bsd/sys/lockf.h

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22 /* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
  23 /*
  24  * Copyright (c) 1991, 1993
  25  *      The Regents of the University of California.  All rights reserved.
  26  *
  27  * This code is derived from software contributed to Berkeley by
  28  * Scooter Morris at Genentech Inc.
  29  *
  30  * Redistribution and use in source and binary forms, with or without
  31  * modification, are permitted provided that the following conditions
  32  * are met:
  33  * 1. Redistributions of source code must retain the above copyright
  34  *    notice, this list of conditions and the following disclaimer.
  35  * 2. Redistributions in binary form must reproduce the above copyright
  36  *    notice, this list of conditions and the following disclaimer in the
  37  *    documentation and/or other materials provided with the distribution.
  38  * 3. All advertising materials mentioning features or use of this software
  39  *    must display the following acknowledgement:
  40  *      This product includes software developed by the University of
  41  *      California, Berkeley and its contributors.
  42  * 4. Neither the name of the University nor the names of its contributors
  43  *    may be used to endorse or promote products derived from this software
  44  *    without specific prior written permission.
  45  *
  46  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  47  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  48  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  49  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  50  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  51  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  52  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  53  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  54  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  55  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  56  * SUCH DAMAGE.
  57  *
  58  *      @(#)lockf.h     8.1 (Berkeley) 6/11/93
  59  */
  60
  61 #ifndef _SYS_LOCKF_H_
  62 #define _SYS_LOCKF_H_
  63
  64 /*
  65  * The lockf structure is a kernel structure which contains the information
  66  * associated with a byte range lock.  The lockf structures are linked into
  67  * the inode structure. Locks are sorted by the starting byte of the lock for
  68  * efficiency.
  69  */
  70 struct lockf {
  71         short   lf_flags;        /* Lock semantics: F_POSIX, F_FLOCK, F_WAIT */
  72         short   lf_type;         /* Lock type: F_RDLCK, F_WRLCK */
  73         off_t   lf_start;        /* The byte # of the start of the lock */
  74         off_t   lf_end;          /* The byte # of the end of the lock (-1=EOF)*/
  75         caddr_t lf_id;           /* The id of the resource holding the lock */
  76         struct  lockf **lf_head; /* Back pointer to the head of lockf list */
  77         struct  lockf *lf_next;  /* A pointer to the next lock on this inode */
  78         struct  lockf *lf_block; /* The list of blocked locks */
  79 };
  80
  81 /* Maximum length of sleep chains to traverse to try and detect deadlock. */
  82 #define MAXDEPTH 50
  83
  84 __BEGIN_DECLS
  85 void     lf_addblock __P((struct lockf *, struct lockf *));
  86 int      lf_advlock __P((struct lockf **,
  87             off_t, caddr_t, int, struct flock *, int));
  88 int      lf_clearlock __P((struct lockf *));
  89 int      lf_findoverlap __P((struct lockf *,
  90             struct lockf *, int, struct lockf ***, struct lockf **));
  91 struct lockf *
  92          lf_getblock __P((struct lockf *));
  93 int      lf_getlock __P((struct lockf *, struct flock *));
  94 int      lf_setlock __P((struct lockf *));
  95 void     lf_split __P((struct lockf *, struct lockf *));
  96 void     lf_wakelock __P((struct lockf *));
  97 __END_DECLS
  98
  99 #if LOCKF_DEBUG
 100 extern int lockf_debug;
 101
 102 __BEGIN_DECLS
 103 void    lf_print __P((char *, struct lockf *));
 104 void    lf_printlist __P((char *, struct lockf *));
 105 __END_DECLS
 106 #endif /* LOCKF_DEBUG */
 107 #endif /* !_SYS_LOCKF_H_ */