aboutsummaryrefslogtreecommitdiffstats
path: root/include/os/freebsd/spl/sys/condvar.h
blob: 9b1893bcb84ca46c92a90552fceca8a1a825205c (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
/*
 * Copyright (c) 2007 Pawel Jakub Dawidek <pjd@FreeBSD.org>
 * Copyright (c) 2013 iXsystems, Inc.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * $FreeBSD$
 */

#ifndef _OPENSOLARIS_SYS_CONDVAR_H_
#define	_OPENSOLARIS_SYS_CONDVAR_H_

#include <sys/param.h>
#include <sys/systm.h>

#include <sys/spl_condvar.h>
#include <sys/mutex.h>
#include <sys/time.h>
#include <sys/errno.h>

/*
 * cv_timedwait() is similar to cv_wait() except that it additionally expects
 * a timeout value specified in ticks.  When woken by cv_signal() or
 * cv_broadcast() it returns 1, otherwise when the timeout is reached -1 is
 * returned.
 *
 * cv_timedwait_sig() behaves the same as cv_timedwait() but blocks
 * interruptibly and can be woken by a signal (EINTR, ERESTART).  When
 * this occurs 0 is returned.
 *
 * cv_timedwait_io() and cv_timedwait_sig_io() are variants of cv_timedwait()
 * and cv_timedwait_sig() which should be used when waiting for outstanding
 * IO to complete.  They are responsible for updating the iowait accounting
 * when this is supported by the platform.
 *
 * cv_timedwait_hires() and cv_timedwait_sig_hires() are high resolution
 * versions of cv_timedwait() and cv_timedwait_sig().  They expect the timeout
 * to be specified as a hrtime_t allowing for timeouts of less than a tick.
 *
 * N.B. The return values differ slightly from the illumos implementation
 * which returns the time remaining, instead of 1, when woken.  They both
 * return -1 on timeout. Consumers which need to know the time remaining
 * are responsible for tracking it themselves.
 */

static __inline sbintime_t
zfs_nstosbt(int64_t _ns)
{
	sbintime_t sb = 0;

#ifdef KASSERT
	KASSERT(_ns >= 0, ("Negative values illegal for nstosbt: %jd", _ns));
#endif
	if (_ns >= SBT_1S) {
		sb = (_ns / 1000000000) * SBT_1S;
		_ns = _ns % 1000000000;
	}
	/* 9223372037 = ceil(2^63 / 1000000000) */
	sb += ((_ns * 9223372037ull) + 0x7fffffff) >> 31;
	return (sb);
}


typedef struct cv	kcondvar_t;
#define	CALLOUT_FLAG_ABSOLUTE C_ABSOLUTE

typedef enum {
	CV_DEFAULT,
	CV_DRIVER
} kcv_type_t;

#define	zfs_cv_init(cv, name, type, arg)	do {			\
	const char *_name;						\
	ASSERT((type) == CV_DEFAULT);					\
	for (_name = #cv; *_name != '\0'; _name++) {			\
		if (*_name >= 'a' && *_name <= 'z')			\
			break;						\
	}								\
	if (*_name == '\0')						\
		_name = #cv;						\
	cv_init((cv), _name);						\
} while (0)
#define	cv_init(cv, name, type, arg)	zfs_cv_init(cv, name, type, arg)


static inline int
cv_wait_sig(kcondvar_t *cvp, kmutex_t *mp)
{

	return (_cv_wait_sig(cvp, &(mp)->lock_object) == 0);
}

static inline int
cv_timedwait(kcondvar_t *cvp, kmutex_t *mp, clock_t timo)
{
	int rc;

	timo -= ddi_get_lbolt();
	if (timo <= 0)
		return (-1);
	rc = _cv_timedwait_sbt((cvp), &(mp)->lock_object, \
	    tick_sbt * (timo), 0, C_HARDCLOCK);
	if (rc == EWOULDBLOCK)
		return (-1);
	return (1);
}

static inline int
cv_timedwait_sig(kcondvar_t *cvp, kmutex_t *mp, clock_t timo)
{
	int rc;

	timo -= ddi_get_lbolt();
	if (timo <= 0)
		return (-1);
	rc = _cv_timedwait_sig_sbt(cvp, &(mp)->lock_object, \
	    tick_sbt * (timo), 0, C_HARDCLOCK);
	if (rc == EWOULDBLOCK)
		return (-1);
	if (rc == EINTR || rc == ERESTART)
		return (0);

	return (1);
}

#define	cv_timedwait_io		cv_timedwait
#define	cv_timedwait_idle	cv_timedwait
#define	cv_timedwait_sig_io	cv_timedwait_sig
#define	cv_wait_io		cv_wait
#define	cv_wait_io_sig		cv_wait_sig
#define	cv_wait_idle		cv_wait
#define	cv_timedwait_io_hires	cv_timedwait_hires
#define	cv_timedwait_idle_hires cv_timedwait_hires

static inline int
cv_timedwait_hires(kcondvar_t *cvp, kmutex_t *mp, hrtime_t tim, hrtime_t res,
    int flag)
{
	hrtime_t hrtime;
	int rc;

	ASSERT(tim >= res);

	hrtime = gethrtime();
	if (flag == 0)
		tim += hrtime;

	if (hrtime >= tim)
		return (-1);
	rc = cv_timedwait_sbt(cvp, mp, zfs_nstosbt(tim),
	    zfs_nstosbt(res), C_ABSOLUTE);

	if (rc == EWOULDBLOCK)
		return (-1);

	KASSERT(rc == 0, ("unexpected rc value %d", rc));
	return (1);
}

static inline int
cv_timedwait_sig_hires(kcondvar_t *cvp, kmutex_t *mp, hrtime_t tim,
    hrtime_t res, int flag)
{
	sbintime_t sbt;
	hrtime_t hrtime;
	int rc;

	ASSERT(tim >= res);

	hrtime = gethrtime();
	if (flag == 0)
		tim += hrtime;

	if (hrtime >= tim)
		return (-1);

	sbt = zfs_nstosbt(tim);
	rc = cv_timedwait_sig_sbt(cvp, mp, sbt, zfs_nstosbt(res), C_ABSOLUTE);

	switch (rc) {
	case EWOULDBLOCK:
		return (-1);
	case EINTR:
	case ERESTART:
		return (0);
	default:
		KASSERT(rc == 0, ("unexpected rc value %d", rc));
		return (1);
	}
}

#endif	/* _OPENSOLARIS_SYS_CONDVAR_H_ */