* UCRL-CODE-235197
*
* This file is part of the SPL, Solaris Porting Layer.
- * For details, see <http://github.com/behlendorf/spl/>.
+ * For details, see <http://zfsonlinux.org/>.
*
* The SPL is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
\*****************************************************************************/
#include <sys/condvar.h>
-#include <spl-debug.h>
-
-#ifdef SS_DEBUG_SUBSYS
-#undef SS_DEBUG_SUBSYS
-#endif
-
-#define SS_DEBUG_SUBSYS SS_CONDVAR
void
__cv_init(kcondvar_t *cvp, char *name, kcv_type_t type, void *arg)
{
- int flags = KM_SLEEP;
-
- SENTRY;
ASSERT(cvp);
- ASSERT(name);
+ ASSERT(name == NULL);
ASSERT(type == CV_DEFAULT);
ASSERT(arg == NULL);
cvp->cv_magic = CV_MAGIC;
init_waitqueue_head(&cvp->cv_event);
+ init_waitqueue_head(&cvp->cv_destroy);
atomic_set(&cvp->cv_waiters, 0);
+ atomic_set(&cvp->cv_refs, 1);
cvp->cv_mutex = NULL;
- cvp->cv_name = NULL;
- cvp->cv_name_size = strlen(name) + 1;
-
- /* We may be called when there is a non-zero preempt_count or
- * interrupts are disabled is which case we must not sleep.
- */
- if (current_thread_info()->preempt_count || irqs_disabled())
- flags = KM_NOSLEEP;
+}
+EXPORT_SYMBOL(__cv_init);
- cvp->cv_name = kmem_alloc(cvp->cv_name_size, flags);
- if (cvp->cv_name)
- strcpy(cvp->cv_name, name);
+static int
+cv_destroy_wakeup(kcondvar_t *cvp)
+{
+ if (!atomic_read(&cvp->cv_waiters) && !atomic_read(&cvp->cv_refs)) {
+ ASSERT(cvp->cv_mutex == NULL);
+ ASSERT(!waitqueue_active(&cvp->cv_event));
+ return 1;
+ }
- SEXIT;
+ return 0;
}
-EXPORT_SYMBOL(__cv_init);
void
__cv_destroy(kcondvar_t *cvp)
{
- SENTRY;
ASSERT(cvp);
ASSERT(cvp->cv_magic == CV_MAGIC);
- ASSERT(cvp->cv_mutex == NULL);
- ASSERT(atomic_read(&cvp->cv_waiters) == 0);
- ASSERT(!waitqueue_active(&cvp->cv_event));
- if (cvp->cv_name)
- kmem_free(cvp->cv_name, cvp->cv_name_size);
+ cvp->cv_magic = CV_DESTROY;
+ atomic_dec(&cvp->cv_refs);
+
+ /* Block until all waiters are woken and references dropped. */
+ while (cv_destroy_wakeup(cvp) == 0)
+ wait_event_timeout(cvp->cv_destroy, cv_destroy_wakeup(cvp), 1);
- ASSERT3P(memset(cvp, CV_POISON, sizeof(*cvp)), ==, cvp);
- SEXIT;
+ ASSERT3P(cvp->cv_mutex, ==, NULL);
+ ASSERT3S(atomic_read(&cvp->cv_refs), ==, 0);
+ ASSERT3S(atomic_read(&cvp->cv_waiters), ==, 0);
+ ASSERT3S(waitqueue_active(&cvp->cv_event), ==, 0);
}
EXPORT_SYMBOL(__cv_destroy);
static void
-cv_wait_common(kcondvar_t *cvp, kmutex_t *mp, int state)
+cv_wait_common(kcondvar_t *cvp, kmutex_t *mp, int state, int io)
{
DEFINE_WAIT(wait);
- SENTRY;
ASSERT(cvp);
ASSERT(mp);
ASSERT(cvp->cv_magic == CV_MAGIC);
ASSERT(mutex_owned(mp));
+ atomic_inc(&cvp->cv_refs);
if (cvp->cv_mutex == NULL)
cvp->cv_mutex = mp;
* ensures we're linked in to the waiters list and avoids the
* race where 'cvp->cv_waiters > 0' but the list is empty. */
mutex_exit(mp);
- schedule();
+ if (io)
+ io_schedule();
+ else
+ schedule();
mutex_enter(mp);
/* No more waiters a different mutex could be used */
- if (atomic_dec_and_test(&cvp->cv_waiters))
+ if (atomic_dec_and_test(&cvp->cv_waiters)) {
cvp->cv_mutex = NULL;
+ wake_up(&cvp->cv_destroy);
+ }
finish_wait(&cvp->cv_event, &wait);
- SEXIT;
+ atomic_dec(&cvp->cv_refs);
}
void
__cv_wait(kcondvar_t *cvp, kmutex_t *mp)
{
- cv_wait_common(cvp, mp, TASK_UNINTERRUPTIBLE);
+ cv_wait_common(cvp, mp, TASK_UNINTERRUPTIBLE, 0);
}
EXPORT_SYMBOL(__cv_wait);
void
__cv_wait_interruptible(kcondvar_t *cvp, kmutex_t *mp)
{
- cv_wait_common(cvp, mp, TASK_INTERRUPTIBLE);
+ cv_wait_common(cvp, mp, TASK_INTERRUPTIBLE, 0);
}
EXPORT_SYMBOL(__cv_wait_interruptible);
+void
+__cv_wait_io(kcondvar_t *cvp, kmutex_t *mp)
+{
+ cv_wait_common(cvp, mp, TASK_UNINTERRUPTIBLE, 1);
+}
+EXPORT_SYMBOL(__cv_wait_io);
+
/* 'expire_time' argument is an absolute wall clock time in jiffies.
