bsd/sys/lockf.h

   1 /*
   2  * Copyright (c) 2000-2002 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
   7  *
   8  * This file contains Original Code and/or Modifications of Original Code
   9  * as defined in and that are subject to the Apple Public Source License
  10  * Version 2.0 (the 'License'). You may not use this file except in
  11  * compliance with the License. Please obtain a copy of the License at
  12  * http://www.opensource.apple.com/apsl/ and read it before using this
  13  * file.
  14  *
  15  * The Original Code and all software distributed under the License are
  16  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  17  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  18  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  20  * Please see the License for the specific language governing rights and
  21  * limitations under the License.
  22  *
  23  * @APPLE_LICENSE_HEADER_END@
  24  */
  25 /* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
  26 /*
  27  * Copyright (c) 1991, 1993
  28  *      The Regents of the University of California.  All rights reserved.
  29  *
  30  * This code is derived from software contributed to Berkeley by
  31  * Scooter Morris at Genentech Inc.
  32  *
  33  * Redistribution and use in source and binary forms, with or without
  34  * modification, are permitted provided that the following conditions
  35  * are met:
  36  * 1. Redistributions of source code must retain the above copyright
  37  *    notice, this list of conditions and the following disclaimer.
  38  * 2. Redistributions in binary form must reproduce the above copyright
  39  *    notice, this list of conditions and the following disclaimer in the
  40  *    documentation and/or other materials provided with the distribution.
  41  * 3. All advertising materials mentioning features or use of this software
  42  *    must display the following acknowledgement:
  43  *      This product includes software developed by the University of
  44  *      California, Berkeley and its contributors.
  45  * 4. Neither the name of the University nor the names of its contributors
  46  *    may be used to endorse or promote products derived from this software
  47  *    without specific prior written permission.
  48  *
  49  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  50  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  51  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  52  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  53  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  54  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  55  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  56  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  57  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  58  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  59  * SUCH DAMAGE.
  60  *
  61  *      @(#)lockf.h     8.1 (Berkeley) 6/11/93
  62  */
  63
  64 #ifndef _SYS_LOCKF_H_
  65 #define _SYS_LOCKF_H_
  66
  67 #include <sys/appleapiopts.h>
  68 #include <sys/cdefs.h>
  69
  70 #ifdef __APPLE_API_PRIVATE
  71 /*
  72  * The lockf structure is a kernel structure which contains the information
  73  * associated with a byte range lock.  The lockf structures are linked into
  74  * the inode structure. Locks are sorted by the starting byte of the lock for
  75  * efficiency.
  76  */
  77 struct lockf {
  78         short   lf_flags;        /* Lock semantics: F_POSIX, F_FLOCK, F_WAIT */
  79         short   lf_type;         /* Lock type: F_RDLCK, F_WRLCK */
  80         off_t   lf_start;        /* The byte # of the start of the lock */
  81         off_t   lf_end;          /* The byte # of the end of the lock (-1=EOF)*/
  82         caddr_t lf_id;           /* The id of the resource holding the lock */
  83         struct  lockf **lf_head; /* Back pointer to the head of lockf list */
  84         struct  lockf *lf_next;  /* A pointer to the next lock on this inode */
  85         struct  lockf *lf_block; /* The list of blocked locks */
  86 };
  87
  88 /* Maximum length of sleep chains to traverse to try and detect deadlock. */
  89 #define MAXDEPTH 50
  90
  91 __BEGIN_DECLS
  92 void     lf_addblock __P((struct lockf *, struct lockf *));
  93 int      lf_advlock __P((struct lockf **,
  94             off_t, caddr_t, int, struct flock *, int));
  95 int      lf_clearlock __P((struct lockf *));
  96 int      lf_findoverlap __P((struct lockf *,
  97             struct lockf *, int, struct lockf ***, struct lockf **));
  98 struct lockf *
  99          lf_getblock __P((struct lockf *));
 100 int      lf_getlock __P((struct lockf *, struct flock *));
 101 int      lf_setlock __P((struct lockf *));
 102 void     lf_split __P((struct lockf *, struct lockf *));
 103 void     lf_wakelock __P((struct lockf *));
 104 __END_DECLS
 105
 106 #if LOCKF_DEBUG
 107 extern int lockf_debug;
 108
 109 __BEGIN_DECLS
 110 void    lf_print __P((char *, struct lockf *));
 111 void    lf_printlist __P((char *, struct lockf *));
 112 __END_DECLS
 113 #endif /* LOCKF_DEBUG */
 114
 115 #endif /* __APPLE_API_PRIVATE */
 116
 117 #endif /* !_SYS_LOCKF_H_ */