1 /* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
2 * vim:expandtab:shiftwidth=8:tabstop=8:
6 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 only,
10 * as published by the Free Software Foundation.
12 * This program is distributed in the hope that it will be useful, but
13 * WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * General Public License version 2 for more details (a copy is included
16 * in the LICENSE file that accompanied this code).
18 * You should have received a copy of the GNU General Public License
19 * version 2 along with this program; If not, see
20 * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
22 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
23 * CA 95054 USA or visit www.sun.com if you need additional information or
29 * Copyright 2008 Sun Microsystems, Inc. All rights reserved
30 * Use is subject to license terms.
33 * This file is part of Lustre, http://www.lustre.org/
34 * Lustre is a trademark of Sun Microsystems, Inc.
36 * libcfs/include/libcfs/user-lock.h
38 * Author: Nikita Danilov <nikita@clusterfs.com>
41 #ifndef __LIBCFS_USER_LOCK_H__
42 #define __LIBCFS_USER_LOCK_H__
44 #ifndef __LIBCFS_LIBCFS_H__
45 #error Do not #include this file directly. #include <libcfs/libcfs.h> instead
48 /* Implementations of portable synchronization APIs for liblustre */
51 * liblustre is single-threaded, so most "synchronization" APIs are trivial.
53 * XXX Liang: There are several branches share lnet with b_hd_newconfig,
54 * if we define lock APIs at here, there will be conflict with liblustre
61 * The userspace implementations of linux/spinlock.h vary; we just
62 * include our own for all of them
64 #define __LINUX_SPINLOCK_H
67 * Optional debugging (magic stamping and checking ownership) can be added.
78 * - spin_lock_irqsave(x, f)
79 * - spin_unlock_irqrestore(x, f)
81 * No-op implementation.
83 struct spin_lock {int foo;};
85 typedef struct spin_lock spinlock_t;
87 #define SPIN_LOCK_UNLOCKED (spinlock_t) { }
88 #define LASSERT_SPIN_LOCKED(lock) do {} while(0)
89 #define LASSERT_SEM_LOCKED(sem) do {} while(0)
91 void spin_lock_init(spinlock_t *lock);
92 void spin_lock(spinlock_t *lock);
93 void spin_unlock(spinlock_t *lock);
94 int spin_trylock(spinlock_t *lock);
95 void spin_lock_bh_init(spinlock_t *lock);
96 void spin_lock_bh(spinlock_t *lock);
97 void spin_unlock_bh(spinlock_t *lock);
99 static inline int spin_is_locked(spinlock_t *l) {return 1;}
100 static inline void spin_lock_irqsave(spinlock_t *l, unsigned long f){}
101 static inline void spin_unlock_irqrestore(spinlock_t *l, unsigned long f){}
110 typedef struct semaphore {
114 void sema_init(struct semaphore *s, int val);
115 void __down(struct semaphore *s);
116 void __up(struct semaphore *s);
122 * - init_mutex_locked(x)
126 #define DECLARE_MUTEX(name) \
127 struct semaphore name = { 1 }
129 #define mutex_up(s) __up(s)
130 #define up(s) mutex_up(s)
131 #define mutex_down(s) __down(s)
132 #define down(s) mutex_down(s)
134 #define init_MUTEX(x) sema_init(x, 1)
135 #define init_MUTEX_LOCKED(x) sema_init(x, 0)
136 #define init_mutex(s) init_MUTEX(s)
141 * - init_completion(c)
143 * - wait_for_completion(c)
150 void init_completion(struct completion *c);
151 void complete(struct completion *c);
152 void wait_for_completion(struct completion *c);
153 int wait_for_completion_interruptible(struct completion *c);
155 #define COMPLETION_INITIALIZER(work) \
156 { 0, __WAIT_QUEUE_HEAD_INITIALIZER((work).wait) }
158 #define DECLARE_COMPLETION(work) \
159 struct completion work = COMPLETION_INITIALIZER(work)
161 #define INIT_COMPLETION(x) ((x).done = 0)
173 struct rw_semaphore {
177 void init_rwsem(struct rw_semaphore *s);
178 void down_read(struct rw_semaphore *s);
179 int down_read_trylock(struct rw_semaphore *s);
180 void down_write(struct rw_semaphore *s);
181 int down_write_trylock(struct rw_semaphore *s);
182 void up_read(struct rw_semaphore *s);
183 void up_write(struct rw_semaphore *s);
186 * read-write lock : Need to be investigated more!!
