/* $NetBSD: lockf.c,v 1.1.1.6.6.1 2019/08/10 06:17:16 martin Exp $ */ /* $OpenLDAP$ */ /* This work is part of OpenLDAP Software . * * Copyright 1998-2019 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 * . */ /* * 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 __RCSID("$NetBSD: lockf.c,v 1.1.1.6.6.1 2019/08/10 06:17:16 martin Exp $"); #include "portable.h" #include #include #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 # 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 # 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