4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 only,
8 * as published by the Free Software Foundation.
10 * This program is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * General Public License version 2 for more details (a copy is included
14 * in the LICENSE file that accompanied this code).
16 * You should have received a copy of the GNU General Public License
17 * version 2 along with this program; If not, see
18 * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
20 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
21 * CA 95054 USA or visit www.sun.com if you need additional information or
27 * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
28 * Use is subject to license terms.
31 * This file is part of Lustre, http://www.lustre.org/
32 * Lustre is a trademark of Sun Microsystems, Inc.
34 * libcfs/include/libcfs/user-lock.h
36 * Author: Nikita Danilov <nikita@clusterfs.com>
39 #ifndef __LIBCFS_USER_LOCK_H__
40 #define __LIBCFS_USER_LOCK_H__
42 #ifndef __LIBCFS_LIBCFS_H__
43 #error Do not #include this file directly. #include <libcfs/libcfs.h> instead
46 /* Implementations of portable synchronization APIs for liblustre */
49 * liblustre is single-threaded, so most "synchronization" APIs are trivial.
51 * XXX Liang: There are several branches share lnet with b_hd_newconfig,
52 * if we define lock APIs at here, there will be conflict with liblustre
59 * The userspace implementations of linux/spinlock.h vary; we just
60 * include our own for all of them
62 #define __LINUX_SPINLOCK_H
65 * Optional debugging (magic stamping and checking ownership) can be added.
71 * - cfs_spin_lock_init(x)
73 * - cfs_spin_unlock(x)
74 * - cfs_spin_trylock(x)
75 * - cfs_spin_lock_bh_init(x)
76 * - cfs_spin_lock_bh(x)
77 * - cfs_spin_unlock_bh(x)
79 * - cfs_spin_is_locked(x)
80 * - cfs_spin_lock_irqsave(x, f)
81 * - cfs_spin_unlock_irqrestore(x, f)
83 * No-op implementation.
85 struct cfs_spin_lock {int foo;};
87 typedef struct cfs_spin_lock cfs_spinlock_t;
89 #define CFS_SPIN_LOCK_UNLOCKED (cfs_spinlock_t) { }
90 #define LASSERT_SPIN_LOCKED(lock) do {(void)sizeof(lock);} while(0)
91 #define LINVRNT_SPIN_LOCKED(lock) do {(void)sizeof(lock);} while(0)
92 #define LASSERT_SEM_LOCKED(sem) do {(void)sizeof(sem);} while(0)
93 #define LASSERT_MUTEX_LOCKED(x) do {(void)sizeof(x);} while(0)
95 void cfs_spin_lock_init(cfs_spinlock_t *lock);
96 void cfs_spin_lock(cfs_spinlock_t *lock);
97 void cfs_spin_unlock(cfs_spinlock_t *lock);
98 int cfs_spin_trylock(cfs_spinlock_t *lock);
99 void cfs_spin_lock_bh_init(cfs_spinlock_t *lock);
100 void cfs_spin_lock_bh(cfs_spinlock_t *lock);
101 void cfs_spin_unlock_bh(cfs_spinlock_t *lock);
103 static inline int cfs_spin_is_locked(cfs_spinlock_t *l) {return 1;}
104 static inline void cfs_spin_lock_irqsave(cfs_spinlock_t *l, unsigned long f){}
105 static inline void cfs_spin_unlock_irqrestore(cfs_spinlock_t *l,
111 * - cfs_sema_init(x, v)
115 typedef struct cfs_semaphore {
119 void cfs_sema_init(cfs_semaphore_t *s, int val);
120 void __up(cfs_semaphore_t *s);
121 void __down(cfs_semaphore_t *s);
122 int __down_interruptible(cfs_semaphore_t *s);
124 #define CFS_DEFINE_SEMAPHORE(name) cfs_semaphore_t name = { 1 }
126 #define cfs_up(s) __up(s)
127 #define cfs_down(s) __down(s)
128 #define cfs_down_interruptible(s) __down_interruptible(s)
