void
_sx_xunlock(struct sx *sx, const char *file, int line)
{
_sx_assert(sx, SX_XLOCKED, file, line);
mtx_lock(sx->sx_lock);
MPASS(sx->sx_cnt == -1);
WITNESS_UNLOCK(&sx->sx_object, LOP_EXCLUSIVE, file, line);
/* Release. */
sx->sx_cnt++;
sx->sx_xholder = NULL;
/*
* Wake up waiters if there are any. Give precedence to slock waiters.
*/
if (sx->sx_shrd_wcnt > 0)
cv_broadcast(&sx->sx_shrd_cv);
else if (sx->sx_excl_wcnt > 0)
cv_signal(&sx->sx_excl_cv);
LOCK_LOG_LOCK("XUNLOCK", &sx->sx_object, 0, 0, file, line);
mtx_unlock(sx->sx_lock);
}
void
_sx_sunlock(struct sx *sx, const char *file, int line)
{
_sx_assert(sx, SX_SLOCKED, file, line);
mtx_lock(sx->sx_lock);
WITNESS_UNLOCK(&sx->sx_object, 0, file, line);
/* Release. */
sx->sx_cnt--;
/*
* If we just released the last shared lock, wake any waiters up, giving
* exclusive lockers precedence. In order to make sure that exclusive
* lockers won't be blocked forever, don't wake shared lock waiters if
* there are exclusive lock waiters.
*/
if (sx->sx_excl_wcnt > 0) {
if (sx->sx_cnt == 0)
cv_signal(&sx->sx_excl_cv);
} else if (sx->sx_shrd_wcnt > 0)
cv_broadcast(&sx->sx_shrd_cv);
LOCK_LOG_LOCK("SUNLOCK", &sx->sx_object, 0, 0, file, line);
mtx_unlock(sx->sx_lock);
}
void
_sx_sunlock(struct sx *sx, const char *file, int line)
{
if (SCHEDULER_STOPPED())
return;
KASSERT(sx->sx_lock != SX_LOCK_DESTROYED,
("sx_sunlock() of destroyed sx @ %s:%d", file, line));
_sx_assert(sx, SA_SLOCKED, file, line);
WITNESS_UNLOCK(&sx->lock_object, 0, file, line);
LOCK_LOG_LOCK("SUNLOCK", &sx->lock_object, 0, 0, file, line);
__sx_sunlock(sx, file, line);
curthread->td_locks--;
}
void
_sx_sunlock(struct sx *sx, const char *file, int line)
{
MPASS(curthread != NULL);
KASSERT(sx->sx_lock != SX_LOCK_DESTROYED,
("sx_sunlock() of destroyed sx @ %s:%d", file, line));
_sx_assert(sx, SA_SLOCKED, file, line);
curthread->td_locks--;
WITNESS_UNLOCK(&sx->lock_object, 0, file, line);
LOCK_LOG_LOCK("SUNLOCK", &sx->lock_object, 0, 0, file, line);
__sx_sunlock(sx, file, line);
LOCKSTAT_PROFILE_RELEASE_LOCK(LS_SX_SUNLOCK_RELEASE, sx);
}
void
_rm_wunlock_debug(struct rmlock *rm, const char *file, int line)
{
if (SCHEDULER_STOPPED())
return;
KASSERT(!rm_destroyed(rm),
("rm_wunlock() of destroyed rmlock @ %s:%d", file, line));
_rm_assert(rm, RA_WLOCKED, file, line);
WITNESS_UNLOCK(&rm->lock_object, LOP_EXCLUSIVE, file, line);
LOCK_LOG_LOCK("RMWUNLOCK", &rm->lock_object, 0, 0, file, line);
_rm_wunlock(rm);
TD_LOCKS_DEC(curthread);
}
void
_rm_runlock_debug(struct rmlock *rm, struct rm_priotracker *tracker,
const char *file, int line)
{
if (SCHEDULER_STOPPED())
return;
KASSERT(!rm_destroyed(rm),
("rm_runlock() of destroyed rmlock @ %s:%d", file, line));
_rm_assert(rm, RA_RLOCKED, file, line);
WITNESS_UNLOCK(&rm->lock_object, 0, file, line);
LOCK_LOG_LOCK("RMRUNLOCK", &rm->lock_object, 0, 0, file, line);
_rm_runlock(rm, tracker);
TD_LOCKS_DEC(curthread);
}
void
_sx_xunlock(struct sx *sx, const char *file, int line)
{
MPASS(curthread != NULL);
KASSERT(sx->sx_lock != SX_LOCK_DESTROYED,
("sx_xunlock() of destroyed sx @ %s:%d", file, line));
_sx_assert(sx, SA_XLOCKED, file, line);
curthread->td_locks--;
WITNESS_UNLOCK(&sx->lock_object, LOP_EXCLUSIVE, file, line);
LOCK_LOG_LOCK("XUNLOCK", &sx->lock_object, 0, sx->sx_recurse, file,
