2006-01-08 08:21:40 +00:00
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/* Copyright (C) 1994,1996,1997,1998,1999,2000,2003,2006
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Free Software Foundation, Inc.
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2000-08-12 08:39:46 +00:00
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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2001-07-06 04:58:11 +00:00
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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2000-08-12 08:39:46 +00:00
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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2001-07-06 04:58:11 +00:00
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Lesser General Public License for more details.
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2000-08-12 08:39:46 +00:00
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2001-07-06 04:58:11 +00:00
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, write to the Free
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Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
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02111-1307 USA. */
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2000-08-12 08:39:46 +00:00
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#include <sys/types.h>
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#include <unistd.h>
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#include <fcntl.h>
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#include <errno.h>
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#include <string.h>
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#include <sysdep.h>
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2006-01-08 08:21:40 +00:00
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#include <kernel-features.h>
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2000-08-12 08:39:46 +00:00
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/* lockf is a simplified interface to fcntl's locking facilities. */
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#ifdef __NR_fcntl64
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# if __ASSUME_FCNTL64 == 0
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/* This variable is shared with all files that check for fcntl64. The
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declaration is in fcntl.c. */
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extern int __have_no_fcntl64;
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# endif
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#endif
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int
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lockf64 (int fd, int cmd, off64_t len64)
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{
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#if __ASSUME_FCNTL64 == 0
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struct flock fl;
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off_t len = (off_t) len64;
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#endif
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#ifdef __NR_fcntl64
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struct flock64 fl64;
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int cmd64;
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#endif
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#if __ASSUME_FCNTL64 == 0
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memset ((char *) &fl, '\0', sizeof (fl));
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/* lockf is always relative to the current file position. */
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fl.l_whence = SEEK_CUR;
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fl.l_start = 0;
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fl.l_len = len;
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#endif
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#ifdef __NR_fcntl64
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# if __ASSUME_FCNTL64 == 0
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if (!__have_no_fcntl64)
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{
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# endif
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memset ((char *) &fl64, '\0', sizeof (fl64));
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fl64.l_whence = SEEK_CUR;
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fl64.l_start = 0;
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fl64.l_len = len64;
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# if __ASSUME_FCNTL64 == 0
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}
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# endif
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#endif
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#if __ASSUME_FCNTL64 == 0 && !defined __NR_fcntl64
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if (len64 != (off64_t) len)
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{
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/* We can't represent the length. */
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__set_errno (EOVERFLOW);
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return -1;
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}
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#endif
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switch (cmd)
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{
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case F_TEST:
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/* Test the lock: return 0 if FD is unlocked or locked by this process;
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return -1, set errno to EACCES, if another process holds the lock. */
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#if __ASSUME_FCNTL64 > 0
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2000-10-30 06:47:34 +00:00
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fl64.l_type = F_RDLCK;
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2000-08-12 08:39:46 +00:00
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if (INLINE_SYSCALL (fcntl64, 3, fd, F_GETLK64, &fl64) < 0)
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return -1;
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if (fl64.l_type == F_UNLCK || fl64.l_pid == __getpid ())
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return 0;
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__set_errno (EACCES);
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return -1;
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#else
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# ifdef __NR_fcntl64
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if (!__have_no_fcntl64)
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{
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2000-10-30 06:47:34 +00:00
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int res;
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2000-08-12 08:39:46 +00:00
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2000-10-30 06:47:34 +00:00
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fl64.l_type = F_RDLCK;
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res = INLINE_SYSCALL (fcntl64, 3, fd, F_GETLK64, &fl64);
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2000-08-12 08:39:46 +00:00
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/* If errno == ENOSYS try the 32bit interface if len64 can
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be represented with 32 bits. */
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if (res == 0)
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{
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if (fl64.l_type == F_UNLCK || fl64.l_pid == __getpid ())
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return 0;
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__set_errno (EACCES);
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return -1;
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}
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else if (errno == ENOSYS)
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__have_no_fcntl64 = 1;
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else
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/* res < 0 && errno != ENOSYS. */
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return -1;
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if (len64 != (off64_t) len)
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{
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/* We can't represent the length. */
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__set_errno (EOVERFLOW);
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return -1;
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}
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}
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# endif
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2000-10-30 06:47:34 +00:00
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fl.l_type = F_RDLCK;
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2000-08-12 08:39:46 +00:00
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if (__fcntl (fd, F_GETLK, &fl) < 0)
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return -1;
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if (fl.l_type == F_UNLCK || fl.l_pid == __getpid ())
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return 0;
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__set_errno (EACCES);
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return -1;
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#endif
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case F_ULOCK:
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#if __ASSUME_FCNTL64 == 0
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fl.l_type = F_UNLCK;
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cmd = F_SETLK;
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#endif
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#ifdef __NR_fcntl64
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fl64.l_type = F_UNLCK;
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cmd64 = F_SETLK64;
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#endif
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break;
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case F_LOCK:
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#if __ASSUME_FCNTL64 == 0
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fl.l_type = F_WRLCK;
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cmd = F_SETLKW;
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#endif
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#ifdef __NR_fcntl64
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fl64.l_type = F_WRLCK;
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cmd64 = F_SETLKW64;
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#endif
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break;
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case F_TLOCK:
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#if __ASSUME_FCNTL64 == 0
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fl.l_type = F_WRLCK;
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cmd = F_SETLK;
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#endif
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#ifdef __NR_fcntl64
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fl64.l_type = F_WRLCK;
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cmd64 = F_SETLK64;
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#endif
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break;
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default:
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__set_errno (EINVAL);
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return -1;
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}
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#if __ASSUME_FCNTL64 > 0
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return INLINE_SYSCALL (fcntl64, 3, fd, cmd64, &fl64);
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#else
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# ifdef __NR_fcntl64
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if (!__have_no_fcntl64)
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{
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int res = INLINE_SYSCALL (fcntl64, 3, fd, cmd64, &fl64);
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/* If errno == ENOSYS try the 32bit interface if len64 can
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be represented with 32 bits. */
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if (res == 0 || errno != ENOSYS)
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return res;
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__have_no_fcntl64 = 1;
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if (len64 != (off64_t) len)
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{
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/* We can't represent the length. */
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__set_errno (EOVERFLOW);
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return -1;
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}
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}
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# endif
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return __fcntl (fd, cmd, &fl);
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#endif
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}
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