1 /*
2 * Copyright (c) 1995, 1996, 1997 Kungliga Tekniska Högskolan
3 * (Royal Institute of Technology, Stockholm, Sweden).
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 *
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 *
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 *
17 * 3. Neither the name of the Institute nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34 #include <config.h>
35
36 #ifndef HAVE_FLOCK
37
38 #include "roken.h"
39
40 #define OP_MASK (LOCK_SH | LOCK_EX | LOCK_UN)
41
42
43 ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL
rk_flock(int fd,int operation)44 rk_flock(int fd, int operation)
45 {
46 #if defined(HAVE_FCNTL) && defined(F_SETLK)
47 struct flock arg;
48 int code, cmd;
49
50 arg.l_whence = SEEK_SET;
51 arg.l_start = 0;
52 arg.l_len = 0; /* means to EOF */
53
54 if (operation & LOCK_NB)
55 cmd = F_SETLK;
56 else
57 cmd = F_SETLKW; /* Blocking */
58
59 switch (operation & OP_MASK) {
60 case LOCK_UN:
61 arg.l_type = F_UNLCK;
62 code = fcntl(fd, F_SETLK, &arg);
63 break;
64 case LOCK_SH:
65 arg.l_type = F_RDLCK;
66 code = fcntl(fd, cmd, &arg);
67 break;
68 case LOCK_EX:
69 arg.l_type = F_WRLCK;
70 code = fcntl(fd, cmd, &arg);
71 break;
72 default:
73 errno = EINVAL;
74 code = -1;
75 break;
76 }
77 return code;
78
79 #elif defined(_WIN32)
80 /* Windows */
81
82 #define FLOCK_OFFSET_LOW 0
83 #define FLOCK_OFFSET_HIGH 0
84 #define FLOCK_LENGTH_LOW 0x00000000
85 #define FLOCK_LENGTH_HIGH 0x80000000
86
87 HANDLE hFile;
88 OVERLAPPED ov;
89 BOOL rv = FALSE;
90 DWORD f = 0;
91
92 hFile = (HANDLE) _get_osfhandle(fd);
93 if (hFile == NULL || hFile == INVALID_HANDLE_VALUE) {
94 _set_errno(EBADF);
95 return -1;
96 }
97
98 ZeroMemory(&ov, sizeof(ov));
99 ov.hEvent = NULL;
100 ov.Offset = FLOCK_OFFSET_LOW;
101 ov.OffsetHigh = FLOCK_OFFSET_HIGH;
102
103 if (operation & LOCK_NB)
104 f = LOCKFILE_FAIL_IMMEDIATELY;
105
106 switch (operation & OP_MASK) {
107 case LOCK_UN: /* Unlock */
108 rv = UnlockFileEx(hFile, 0,
109 FLOCK_LENGTH_LOW, FLOCK_LENGTH_HIGH, &ov);
110 break;
111
112 case LOCK_SH: /* Shared lock */
113 rv = LockFileEx(hFile, f, 0,
114 FLOCK_LENGTH_LOW, FLOCK_LENGTH_HIGH, &ov);
115 break;
116
117 case LOCK_EX: /* Exclusive lock */
118 rv = LockFileEx(hFile, f|LOCKFILE_EXCLUSIVE_LOCK, 0,
119 FLOCK_LENGTH_LOW, FLOCK_LENGTH_HIGH,
120 &ov);
121 break;
122
123 default:
124 _set_errno(EINVAL);
125 return -1;
126 }
127
128 if (!rv) {
129 switch (GetLastError()) {
130 case ERROR_SHARING_VIOLATION:
131 case ERROR_LOCK_VIOLATION:
132 case ERROR_IO_PENDING:
133 _set_errno(EWOULDBLOCK);
134 break;
135
136 case ERROR_ACCESS_DENIED:
137 _set_errno(EACCES);
138 break;
139
140 default:
141 _set_errno(ENOLCK);
142 }
143 return -1;
144 }
145
146 return 0;
147
148 #else
149 return -1;
150 #endif
151 }
152
153 #endif
154
155