187 * XXX nikita: for now, let rwlock_t to be identical to rw_semaphore
189 * - DECLARE_RWLOCK(l)
196 typedef struct rw_semaphore rwlock_t;
197 #define RW_LOCK_UNLOCKED (rwlock_t) { }
199 #define rwlock_init(pl) init_rwsem(pl)
201 #define read_lock(l) down_read(l)
202 #define read_unlock(l) up_read(l)
203 #define write_lock(l) down_write(l)
204 #define write_unlock(l) up_write(l)
207 write_lock_irqsave(rwlock_t *l, unsigned long f) { write_lock(l); }
209 write_unlock_irqrestore(rwlock_t *l, unsigned long f) { write_unlock(l); }
212 read_lock_irqsave(rwlock_t *l, unsigned long f) { read_lock(l); }
214 read_unlock_irqrestore(rwlock_t *l, unsigned long f) { read_unlock(l); }
217 * Atomic for user-space
218 * Copied from liblustre
220 typedef struct { volatile int counter; } atomic_t;
222 #define ATOMIC_INIT(i) { (i) }
224 #define atomic_read(a) ((a)->counter)
225 #define atomic_set(a,b) do {(a)->counter = b; } while (0)
226 #define atomic_dec_and_test(a) ((--((a)->counter)) == 0)
227 #define atomic_dec_and_lock(a,b) ((--((a)->counter)) == 0)
228 #define atomic_inc(a) (((a)->counter)++)
229 #define atomic_dec(a) do { (a)->counter--; } while (0)
230 #define atomic_add(b,a) do {(a)->counter += b;} while (0)
231 #define atomic_add_return(n,a) ((a)->counter += n)
232 #define atomic_inc_return(a) atomic_add_return(1,a)
233 #define atomic_sub(b,a) do {(a)->counter -= b;} while (0)
234 #define atomic_sub_return(n,a) ((a)->counter -= n)
235 #define atomic_dec_return(a) atomic_sub_return(1,a)
238 #ifdef HAVE_LIBPTHREAD
245 struct cfs_completion {
247 pthread_cond_t c_cond;
248 pthread_mutex_t c_mut;
251 void cfs_init_completion(struct cfs_completion *c);
252 void cfs_fini_completion(struct cfs_completion *c);
253 void cfs_complete(struct cfs_completion *c);
254 void cfs_wait_for_completion(struct cfs_completion *c);
260 typedef struct { volatile int counter; } cfs_atomic_t;
262 int cfs_atomic_read(cfs_atomic_t *a);
263 void cfs_atomic_set(cfs_atomic_t *a, int b);
264 int cfs_atomic_dec_and_test(cfs_atomic_t *a);
265 void cfs_atomic_inc(cfs_atomic_t *a);
266 void cfs_atomic_dec(cfs_atomic_t *a);
267 void cfs_atomic_add(int b, cfs_atomic_t *a);
268 void cfs_atomic_sub(int b, cfs_atomic_t *a);
270 #endif /* HAVE_LIBPTHREAD */
272 /**************************************************************************
276 **************************************************************************/
279 struct semaphore m_sem;
282 static inline void mutex_init(struct mutex *mutex)
284 init_mutex(&mutex->m_sem);
287 static inline void mutex_lock(struct mutex *mutex)
289 mutex_down(&mutex->m_sem);
292 static inline void mutex_unlock(struct mutex *mutex)
294 mutex_up(&mutex->m_sem);
298 * Try-lock this mutex.
300 * \retval 1 try-lock succeeded.
302 * \retval 0 try-lock failed.
304 static inline int mutex_trylock(struct mutex *mutex)
309 static inline void mutex_destroy(struct mutex *lock)
314 * This is for use in assertions _only_, i.e., this function should always
317 * \retval 1 mutex is locked.
319 * \retval 0 mutex is not locked. This should never happen.
321 static inline int mutex_is_locked(struct mutex *lock)
327 /**************************************************************************
329 * Lockdep "implementation". Also see lustre_compat25.h
331 **************************************************************************/
333 struct lock_class_key {
337 static inline void lockdep_set_class(void *lock, struct lock_class_key *key)
341 /* This has to be a macro, so that can be undefined in kernels that do not
342 * support lockdep. */
343 #define mutex_lock_nested(mutex, subclass) mutex_lock(mutex)
344 #define spin_lock_nested(lock, subclass) spin_lock(lock)
345 #define down_read_nested(lock, subclass) down_read(lock)
346 #define down_write_nested(lock, subclass) down_write(lock)
351 /* __LIBCFS_USER_LOCK_H__ */
355 * c-indentation-style: "K&R"