atomically.
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*/
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if (-1 == (fd = shm_open(posix_file_name_buff,
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O_CREAT | O_EXCL | O_RDWR, 0600))) {
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int err = errno;
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/* the object already exists, so try again with a new name */
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if (EEXIST == err) {
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continue;
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}
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/* a "real" error occurred. fd is already set to -1, so get out
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* of here. we can't be selected :-(.
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*/
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else {
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char hn[MAXHOSTNAMELEN];
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gethostname(hn, MAXHOSTNAMELEN - 1);
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hn[MAXHOSTNAMELEN - 1] = '\0';
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opal_output_verbose(10, opal_shmem_base_framework.framework_output,
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"shmem_posix_shm_open: disqualifying posix because "
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"shm_open(2) failed with error: %s (errno %d)\n",
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strerror(err), err);
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break;
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}
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}
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/* we found an available file name */
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else {
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break;
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}
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} while (attempt < OPAL_SHMEM_POSIX_MAX_ATTEMPTS);
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/* if we didn't find a name, let the user know that we tried and failed */
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if (attempt >= OPAL_SHMEM_POSIX_MAX_ATTEMPTS) {
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opal_output(0, "shmem: posix: file name search - max attempts exceeded."
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"cannot continue with posix.\n");
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}
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return fd;
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}
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