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 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