/
flock.c
83 lines (78 loc) · 2.83 KB
/
flock.c
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
/*
* Program: Unix compatibility routines
*
* Author: Mark Crispin
* Networks and Distributed Computing
* Computing & Communications
* University of Washington
* Administration Building, AG-44
* Seattle, WA 98195
* Internet: MRC@CAC.Washington.EDU
*
* Date: 14 September 1996
* Last Edited: 14 August 1997
*
* Copyright 1997 by the University of Washington
*
* Permission to use, copy, modify, and distribute this software and its
* documentation for any purpose and without fee is hereby granted, provided
* that the above copyright notice appears in all copies and that both the
* above copyright notice and this permission notice appear in supporting
* documentation, and that the name of the University of Washington not be
* used in advertising or publicity pertaining to distribution of the software
* without specific, written prior permission. This software is made available
* "as is", and
* THE UNIVERSITY OF WASHINGTON DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED,
* WITH REGARD TO THIS SOFTWARE, INCLUDING WITHOUT LIMITATION ALL IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, AND IN
* NO EVENT SHALL THE UNIVERSITY OF WASHINGTON BE LIABLE FOR ANY SPECIAL,
* INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
* LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, TORT
* (INCLUDING NEGLIGENCE) OR STRICT LIABILITY, ARISING OUT OF OR IN CONNECTION
* WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*
*/
/* DEDICATION
* This file is dedicated to my dog, Unix, also known as Yun-chan and
* Unix J. Terwilliker Jehosophat Aloysius Monstrosity Animal Beast. Unix
* passed away at the age of 11 1/2 on September 14, 1996, 12:18 PM PDT, after
* a two-month bout with cirrhosis of the liver.
*
* He was a dear friend, and I miss him terribly.
*
* Lift a leg, Yunie. Luv ya forever!!!!
*/
#include <windows.h>
#include <io.h>
#include <errno.h>
#include "flock.h"
int flock(int fd, int op)
{
HANDLE hdl = (HANDLE) _get_osfhandle(fd);
DWORD low = 1, high = 0;
OVERLAPPED offset =
{0, 0, 0, 0, NULL};
if (hdl < 0)
return -1; /* error in file descriptor */
/* bug for bug compatible with Unix */
UnlockFileEx(hdl, 0, low, high, &offset);
switch (op & ~LOCK_NB) { /* translate to LockFileEx() op */
case LOCK_EX: /* exclusive */
if (LockFileEx(hdl, LOCKFILE_EXCLUSIVE_LOCK +
((op & LOCK_NB) ? LOCKFILE_FAIL_IMMEDIATELY : 0),
0, low, high, &offset))
return 0;
break;
case LOCK_SH: /* shared */
if (LockFileEx(hdl, ((op & LOCK_NB) ? LOCKFILE_FAIL_IMMEDIATELY : 0),
0, low, high, &offset))
return 0;
break;
case LOCK_UN: /* unlock */
return 0; /* always succeeds */
default: /* default */
break;
}
errno = EINVAL; /* bad call */
return -1;
}