/*
* Bacula Thread Read/Write locking code. It permits
- * multiple readers but only one writer.
+ * multiple readers but only one writer.
*
* Kern Sibbald, January MMI
*
* This code adapted from "Programming with POSIX Threads", by
* David R. Butenhof
*
+ * Version $Id$
+ *
*/
/*
- Copyright (C) 2000, 2001, 2002 Kern Sibbald and John Walker
+ Bacula® - The Network Backup Solution
+
+ Copyright (C) 2001-2006 Free Software Foundation Europe e.V.
- This program is free software; you can redistribute it and/or
- modify it under the terms of the GNU General Public License as
- published by the Free Software Foundation; either version 2 of
- the License, or (at your option) any later version.
+ The main author of Bacula is Kern Sibbald, with contributions from
+ many others, a complete list can be found in the file AUTHORS.
+ This program is Free Software; you can redistribute it and/or
+ modify it under the terms of version two of the GNU General Public
+ License as published by the Free Software Foundation and included
+ in the file LICENSE.
- This program is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
+ This program 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
General Public License for more details.
- You should have received a copy of the GNU General Public
- License along with this program; if not, write to the Free
- Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
- MA 02111-1307, USA.
+ You should have received a copy of the GNU General Public License
+ along with this program; if not, write to the Free Software
+ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ 02110-1301, USA.
- */
+ Bacula® is a registered trademark of Kern Sibbald.
+ The licensor of Bacula is the Free Software Foundation Europe
+ (FSFE), Fiduciary Program, Sumatrastrasse 25, 8006 Zürich,
+ Switzerland, email:ftf@fsfeurope.org.
+*/
-#ifndef __RWLOCK_H
+#ifndef __RWLOCK_H
#define __RWLOCK_H 1
-typedef struct rwlock_tag {
+typedef struct s_rwlock_tag {
pthread_mutex_t mutex;
pthread_cond_t read; /* wait for read */
pthread_cond_t write; /* wait for write */
+ pthread_t writer_id; /* writer's thread id */
int valid; /* set when valid */
int r_active; /* readers active */
int w_active; /* writers active */
int r_wait; /* readers waiting */
int w_wait; /* writers waiting */
-} rwlock_t;
+} brwlock_t;
+
+typedef struct s_rwsteal_tag {
+ pthread_t writer_id; /* writer's thread id */
+ int state;
+} brwsteal_t;
+
#define RWLOCK_VALID 0xfacade
{PTHREAD_MUTEX_INITIALIZER, PTHREAD_COND_INITIALIZER, \
PTHREAD_COND_INITIALIZER, RWLOCK_VALID, 0, 0, 0, 0}
-/*
+/*
* read/write lock prototypes
*/
-extern int rwl_init(rwlock_t *wrlock);
-extern int rwl_destroy(rwlock_t *rwlock);
-extern int rwl_readlock(rwlock_t *rwlock);
-extern int rwl_readtrylock(rwlock_t *rwlock);
-extern int rwl_readunlock(rwlock_t *rwlock);
-extern int rwl_writelock(rwlock_t *rwlock);
-extern int rwl_writetrylock(rwlock_t *rwlock);
-extern int rwl_writeunlock(rwlock_t *rwlock);
+extern int rwl_init(brwlock_t *wrlock);
+extern int rwl_destroy(brwlock_t *rwlock);
+extern int rwl_readlock(brwlock_t *rwlock);
+extern int rwl_readtrylock(brwlock_t *rwlock);
+extern int rwl_readunlock(brwlock_t *rwlock);
+extern int rwl_writelock(brwlock_t *rwlock);
+extern int rwl_writetrylock(brwlock_t *rwlock);
+extern int rwl_writeunlock(brwlock_t *rwlock);
#endif /* __RWLOCK_H */