16604ab260
shared memory objects are regular files; the shm_open(3) routine uses fcntl(2) to set a flag on the descriptor which tells mmap(2) to automatically apply MAP_NOSYNC. Not objected to by: bde, dillon, dufault, jasone
209 lines
7.4 KiB
C
209 lines
7.4 KiB
C
/*-
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* Copyright (c) 1983, 1990, 1993
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* The Regents of the University of California. All rights reserved.
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* (c) UNIX System Laboratories, Inc.
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* All or some portions of this file are derived from material licensed
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* to the University of California by American Telephone and Telegraph
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* Co. or Unix System Laboratories, Inc. and are reproduced herein with
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* the permission of UNIX System Laboratories, Inc.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the University of
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* California, Berkeley and its contributors.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* @(#)fcntl.h 8.3 (Berkeley) 1/21/94
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* $FreeBSD$
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*/
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#ifndef _SYS_FCNTL_H_
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#define _SYS_FCNTL_H_
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/*
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* This file includes the definitions for open and fcntl
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* described by POSIX for <fcntl.h>; it also includes
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* related kernel definitions.
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*/
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#ifndef _KERNEL
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#include <sys/types.h>
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#endif
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/*
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* File status flags: these are used by open(2), fcntl(2).
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* They are also used (indirectly) in the kernel file structure f_flags,
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* which is a superset of the open/fcntl flags. Open flags and f_flags
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* are inter-convertible using OFLAGS(fflags) and FFLAGS(oflags).
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* Open/fcntl flags begin with O_; kernel-internal flags begin with F.
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*/
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/* open-only flags */
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#define O_RDONLY 0x0000 /* open for reading only */
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#define O_WRONLY 0x0001 /* open for writing only */
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#define O_RDWR 0x0002 /* open for reading and writing */
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#define O_ACCMODE 0x0003 /* mask for above modes */
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/*
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* Kernel encoding of open mode; separate read and write bits that are
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* independently testable: 1 greater than the above.
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*
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* XXX
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* FREAD and FWRITE are excluded from the #ifdef _KERNEL so that TIOCFLUSH,
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* which was documented to use FREAD/FWRITE, continues to work.
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*/
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#ifndef _POSIX_SOURCE
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#define FREAD 0x0001
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#define FWRITE 0x0002
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#endif
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#define O_NONBLOCK 0x0004 /* no delay */
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#define O_APPEND 0x0008 /* set append mode */
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#ifndef _POSIX_SOURCE
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#define O_SHLOCK 0x0010 /* open with shared file lock */
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#define O_EXLOCK 0x0020 /* open with exclusive file lock */
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#define O_ASYNC 0x0040 /* signal pgrp when data ready */
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#define O_FSYNC 0x0080 /* synchronous writes */
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#define O_NOFOLLOW 0x0100 /* don't follow symlinks */
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#endif
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#define O_CREAT 0x0200 /* create if nonexistent */
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#define O_TRUNC 0x0400 /* truncate to zero length */
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#define O_EXCL 0x0800 /* error if already exists */
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#ifdef _KERNEL
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#define FMARK 0x1000 /* mark during gc() */
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#define FDEFER 0x2000 /* defer for next gc pass */
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#define FHASLOCK 0x4000 /* descriptor holds advisory lock */
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#endif
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/* Defined by POSIX 1003.1; BSD default, but must be distinct from O_RDONLY. */
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#define O_NOCTTY 0x8000 /* don't assign controlling terminal */
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#ifdef _KERNEL
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/* convert from open() flags to/from fflags; convert O_RD/WR to FREAD/FWRITE */
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#define FFLAGS(oflags) ((oflags) + 1)
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#define OFLAGS(fflags) ((fflags) - 1)
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/* bits to save after open */
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#define FMASK (FREAD|FWRITE|FAPPEND|FASYNC|FFSYNC|FNONBLOCK)
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/* bits settable by fcntl(F_SETFL, ...) */
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#define FCNTLFLAGS (FAPPEND|FASYNC|FFSYNC|FNONBLOCK|FPOSIXSHM)
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#endif
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/*
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* The O_* flags used to have only F* names, which were used in the kernel
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* and by fcntl. We retain the F* names for the kernel f_flag field
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* and for backward compatibility for fcntl.
