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/*
* 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>
/*
* 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_sig_io cv_timedwait_sig
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_ */
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