1/*- 2 * Copyright (c) 2007 Dag-Erling Co�dan Sm�rgrav 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer 10 * in this position and unchanged. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 */ 27 28#include <sys/cdefs.h>
| 1/*- 2 * Copyright (c) 2007 Dag-Erling Co�dan Sm�rgrav 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer 10 * in this position and unchanged. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 */ 27 28#include <sys/cdefs.h>
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37int 38flopen(const char *path, int flags, ...) 39{ 40 int fd, operation, serrno; 41 struct stat sb, fsb; 42 mode_t mode; 43 44#ifdef O_EXLOCK 45 flags &= ~O_EXLOCK; 46#endif 47 48 mode = 0; 49 if (flags & O_CREAT) { 50 va_list ap; 51 52 va_start(ap, flags); 53 mode = va_arg(ap, int); /* mode_t promoted to int */ 54 va_end(ap); 55 } 56 57 operation = LOCK_EX; 58 if (flags & O_NONBLOCK) 59 operation |= LOCK_NB; 60 61 for (;;) { 62 if ((fd = open(path, flags, mode)) == -1) 63 /* non-existent or no access */ 64 return (-1); 65 if (flock(fd, operation) == -1) { 66 /* unsupported or interrupted */ 67 serrno = errno; 68 close(fd); 69 errno = serrno; 70 return (-1); 71 } 72 if (stat(path, &sb) == -1) { 73 /* disappeared from under our feet */ 74 close(fd); 75 continue; 76 } 77 if (fstat(fd, &fsb) == -1) { 78 /* can't happen [tm] */ 79 serrno = errno; 80 close(fd); 81 errno = serrno; 82 return (-1); 83 } 84 if (sb.st_dev != fsb.st_dev || 85 sb.st_ino != fsb.st_ino) { 86 /* changed under our feet */ 87 close(fd); 88 continue; 89 } 90 return (fd); 91 } 92}
| 41int 42flopen(const char *path, int flags, ...) 43{ 44 int fd, operation, serrno; 45 struct stat sb, fsb; 46 mode_t mode; 47 48#ifdef O_EXLOCK 49 flags &= ~O_EXLOCK; 50#endif 51 52 mode = 0; 53 if (flags & O_CREAT) { 54 va_list ap; 55 56 va_start(ap, flags); 57 mode = va_arg(ap, int); /* mode_t promoted to int */ 58 va_end(ap); 59 } 60 61 operation = LOCK_EX; 62 if (flags & O_NONBLOCK) 63 operation |= LOCK_NB; 64 65 for (;;) { 66 if ((fd = open(path, flags, mode)) == -1) 67 /* non-existent or no access */ 68 return (-1); 69 if (flock(fd, operation) == -1) { 70 /* unsupported or interrupted */ 71 serrno = errno; 72 close(fd); 73 errno = serrno; 74 return (-1); 75 } 76 if (stat(path, &sb) == -1) { 77 /* disappeared from under our feet */ 78 close(fd); 79 continue; 80 } 81 if (fstat(fd, &fsb) == -1) { 82 /* can't happen [tm] */ 83 serrno = errno; 84 close(fd); 85 errno = serrno; 86 return (-1); 87 } 88 if (sb.st_dev != fsb.st_dev || 89 sb.st_ino != fsb.st_ino) { 90 /* changed under our feet */ 91 close(fd); 92 continue; 93 } 94 return (fd); 95 } 96}
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