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*/
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#ifndef _POSIX_SOURCE
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#define FAPPEND O_APPEND /* kernel/compat */
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#define FASYNC O_ASYNC /* kernel/compat */
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#define FFSYNC O_FSYNC /* kernel */
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#define FNONBLOCK O_NONBLOCK /* kernel */
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#define FNDELAY O_NONBLOCK /* compat */
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#define O_NDELAY O_NONBLOCK /* compat */
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#endif
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/*
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* We are out of bits in f_flag (which is a short). However,
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* the flag bits not set in FMASK are only meaningful in the
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* initial open syscall. Those bits can thus be given a
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* different meaning for fcntl(2).
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*/
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#ifndef _POSIX_SOURCE
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/*
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* Set by shm_open(3) to get automatic MAP_ASYNC behavior
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* for POSIX shared memory objects (which are otherwise
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* implemented as plain files).
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*/
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#define FPOSIXSHM O_NOFOLLOW
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#endif
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/*
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* Constants used for fcntl(2)
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*/
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/* command values */
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#define F_DUPFD 0 /* duplicate file descriptor */
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#define F_GETFD 1 /* get file descriptor flags */
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#define F_SETFD 2 /* set file descriptor flags */
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#define F_GETFL 3 /* get file status flags */
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#define F_SETFL 4 /* set file status flags */
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#ifndef _POSIX_SOURCE
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#define F_GETOWN 5 /* get SIGIO/SIGURG proc/pgrp */
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#define F_SETOWN 6 /* set SIGIO/SIGURG proc/pgrp */
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#endif
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#define F_GETLK 7 /* get record locking information */
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#define F_SETLK 8 /* set record locking information */
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#define F_SETLKW 9 /* F_SETLK; wait if blocked */
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/* file descriptor flags (F_GETFD, F_SETFD) */
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#define FD_CLOEXEC 1 /* close-on-exec flag */
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/* record locking flags (F_GETLK, F_SETLK, F_SETLKW) */
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#define F_RDLCK 1 /* shared or read lock */
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#define F_UNLCK 2 /* unlock */
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#define F_WRLCK 3 /* exclusive or write lock */
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#ifdef _KERNEL
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#define F_WAIT 0x010 /* Wait until lock is granted */
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#define F_FLOCK 0x020 /* Use flock(2) semantics for lock */
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#define F_POSIX 0x040 /* Use POSIX semantics for lock */
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#endif
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/*
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* Advisory file segment locking data type -
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* information passed to system by user
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*/
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struct flock {
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off_t l_start; /* starting offset */
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off_t l_len; /* len = 0 means until end of file */
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pid_t l_pid; /* lock owner */
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short l_type; /* lock type: read/write, etc. */
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short l_whence; /* type of l_start */
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};
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#ifndef _POSIX_SOURCE
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/* lock operations for flock(2) */
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#define LOCK_SH 0x01 /* shared file lock */
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#define LOCK_EX 0x02 /* exclusive file lock */
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#define LOCK_NB 0x04 /* don't block when locking */
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#define LOCK_UN 0x08 /* unlock file */
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#endif
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#ifndef _KERNEL
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#include <sys/cdefs.h>
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__BEGIN_DECLS
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int open __P((const char *, int, ...));
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int creat __P((const char *, mode_t));
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int fcntl __P((int, int, ...));
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#ifndef _POSIX_SOURCE
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int flock __P((int, int));
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#endif /* !_POSIX_SOURCE */
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__END_DECLS
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#endif
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#endif /* !_SYS_FCNTL_H_ */
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