Annotation of src/lib/libc/gen/lockf.c, Revision 1.2
1.2 ! mycroft 1: /* $NetBSD: lockf.c,v 1.1 1997/12/20 20:23:18 kleink Exp $ */
1.1 kleink 2:
3: /*-
4: * Copyright (c) 1997 The NetBSD Foundation, Inc.
5: * All rights reserved.
6: *
7: * This code is derived from software contributed to The NetBSD Foundation
8: * by Klaus Klein.
9: *
10: * Redistribution and use in source and binary forms, with or without
11: * modification, are permitted provided that the following conditions
12: * are met:
13: * 1. Redistributions of source code must retain the above copyright
14: * notice, this list of conditions and the following disclaimer.
15: * 2. Redistributions in binary form must reproduce the above copyright
16: * notice, this list of conditions and the following disclaimer in the
17: * documentation and/or other materials provided with the distribution.
18: * 3. All advertising materials mentioning features or use of this software
19: * must display the following acknowledgement:
20: * This product includes software developed by the NetBSD
21: * Foundation, Inc. and its contributors.
22: * 4. Neither the name of The NetBSD Foundation nor the names of its
23: * contributors may be used to endorse or promote products derived
24: * from this software without specific prior written permission.
25: *
26: * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
27: * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28: * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29: * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
30: * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31: * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32: * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33: * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34: * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35: * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36: * POSSIBILITY OF SUCH DAMAGE.
37: */
38:
39: #include <sys/cdefs.h>
40: #if defined(LIBC_SCCS) && !defined(lint)
1.2 ! mycroft 41: __RCSID("$NetBSD: lockf.c,v 1.1 1997/12/20 20:23:18 kleink Exp $");
1.1 kleink 42: #endif
43:
44: #include "namespace.h"
45: #include <errno.h>
46: #include <fcntl.h>
47: #include <unistd.h>
48:
49: #ifdef __weak_alias
1.2 ! mycroft 50: __weak_alias(lockf,_lockf)
1.1 kleink 51: #endif
52:
53:
54: int
55: lockf(filedes, function, size)
56: int filedes;
57: int function;
58: off_t size;
59: {
60: struct flock fl;
61: int cmd;
62:
63: fl.l_start = 0;
64: fl.l_len = size;
65: fl.l_whence = SEEK_CUR;
66:
67: switch (function) {
68: case F_ULOCK:
69: cmd = F_SETLK;
70: fl.l_type = F_UNLCK;
71: break;
72: case F_LOCK:
73: cmd = F_SETLKW;
74: fl.l_type = F_WRLCK;
75: break;
76: case F_TLOCK:
77: cmd = F_SETLK;
78: fl.l_type = F_WRLCK;
79: break;
80: case F_TEST:
81: fl.l_type = F_WRLCK;
82: if (fcntl(filedes, F_GETLK, &fl) == -1)
83: return (-1);
84: if (fl.l_type == F_UNLCK || fl.l_pid == getpid())
85: return (0);
86: errno = EAGAIN;
87: return (-1);
88: /* NOTREACHED */
89: default:
90: errno = EINVAL;
91: return (-1);
92: /* NOTREACHED */
93: }
94:
95: return (fcntl(filedes, cmd, &fl));
96: }
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