* Return value is time left (expire_time - now) or -1 if timeout occurred.
*/
{
DEFINE_WAIT(wait);
clock_t time_left;
- SENTRY;
ASSERT(cvp);
ASSERT(mp);
ASSERT(cvp->cv_magic == CV_MAGIC);
ASSERT(mutex_owned(mp));
+ atomic_inc(&cvp->cv_refs);
if (cvp->cv_mutex == NULL)
cvp->cv_mutex = mp;
/* XXX - Does not handle jiffie wrap properly */
time_left = expire_time - jiffies;
- if (time_left <= 0)
- SRETURN(-1);
+ if (time_left <= 0) {
+ atomic_dec(&cvp->cv_refs);
+ return (-1);
+ }
prepare_to_wait_exclusive(&cvp->cv_event, &wait, state);
atomic_inc(&cvp->cv_waiters);
mutex_enter(mp);
/* No more waiters a different mutex could be used */
- if (atomic_dec_and_test(&cvp->cv_waiters))
+ if (atomic_dec_and_test(&cvp->cv_waiters)) {
cvp->cv_mutex = NULL;
+ wake_up(&cvp->cv_destroy);
+ }
finish_wait(&cvp->cv_event, &wait);
+ atomic_dec(&cvp->cv_refs);
- SRETURN(time_left > 0 ? time_left : -1);
+ return (time_left > 0 ? time_left : -1);
}
clock_t
}
EXPORT_SYMBOL(__cv_timedwait_interruptible);
+/*
+ *'expire_time' argument is an absolute clock time in nanoseconds.
+ * Return value is time left (expire_time - now) or -1 if timeout occurred.
+ */
+static clock_t
+__cv_timedwait_hires(kcondvar_t *cvp, kmutex_t *mp,
+ hrtime_t expire_time, int state)
+{
+ DEFINE_WAIT(wait);
+ hrtime_t time_left, now;
+ unsigned long time_left_us;
+
+ ASSERT(cvp);
+ ASSERT(mp);
+ ASSERT(cvp->cv_magic == CV_MAGIC);
+ ASSERT(mutex_owned(mp));
+ atomic_inc(&cvp->cv_refs);
+
+ if (cvp->cv_mutex == NULL)
+ cvp->cv_mutex = mp;
+
+ /* Ensure the same mutex is used by all callers */
+ ASSERT(cvp->cv_mutex == mp);
+
+ now = gethrtime();
+ time_left = expire_time - now;
+ if (time_left <= 0) {
+ atomic_dec(&cvp->cv_refs);
+ return (-1);
+ }
+ time_left_us = time_left / NSEC_PER_USEC;
+
+ prepare_to_wait_exclusive(&cvp->cv_event, &wait, state);
+ atomic_inc(&cvp->cv_waiters);
+
+ /* Mutex should be dropped after prepare_to_wait() this
+ * ensures we're linked in to the waiters list and avoids the
+ * race where 'cvp->cv_waiters > 0' but the list is empty. */
+ mutex_exit(mp);
+ /* Allow a 100 us range to give kernel an opportunity to coalesce
+ * interrupts */
+ usleep_range(time_left_us, time_left_us + 100);
+ mutex_enter(mp);
+
+ /* No more waiters a different mutex could be used */
+ if (atomic_dec_and_test(&cvp->cv_waiters)) {
+ cvp->cv_mutex = NULL;
+ wake_up(&cvp->cv_destroy);
+ }
+
+ finish_wait(&cvp->cv_event, &wait);
+ atomic_dec(&cvp->cv_refs);
+
+ time_left = expire_time - gethrtime();
+ return (time_left > 0 ? time_left : -1);
+}
+
+/*
+ * Compatibility wrapper for the cv_timedwait_hires() Illumos interface.
+ */
+clock_t
+cv_timedwait_hires(kcondvar_t *cvp, kmutex_t *mp, hrtime_t tim,
+ hrtime_t res, int flag)
+{
+ if (res > 1) {
+ /*
+ * Align expiration to the specified resolution.
+ */
+ if (flag & CALLOUT_FLAG_ROUNDUP)
+ tim += res - 1;
+ tim = (tim / res) * res;
+ }
+
+ if (!(flag & CALLOUT_FLAG_ABSOLUTE))
+ tim += gethrtime();
+
+ return __cv_timedwait_hires(cvp, mp, tim, TASK_UNINTERRUPTIBLE);
+}
+EXPORT_SYMBOL(cv_timedwait_hires);
+
void
__cv_signal(kcondvar_t *cvp)
{
- SENTRY;
ASSERT(cvp);
ASSERT(cvp->cv_magic == CV_MAGIC);
+ atomic_inc(&cvp->cv_refs);
/* All waiters are added with WQ_FLAG_EXCLUSIVE so only one
* waiter will be set runable with each call to wake_up().
if (atomic_read(&cvp->cv_waiters) > 0)
wake_up(&cvp->cv_event);
- SEXIT;
+ atomic_dec(&cvp->cv_refs);
}
EXPORT_SYMBOL(__cv_signal);
{
ASSERT(cvp);
ASSERT(cvp->cv_magic == CV_MAGIC);
- SENTRY;
+ atomic_inc(&cvp->cv_refs);
/* Wake_up_all() will wake up all waiters even those which
* have the WQ_FLAG_EXCLUSIVE flag set. */
if (atomic_read(&cvp->cv_waiters) > 0)
wake_up_all(&cvp->cv_event);
- SEXIT;
+ atomic_dec(&cvp->cv_refs);
}
EXPORT_SYMBOL(__cv_broadcast);
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