line);
if (!sx_recursed(sx))
LOCKSTAT_PROFILE_RELEASE_LOCK(LS_SX_XUNLOCK_RELEASE, sx);
__sx_xunlock(sx, curthread, file, line);
}
void
_mtx_unlock_spin_flags(struct mtx *m, int opts, const char *file, int line)
{
MPASS(curthread != NULL);
KASSERT(m->mtx_lock != MTX_DESTROYED,
("mtx_unlock_spin() of destroyed mutex @ %s:%d", file, line));
KASSERT(LOCK_CLASS(&m->lock_object) == &lock_class_mtx_spin,
("mtx_unlock_spin() of sleep mutex %s @ %s:%d",
m->lock_object.lo_name, file, line));
WITNESS_UNLOCK(&m->lock_object, opts | LOP_EXCLUSIVE, file, line);
LOCK_LOG_LOCK("UNLOCK", &m->lock_object, opts, m->mtx_recurse, file,
line);
mtx_assert(m, MA_OWNED);
_rel_spin_lock(m);
}
void
_rw_wunlock(struct rwlock *rw, const char *file, int line)
{
if (SCHEDULER_STOPPED())
return;
KASSERT(rw->rw_lock != RW_DESTROYED,
("rw_wunlock() of destroyed rwlock @ %s:%d", file, line));
_rw_assert(rw, RA_WLOCKED, file, line);
curthread->td_locks--;
WITNESS_UNLOCK(&rw->lock_object, LOP_EXCLUSIVE, file, line);
LOCK_LOG_LOCK("WUNLOCK", &rw->lock_object, 0, rw->rw_recurse, file,
line);
if (!rw_recursed(rw))
LOCKSTAT_PROFILE_RELEASE_LOCK(LS_RW_WUNLOCK_RELEASE, rw);
__rw_wunlock(rw, curthread, file, line);
}
void
_mtx_unlock_flags(struct mtx *m, int opts, const char *file, int line)
{
MPASS(curthread != NULL);
KASSERT(m->mtx_lock != MTX_DESTROYED,
("mtx_unlock() of destroyed mutex @ %s:%d", file, line));
KASSERT(LOCK_CLASS(&m->lock_object) == &lock_class_mtx_sleep,
("mtx_unlock() of spin mutex %s @ %s:%d", m->lock_object.lo_name,
file, line));
curthread->td_locks--;
WITNESS_UNLOCK(&m->lock_object, opts | LOP_EXCLUSIVE, file, line);
LOCK_LOG_LOCK("UNLOCK", &m->lock_object, opts, m->mtx_recurse, file,
line);
mtx_assert(m, MA_OWNED);
if (m->mtx_recurse == 0)
LOCKSTAT_PROFILE_RELEASE_LOCK(LS_MTX_UNLOCK_RELEASE, m);
_rel_sleep_lock(m, curthread, opts, file, line);
}
void
_rw_wunlock_cookie(volatile uintptr_t *c, const char *file, int line)
{
struct rwlock *rw;
if (SCHEDULER_STOPPED())
return;
rw = rwlock2rw(c);
KASSERT(rw->rw_lock != RW_DESTROYED,
("rw_wunlock() of destroyed rwlock @ %s:%d", file, line));
__rw_assert(c, RA_WLOCKED, file, line);
WITNESS_UNLOCK(&rw->lock_object, LOP_EXCLUSIVE, file, line);
LOCK_LOG_LOCK("WUNLOCK", &rw->lock_object, 0, rw->rw_recurse, file,
line);
__rw_wunlock(rw, curthread, file, line);
curthread->td_locks--;
}
void
__mtx_unlock_spin_flags(volatile uintptr_t *c, int opts, const char *file,
int line)
{
struct mtx *m;
m = mtxlock2mtx(c);
KASSERT(m->mtx_lock != MTX_DESTROYED,
("mtx_unlock_spin() of destroyed mutex @ %s:%d", file, line));
KASSERT(LOCK_CLASS(&m->lock_object) == &lock_class_mtx_spin,
("mtx_unlock_spin() of sleep mutex %s @ %s:%d",
m->lock_object.lo_name, file, line));
WITNESS_UNLOCK(&m->lock_object, opts | LOP_EXCLUSIVE, file, line);
LOCK_LOG_LOCK("UNLOCK", &m->lock_object, opts, m->mtx_recurse, file,
line);
mtx_assert(m, MA_OWNED);
__mtx_unlock_spin(m);
}
void
__mtx_unlock_flags(volatile uintptr_t *c, int opts, const char *file, int line)
{
struct mtx *m;
if (SCHEDULER_STOPPED())
return;
m = mtxlock2mtx(c);
KASSERT(m->mtx_lock != MTX_DESTROYED,
("mtx_unlock() of destroyed mutex @ %s:%d", file, line));
KASSERT(LOCK_CLASS(&m->lock_object) == &lock_class_mtx_sleep,
