2 * Copyright (C) 2007-2010 Lawrence Livermore National Security, LLC.
3 * Copyright (C) 2007 The Regents of the University of California.
4 * Produced at Lawrence Livermore National Laboratory (cf, DISCLAIMER).
5 * Written by Brian Behlendorf <behlendorf1@llnl.gov>.
8 * This file is part of the SPL, Solaris Porting Layer.
9 * For details, see <http://zfsonlinux.org/>.
11 * The SPL is free software; you can redistribute it and/or modify it
12 * under the terms of the GNU General Public License as published by the
13 * Free Software Foundation; either version 2 of the License, or (at your
14 * option) any later version.
16 * The SPL is distributed in the hope that it will be useful, but WITHOUT
17 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
18 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
21 * You should have received a copy of the GNU General Public License along
22 * with the SPL. If not, see <http://www.gnu.org/licenses/>.
25 #ifndef _SPL_CONDVAR_H
26 #define _SPL_CONDVAR_H
28 #include <linux/module.h>
30 #include <sys/mutex.h>
31 #include <sys/callo.h>
36 * cv_timedwait() is similar to cv_wait() except that it additionally expects
37 * a timeout value specified in ticks. When woken by cv_signal() or
38 * cv_broadcast() it returns 1, otherwise when the timeout is reached -1 is
41 * cv_timedwait_sig() behaves the same as cv_timedwait() but blocks
42 * interruptibly and can be woken by a signal (EINTR, ERESTART). When
43 * this occurs 0 is returned.
45 * cv_timedwait_io() and cv_timedwait_sig_io() are variants of cv_timedwait()
46 * and cv_timedwait_sig() which should be used when waiting for outstanding
47 * IO to complete. They are responsible for updating the iowait accounting
48 * when this is supported by the platform.
50 * cv_timedwait_hires() and cv_timedwait_sig_hires() are high resolution
51 * versions of cv_timedwait() and cv_timedwait_sig(). They expect the timeout
52 * to be specified as a hrtime_t allowing for timeouts of less than a tick.
54 * N.B. The return values differ slightly from the illumos implementation
55 * which returns the time remaining, instead of 1, when woken. They both
56 * return -1 on timeout. Consumers which need to know the time remaining
57 * are responsible for tracking it themselves.
62 * The kcondvar_t struct is protected by mutex taken externally before
63 * calling any of the wait/signal funs, and passed into the wait funs.
65 #define CV_MAGIC 0x346545f4
66 #define CV_DESTROY 0x346545f5
70 spl_wait_queue_head_t cv_event;
71 spl_wait_queue_head_t cv_destroy;
77 typedef enum { CV_DEFAULT = 0, CV_DRIVER } kcv_type_t;
79 extern void __cv_init(kcondvar_t *, char *, kcv_type_t, void *);
80 extern void __cv_destroy(kcondvar_t *);
81 extern void __cv_wait(kcondvar_t *, kmutex_t *);
82 extern void __cv_wait_io(kcondvar_t *, kmutex_t *);
83 extern void __cv_wait_idle(kcondvar_t *, kmutex_t *);
84 extern int __cv_wait_io_sig(kcondvar_t *, kmutex_t *);
85 extern int __cv_wait_sig(kcondvar_t *, kmutex_t *);
86 extern int __cv_timedwait(kcondvar_t *, kmutex_t *, clock_t);
87 extern int __cv_timedwait_io(kcondvar_t *, kmutex_t *, clock_t);
88 extern int __cv_timedwait_sig(kcondvar_t *, kmutex_t *, clock_t);
89 extern int __cv_timedwait_idle(kcondvar_t *, kmutex_t *, clock_t);
90 extern int cv_timedwait_hires(kcondvar_t *, kmutex_t *, hrtime_t,
91 hrtime_t res, int flag);
92 extern int cv_timedwait_sig_hires(kcondvar_t *, kmutex_t *, hrtime_t,
93 hrtime_t res, int flag);
94 extern int cv_timedwait_idle_hires(kcondvar_t *, kmutex_t *, hrtime_t,
95 hrtime_t res, int flag);
96 extern void __cv_signal(kcondvar_t *);
97 extern void __cv_broadcast(kcondvar_t *c);
99 #define cv_init(cvp, name, type, arg) __cv_init(cvp, name, type, arg)
100 #define cv_destroy(cvp) __cv_destroy(cvp)
101 #define cv_wait(cvp, mp) __cv_wait(cvp, mp)
102 #define cv_wait_io(cvp, mp) __cv_wait_io(cvp, mp)
103 #define cv_wait_idle(cvp, mp) __cv_wait_idle(cvp, mp)
104 #define cv_wait_io_sig(cvp, mp) __cv_wait_io_sig(cvp, mp)
105 #define cv_wait_sig(cvp, mp) __cv_wait_sig(cvp, mp)
106 #define cv_signal(cvp) __cv_signal(cvp)
107 #define cv_broadcast(cvp) __cv_broadcast(cvp)
110 * NB: There is no way to reliably distinguish between having been signalled
111 * and having timed out on Linux. If the client code needs to reliably
112 * distinguish between the two it should use the hires variant.
114 #define cv_timedwait(cvp, mp, t) __cv_timedwait(cvp, mp, t)
115 #define cv_timedwait_io(cvp, mp, t) __cv_timedwait_io(cvp, mp, t)
116 #define cv_timedwait_sig(cvp, mp, t) __cv_timedwait_sig(cvp, mp, t)
117 #define cv_timedwait_idle(cvp, mp, t) __cv_timedwait_idle(cvp, mp, t)
120 #endif /* _SPL_CONDVAR_H */