diff options
author | Jakub Jelinek <jakub@redhat.com> | 2007-07-12 18:26:36 +0000 |
---|---|---|
committer | Jakub Jelinek <jakub@redhat.com> | 2007-07-12 18:26:36 +0000 |
commit | 0ecb606cb6cf65de1d9fc8a919bceb4be476c602 (patch) | |
tree | 2ea1f8305970753e4a657acb2ccc15ca3eec8e2c /io/lockf64.c | |
parent | 7d58530341304d403a6626d7f7a1913165fe2f32 (diff) | |
download | glibc-0ecb606cb6cf65de1d9fc8a919bceb4be476c602.zip glibc-0ecb606cb6cf65de1d9fc8a919bceb4be476c602.tar.gz glibc-0ecb606cb6cf65de1d9fc8a919bceb4be476c602.tar.bz2 |
2.5-18.1
Diffstat (limited to 'io/lockf64.c')
-rw-r--r-- | io/lockf64.c | 79 |
1 files changed, 79 insertions, 0 deletions
diff --git a/io/lockf64.c b/io/lockf64.c new file mode 100644 index 0000000..e3b110c --- /dev/null +++ b/io/lockf64.c @@ -0,0 +1,79 @@ +/* Copyright (C) 1994,96,97,98,99,2000 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, write to the Free + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + 02111-1307 USA. */ + +#include <sys/types.h> +#include <unistd.h> +#include <fcntl.h> +#include <errno.h> +#include <string.h> + +/* lockf is a simplified interface to fcntl's locking facilities. */ + +int +lockf64 (int fd, int cmd, off64_t len64) +{ + struct flock fl; + off_t len = (off_t) len64; + + if (len64 != (off64_t) len) + { + /* We can't represent the length. */ + __set_errno (EOVERFLOW); + return -1; + } + + memset ((char *) &fl, '\0', sizeof (fl)); + + /* lockf is always relative to the current file position. */ + fl.l_whence = SEEK_CUR; + fl.l_start = 0; + fl.l_len = len; + + switch (cmd) + { + case F_TEST: + /* Test the lock: return 0 if FD is unlocked or locked by this process; + return -1, set errno to EACCES, if another process holds the lock. */ + fl.l_type = F_RDLCK; + if (__fcntl (fd, F_GETLK, &fl) < 0) + return -1; + if (fl.l_type == F_UNLCK || fl.l_pid == __getpid ()) + return 0; + __set_errno (EACCES); + return -1; + + case F_ULOCK: + fl.l_type = F_UNLCK; + cmd = F_SETLK; + break; + case F_LOCK: + fl.l_type = F_WRLCK; + cmd = F_SETLKW; + break; + case F_TLOCK: + fl.l_type = F_WRLCK; + cmd = F_SETLK; + break; + + default: + __set_errno (EINVAL); + return -1; + } + + return __fcntl (fd, cmd, &fl); +} |