130 static inline int cfs_down_trylock(cfs_semaphore_t *sem)
138 * - cfs_init_completion_module(c)
139 * - cfs_call_wait_handler(t)
140 * - cfs_init_completion(c)
142 * - cfs_wait_for_completion(c)
143 * - cfs_wait_for_completion_interruptible(c)
150 typedef int (*cfs_wait_handler_t) (int timeout);
151 void cfs_init_completion_module(cfs_wait_handler_t handler);
152 int cfs_call_wait_handler(int timeout);
153 void cfs_init_completion(cfs_completion_t *c);
154 void cfs_complete(cfs_completion_t *c);
155 void cfs_wait_for_completion(cfs_completion_t *c);
156 int cfs_wait_for_completion_interruptible(cfs_completion_t *c);
158 #define CFS_COMPLETION_INITIALIZER(work) \
159 { 0, __WAIT_QUEUE_HEAD_INITIALIZER((work).wait) }
161 #define CFS_DECLARE_COMPLETION(work) \
162 cfs_completion_t work = CFS_COMPLETION_INITIALIZER(work)
164 #define CFS_INIT_COMPLETION(x) ((x).done = 0)
170 * - cfs_init_rwsem(x)
172 * - cfs_down_read_trylock(x)
173 * - cfs_down_write(struct cfs_rw_semaphore *s);
174 * - cfs_down_write_trylock(struct cfs_rw_semaphore *s);
177 * - cfs_fini_rwsem(x)
179 typedef struct cfs_rw_semaphore {
181 } cfs_rw_semaphore_t;
183 void cfs_init_rwsem(cfs_rw_semaphore_t *s);
184 void cfs_down_read(cfs_rw_semaphore_t *s);
185 int cfs_down_read_trylock(cfs_rw_semaphore_t *s);
186 void cfs_down_write(cfs_rw_semaphore_t *s);
187 int cfs_down_write_trylock(cfs_rw_semaphore_t *s);
188 void cfs_up_read(cfs_rw_semaphore_t *s);
189 void cfs_up_write(cfs_rw_semaphore_t *s);
190 void cfs_fini_rwsem(cfs_rw_semaphore_t *s);
191 #define CFS_DECLARE_RWSEM(name) cfs_rw_semaphore_t name = { }
194 * read-write lock : Need to be investigated more!!
195 * XXX nikita: for now, let rwlock_t to be identical to rw_semaphore
197 * - cfs_rwlock_init(x)
199 * - cfs_read_unlock(x)
200 * - cfs_write_lock(x)
201 * - cfs_write_unlock(x)
202 * - cfs_write_lock_irqsave(x)
203 * - cfs_write_unlock_irqrestore(x)
204 * - cfs_read_lock_irqsave(x)
205 * - cfs_read_unlock_irqrestore(x)
207 typedef cfs_rw_semaphore_t cfs_rwlock_t;
208 #define CFS_RW_LOCK_UNLOCKED (cfs_rwlock_t) { }
210 #define cfs_rwlock_init(pl) cfs_init_rwsem(pl)
212 #define cfs_read_lock(l) cfs_down_read(l)
213 #define cfs_read_unlock(l) cfs_up_read(l)
214 #define cfs_write_lock(l) cfs_down_write(l)
215 #define cfs_write_unlock(l) cfs_up_write(l)
218 cfs_write_lock_irqsave(cfs_rwlock_t *l, unsigned long f) { cfs_write_lock(l); }
220 cfs_write_unlock_irqrestore(cfs_rwlock_t *l, unsigned long f) { cfs_write_unlock(l); }
223 cfs_read_lock_irqsave(cfs_rwlock_t *l, unsigned long f) { cfs_read_lock(l); }
225 cfs_read_unlock_irqrestore(cfs_rwlock_t *l, unsigned long f) { cfs_read_unlock(l); }
228 * Atomic for single-threaded user-space
230 typedef struct { volatile int counter; } cfs_atomic_t;
232 #define CFS_ATOMIC_INIT(i) { (i) }
234 #define cfs_atomic_read(a) ((a)->counter)
235 #define cfs_atomic_set(a,b) do {(a)->counter = b; } while (0)
236 #define cfs_atomic_dec_and_test(a) ((--((a)->counter)) == 0)
237 #define cfs_atomic_dec_and_lock(a,b) ((--((a)->counter)) == 0)
238 #define cfs_atomic_inc(a) (((a)->counter)++)
239 #define cfs_atomic_dec(a) do { (a)->counter--; } while (0)
240 #define cfs_atomic_add(b,a) do {(a)->counter += b;} while (0)
241 #define cfs_atomic_add_return(n,a) ((a)->counter += n)
