* license is available at http://www.OpenLDAP.org/license.html or
* in file LICENSE in the top-level directory of the distribution.
*/
-/* File locking methods */
+
+/*
+ * 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>
-#if defined(NEED_FCNTL_LOCKING)
+#undef LOCK_API
+
+#if HAVE_LOCKF && defined(F_LOCK)
+# define USE_LOCKF 1
+# define LOCK_API "lockf"
+#endif
+
+#if !defined(LOCK_API) && 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) && HAVE_FLOCK
+# if 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_lockf ( FILE *fp ) {
+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;
- return( fcntl( fileno(fp), F_SETLKW, &file_lock ) );
+
+ /* use F_SETLKW instead of F_SETLK, ie: block */
+ return( fcntl( fd, F_SETLKW, &file_lock ) );
}
-int lutil_unlockf ( FILE *fp ) {
+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( fileno(fp), F_SETLK, &file_lock ) );
+
+ return( fcntl ( fd, F_SETLKW, &file_lock ) );
}
+#endif
-#endif /* !HAVE_FILE_LOCKING */
+#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