diff options
author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 11:11:40 +0000 |
---|---|---|
committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 11:11:40 +0000 |
commit | 7731832751ab9f3c6ddeb66f186d3d7fa1934a6d (patch) | |
tree | e91015872543a59be2aad26c2fea02e41b57005d /libraries/liblutil/lockf.c | |
parent | Initial commit. (diff) | |
download | openldap-upstream/2.4.57+dfsg.tar.xz openldap-upstream/2.4.57+dfsg.zip |
Adding upstream version 2.4.57+dfsg.upstream/2.4.57+dfsgupstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | libraries/liblutil/lockf.c | 118 |
1 files changed, 118 insertions, 0 deletions
diff --git a/libraries/liblutil/lockf.c b/libraries/liblutil/lockf.c new file mode 100644 index 0000000..8bdb1fe --- /dev/null +++ b/libraries/liblutil/lockf.c @@ -0,0 +1,118 @@ +/* $OpenLDAP$ */ +/* This work is part of OpenLDAP Software <http://www.openldap.org/>. + * + * Copyright 1998-2021 The OpenLDAP Foundation. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted only as authorized by the OpenLDAP + * Public License. + * + * A copy of this license is available in the file LICENSE in the + * top-level directory of the distribution or, alternatively, at + * <http://www.OpenLDAP.org/license.html>. + */ + +/* + * File Locking Routines + * + * Implementations (in order of preference) + * - lockf + * - fcntl + * - flock + * + * Other implementations will be added as needed. + * + * NOTE: lutil_lockf() MUST block until an exclusive lock is acquired. + */ + +#include "portable.h" + +#include <stdio.h> +#include <ac/unistd.h> + +#undef LOCK_API + +#if defined(HAVE_LOCKF) && defined(F_LOCK) +# define USE_LOCKF 1 +# define LOCK_API "lockf" +#endif + +#if !defined(LOCK_API) && defined(HAVE_FCNTL) +# ifdef HAVE_FCNTL_H +# include <fcntl.h> +# endif +# ifdef F_WRLCK +# define USE_FCNTL 1 +# define LOCK_API "fcntl" +# endif +#endif + +#if !defined(LOCK_API) && defined(HAVE_FLOCK) +# ifdef HAVE_SYS_FILE_H +# include <sys/file.h> +# endif +# define USE_FLOCK 1 +# define LOCK_API "flock" +#endif + +#if !defined(USE_LOCKF) && !defined(USE_FCNTL) && !defined(USE_FLOCK) +int lutil_lockf ( int fd ) { + fd = fd; + return 0; +} + +int lutil_unlockf ( int fd ) { + fd = fd; + return 0; +} +#endif + +#ifdef USE_LOCKF +int lutil_lockf ( int fd ) { + /* use F_LOCK instead of F_TLOCK, ie: block */ + return lockf( fd, F_LOCK, 0 ); +} + +int lutil_unlockf ( int fd ) { + return lockf( fd, F_ULOCK, 0 ); +} +#endif + +#ifdef USE_FCNTL +int lutil_lockf ( int fd ) { + struct flock file_lock; + + memset( &file_lock, '\0', sizeof( file_lock ) ); + file_lock.l_type = F_WRLCK; + file_lock.l_whence = SEEK_SET; + file_lock.l_start = 0; + file_lock.l_len = 0; + + /* use F_SETLKW instead of F_SETLK, ie: block */ + return( fcntl( fd, F_SETLKW, &file_lock ) ); +} + +int lutil_unlockf ( int fd ) { + struct flock file_lock; + + memset( &file_lock, '\0', sizeof( file_lock ) ); + file_lock.l_type = F_UNLCK; + file_lock.l_whence = SEEK_SET; + file_lock.l_start = 0; + file_lock.l_len = 0; + + return( fcntl ( fd, F_SETLKW, &file_lock ) ); +} +#endif + +#ifdef USE_FLOCK +int lutil_lockf ( int fd ) { + /* use LOCK_EX instead of LOCK_EX|LOCK_NB, ie: block */ + return flock( fd, LOCK_EX ); +} + +int lutil_unlockf ( int fd ) { + return flock( fd, LOCK_UN ); +} +#endif |