242 #define cfs_atomic_inc_return(a) cfs_atomic_add_return(1,a)
243 #define cfs_atomic_sub(b,a) do {(a)->counter -= b;} while (0)
244 #define cfs_atomic_sub_return(n,a) ((a)->counter -= n)
245 #define cfs_atomic_dec_return(a) cfs_atomic_sub_return(1,a)
246 #define cfs_atomic_add_unless(v, a, u) \
247 ((v)->counter != u ? (v)->counter += a : 0)
248 #define cfs_atomic_inc_not_zero(v) cfs_atomic_add_unless((v), 1, 0)
250 #ifdef HAVE_LIBPTHREAD
254 * Multi-threaded user space completion APIs
259 pthread_cond_t c_cond;
260 pthread_mutex_t c_mut;
261 } cfs_mt_completion_t;
263 void cfs_mt_init_completion(cfs_mt_completion_t *c);
264 void cfs_mt_fini_completion(cfs_mt_completion_t *c);
265 void cfs_mt_complete(cfs_mt_completion_t *c);
266 void cfs_mt_wait_for_completion(cfs_mt_completion_t *c);
269 * Multi-threaded user space atomic APIs
272 typedef struct { volatile int counter; } cfs_mt_atomic_t;
274 int cfs_mt_atomic_read(cfs_mt_atomic_t *a);
275 void cfs_mt_atomic_set(cfs_mt_atomic_t *a, int b);
276 int cfs_mt_atomic_dec_and_test(cfs_mt_atomic_t *a);
277 void cfs_mt_atomic_inc(cfs_mt_atomic_t *a);
278 void cfs_mt_atomic_dec(cfs_mt_atomic_t *a);
279 void cfs_mt_atomic_add(int b, cfs_mt_atomic_t *a);
280 void cfs_mt_atomic_sub(int b, cfs_mt_atomic_t *a);
282 #endif /* HAVE_LIBPTHREAD */
284 /**************************************************************************
288 **************************************************************************/
289 typedef struct cfs_semaphore cfs_mutex_t;
291 #define CFS_DEFINE_MUTEX(m) CFS_DEFINE_SEMAPHORE(m)
293 static inline void cfs_mutex_init(cfs_mutex_t *mutex)
295 cfs_sema_init(mutex, 1);
298 static inline void cfs_mutex_lock(cfs_mutex_t *mutex)
303 static inline void cfs_mutex_unlock(cfs_mutex_t *mutex)
308 static inline int cfs_mutex_lock_interruptible(cfs_mutex_t *mutex)
310 return cfs_down_interruptible(mutex);
314 * Try-lock this mutex.
316 * Note, return values are negation of what is expected from down_trylock() or
317 * pthread_mutex_trylock().
319 * \retval 1 try-lock succeeded (lock acquired).
320 * \retval 0 indicates lock contention.
322 static inline int cfs_mutex_trylock(cfs_mutex_t *mutex)
324 return !cfs_down_trylock(mutex);
327 static inline void cfs_mutex_destroy(cfs_mutex_t *lock)
332 * This is for use in assertions _only_, i.e., this function should always
335 * \retval 1 mutex is locked.
337 * \retval 0 mutex is not locked. This should never happen.
339 static inline int cfs_mutex_is_locked(cfs_mutex_t *lock)
345 /**************************************************************************
347 * Lockdep "implementation". Also see lustre_compat25.h
349 **************************************************************************/
351 typedef struct cfs_lock_class_key {
353 } cfs_lock_class_key_t;
355 static inline void cfs_lockdep_set_class(void *lock,
356 cfs_lock_class_key_t *key)
360 static inline void cfs_lockdep_off(void)
364 static inline void cfs_lockdep_on(void)
368 #define cfs_mutex_lock_nested(mutex, subclass) cfs_mutex_lock(mutex)
369 #define cfs_spin_lock_nested(lock, subclass) cfs_spin_lock(lock)
370 #define cfs_down_read_nested(lock, subclass) cfs_down_read(lock)
371 #define cfs_down_write_nested(lock, subclass) cfs_down_write(lock)
377 /* __LIBCFS_USER_LOCK_H__ */
381 * c-indentation-style: "K&R"