("mtx_unlock() of spin mutex %s @ %s:%d", m->lock_object.lo_name,
file, line));
WITNESS_UNLOCK(&m->lock_object, opts | LOP_EXCLUSIVE, file, line);
LOCK_LOG_LOCK("UNLOCK", &m->lock_object, opts, m->mtx_recurse, file,
line);
mtx_assert(m, MA_OWNED);
__mtx_unlock(m, curthread, opts, file, line);
TD_LOCKS_DEC(curthread);
}
void
_rw_runlock_cookie(volatile uintptr_t *c, const char *file, int line)
{
struct rwlock *rw;
struct turnstile *ts;
uintptr_t x, v, queue;
if (SCHEDULER_STOPPED())
return;
rw = rwlock2rw(c);
KASSERT(rw->rw_lock != RW_DESTROYED,
("rw_runlock() of destroyed rwlock @ %s:%d", file, line));
__rw_assert(c, RA_RLOCKED, file, line);
WITNESS_UNLOCK(&rw->lock_object, 0, file, line);
LOCK_LOG_LOCK("RUNLOCK", &rw->lock_object, 0, 0, file, line);
/* TODO: drop "owner of record" here. */
for (;;) {
/*
* See if there is more than one read lock held. If so,
* just drop one and return.
*/
x = rw->rw_lock;
if (RW_READERS(x) > 1) {
if (atomic_cmpset_rel_ptr(&rw->rw_lock, x,
x - RW_ONE_READER)) {
if (LOCK_LOG_TEST(&rw->lock_object, 0))
CTR4(KTR_LOCK,
"%s: %p succeeded %p -> %p",
__func__, rw, (void *)x,
(void *)(x - RW_ONE_READER));
break;
}
continue;
}
/*
* If there aren't any waiters for a write lock, then try
* to drop it quickly.
*/
if (!(x & RW_LOCK_WAITERS)) {
MPASS((x & ~RW_LOCK_WRITE_SPINNER) ==
RW_READERS_LOCK(1));
if (atomic_cmpset_rel_ptr(&rw->rw_lock, x,
RW_UNLOCKED)) {
if (LOCK_LOG_TEST(&rw->lock_object, 0))
CTR2(KTR_LOCK, "%s: %p last succeeded",
__func__, rw);
break;
}
continue;
}
/*
* Ok, we know we have waiters and we think we are the
* last reader, so grab the turnstile lock.
*/
turnstile_chain_lock(&rw->lock_object);
v = rw->rw_lock & (RW_LOCK_WAITERS | RW_LOCK_WRITE_SPINNER);
MPASS(v & RW_LOCK_WAITERS);
/*
* Try to drop our lock leaving the lock in a unlocked
* state.
*
* If you wanted to do explicit lock handoff you'd have to
* do it here. You'd also want to use turnstile_signal()
* and you'd have to handle the race where a higher
* priority thread blocks on the write lock before the
* thread you wakeup actually runs and have the new thread
* "steal" the lock. For now it's a lot simpler to just
* wakeup all of the waiters.
*
* As above, if we fail, then another thread might have
* acquired a read lock, so drop the turnstile lock and
* restart.
*/
x = RW_UNLOCKED;
if (v & RW_LOCK_WRITE_WAITERS) {
queue = TS_EXCLUSIVE_QUEUE;
x |= (v & RW_LOCK_READ_WAITERS);
} else
queue = TS_SHARED_QUEUE;
if (!atomic_cmpset_rel_ptr(&rw->rw_lock, RW_READERS_LOCK(1) | v,
x)) {
turnstile_chain_unlock(&rw->lock_object);
continue;
}
if (LOCK_LOG_TEST(&rw->lock_object, 0))
CTR2(KTR_LOCK, "%s: %p last succeeded with waiters",
__func__, rw);
/*
* Ok. The lock is released and all that's left is to
* wake up the waiters. Note that the lock might not be
* free anymore, but in that case the writers will just
* block again if they run before the new lock holder(s)
* release the lock.
*/
ts = turnstile_lookup(&rw->lock_object);
MPASS(ts != NULL);
turnstile_broadcast(ts, queue);
turnstile_unpend(ts, TS_SHARED_LOCK);
turnstile_chain_unlock(&rw->lock_object);
break;
}
LOCKSTAT_PROFILE_RELEASE_RWLOCK(rw__release, rw, LOCKSTAT_READER);
curthread->td_locks--;
curthread->td_rw_rlocks--;
}
