diff options
Diffstat (limited to 'lib/libc/gen/lockf.c')
-rw-r--r-- | lib/libc/gen/lockf.c | 79 |
1 files changed, 79 insertions, 0 deletions
diff --git a/lib/libc/gen/lockf.c b/lib/libc/gen/lockf.c new file mode 100644 index 0000000..2c567ba --- /dev/null +++ b/lib/libc/gen/lockf.c @@ -0,0 +1,79 @@ +/* $NetBSD: lockf.c,v 1.3 2008/04/28 20:22:59 martin Exp $ */ +/*- + * Copyright (c) 1997 The NetBSD Foundation, Inc. + * All rights reserved. + * + * This code is derived from software contributed to The NetBSD Foundation + * by Klaus Klein. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS + * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED + * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR + * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS + * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + */ + +#include <sys/cdefs.h> +__FBSDID("$FreeBSD$"); + +#include "namespace.h" +#include <errno.h> +#include <fcntl.h> +#include <unistd.h> +#include "un-namespace.h" + +int +lockf(int filedes, int function, off_t size) +{ + struct flock fl; + int cmd; + + fl.l_start = 0; + fl.l_len = size; + fl.l_whence = SEEK_CUR; + + switch (function) { + case F_ULOCK: + cmd = F_SETLK; + fl.l_type = F_UNLCK; + break; + case F_LOCK: + cmd = F_SETLKW; + fl.l_type = F_WRLCK; + break; + case F_TLOCK: + cmd = F_SETLK; + fl.l_type = F_WRLCK; + break; + case F_TEST: + fl.l_type = F_WRLCK; + if (_fcntl(filedes, F_GETLK, &fl) == -1) + return (-1); + if (fl.l_type == F_UNLCK || (fl.l_sysid == 0 && fl.l_pid == getpid())) + return (0); + errno = EAGAIN; + return (-1); + /* NOTREACHED */ + default: + errno = EINVAL; + return (-1); + /* NOTREACHED */ + } + + return (_fcntl(filedes, cmd, &fl)); +} |