int
__rw_try_rlock(volatile uintptr_t *c, const char *file, int line)
{
struct rwlock *rw;
uintptr_t x;
if (SCHEDULER_STOPPED())
return (1);
rw = rwlock2rw(c);
KASSERT(kdb_active != 0 || !TD_IS_IDLETHREAD(curthread),
("rw_try_rlock() by idle thread %p on rwlock %s @ %s:%d",
curthread, rw->lock_object.lo_name, file, line));
for (;;) {
x = rw->rw_lock;
KASSERT(rw->rw_lock != RW_DESTROYED,
("rw_try_rlock() of destroyed rwlock @ %s:%d", file, line));
if (!(x & RW_LOCK_READ))
break;
if (atomic_cmpset_acq_ptr(&rw->rw_lock, x, x + RW_ONE_READER)) {
LOCK_LOG_TRY("RLOCK", &rw->lock_object, 0, 1, file,
line);
WITNESS_LOCK(&rw->lock_object, LOP_TRYLOCK, file, line);
curthread->td_locks++;
curthread->td_rw_rlocks++;
return (1);
}
}
LOCK_LOG_TRY("RLOCK", &rw->lock_object, 0, 0, file, line);
return (0);
}
int
sx_try_slock_(struct sx *sx, const char *file, int line)
{
uintptr_t x;
if (SCHEDULER_STOPPED())
return (1);
KASSERT(kdb_active != 0 || !TD_IS_IDLETHREAD(curthread),
("sx_try_slock() by idle thread %p on sx %s @ %s:%d",
curthread, sx->lock_object.lo_name, file, line));
for (;;) {
x = sx->sx_lock;
KASSERT(x != SX_LOCK_DESTROYED,
("sx_try_slock() of destroyed sx @ %s:%d", file, line));
if (!(x & SX_LOCK_SHARED))
break;
if (atomic_cmpset_acq_ptr(&sx->sx_lock, x, x + SX_ONE_SHARER)) {
LOCK_LOG_TRY("SLOCK", &sx->lock_object, 0, 1, file, line);
WITNESS_LOCK(&sx->lock_object, LOP_TRYLOCK, file, line);
LOCKSTAT_PROFILE_OBTAIN_RWLOCK_SUCCESS(sx__acquire,
sx, 0, 0, file, line, LOCKSTAT_READER);
curthread->td_locks++;
return (1);
}
}
LOCK_LOG_TRY("SLOCK", &sx->lock_object, 0, 0, file, line);
return (0);
}
int
__mtx_trylock_spin_flags(volatile uintptr_t *c, int opts, const char *file,
int line)
{
struct mtx *m;
if (SCHEDULER_STOPPED())
return (1);
m = mtxlock2mtx(c);
KASSERT(m->mtx_lock != MTX_DESTROYED,
("mtx_trylock_spin() of destroyed mutex @ %s:%d", file, line));
KASSERT(LOCK_CLASS(&m->lock_object) == &lock_class_mtx_spin,
("mtx_trylock_spin() of sleep mutex %s @ %s:%d",
m->lock_object.lo_name, file, line));
KASSERT((opts & MTX_RECURSE) == 0,
("mtx_trylock_spin: unsupp. opt MTX_RECURSE on mutex %s @ %s:%d\n",
m->lock_object.lo_name, file, line));
if (__mtx_trylock_spin(m, curthread, opts, file, line)) {
LOCK_LOG_TRY("LOCK", &m->lock_object, opts, 1, file, line);
WITNESS_LOCK(&m->lock_object, opts | LOP_EXCLUSIVE, file, line);
return (1);
}
LOCK_LOG_TRY("LOCK", &m->lock_object, opts, 0, file, line);
return (0);
}
int
_rw_try_rlock(struct rwlock *rw, const char *file, int line)
{
uintptr_t x;
if (SCHEDULER_STOPPED())
return (1);
for (;;) {
x = rw->rw_lock;
KASSERT(rw->rw_lock != RW_DESTROYED,
("rw_try_rlock() of destroyed rwlock @ %s:%d", file, line));
if (!(x & RW_LOCK_READ))
break;
if (atomic_cmpset_acq_ptr(&rw->rw_lock, x, x + RW_ONE_READER)) {
LOCK_LOG_TRY("RLOCK", &rw->lock_object, 0, 1, file,
line);
WITNESS_LOCK(&rw->lock_object, LOP_TRYLOCK, file, line);
curthread->td_locks++;
curthread->td_rw_rlocks++;
return (1);
}
}
LOCK_LOG_TRY("RLOCK", &rw->lock_object, 0, 0, file, line);
return (0);
}
int
sx_try_slock_(struct sx *sx, const char *file, int line)
{
uintptr_t x;
if (SCHEDULER_STOPPED())
return (1);
for (;;) {
x = sx->sx_lock;
KASSERT(x != SX_LOCK_DESTROYED,
("sx_try_slock() of destroyed sx @ %s:%d", file, line));
if (!(x & SX_LOCK_SHARED))
break;
if (atomic_cmpset_acq_ptr(&sx->sx_lock, x, x + SX_ONE_SHARER)) {
LOCK_LOG_TRY("SLOCK", &sx->lock_object, 0, 1, file, line);
WITNESS_LOCK(&sx->lock_object, LOP_TRYLOCK, file, line);
curthread->td_locks++;
return (1);
}
}
LOCK_LOG_TRY("SLOCK", &sx->lock_object, 0, 0, file, line);
return (0);
}
int
_rm_rlock_debug(struct rmlock *rm, struct rm_priotracker *tracker,
int trylock, const char *file, int line)
{
if (SCHEDULER_STOPPED())
return (1);
#ifdef INVARIANTS
if (!(rm->lock_object.lo_flags & LO_RECURSABLE) && !trylock) {
critical_enter();
KASSERT(rm_trackers_present(pcpu_find(curcpu), rm,
curthread) == 0,
("rm_rlock: recursed on non-recursive rmlock %s @ %s:%d\n",
rm->lock_object.lo_name, file, line));
critical_exit();
}
#endif
KASSERT(kdb_active != 0 || !TD_IS_IDLETHREAD(curthread),
("rm_rlock() by idle thread %p on rmlock %s @ %s:%d",
curthread, rm->lock_object.lo_name, file, line));
KASSERT(!rm_destroyed(rm),
("rm_rlock() of destroyed rmlock @ %s:%d", file, line));
if (!trylock) {
KASSERT(!rm_wowned(rm),
("rm_rlock: wlock already held for %s @ %s:%d",
rm->lock_object.lo_name, file, line));
WITNESS_CHECKORDER(&rm->lock_object, LOP_NEWORDER, file, line,
NULL);
}
if (_rm_rlock(rm, tracker, trylock)) {
if (trylock)
LOCK_LOG_TRY("RMRLOCK", &rm->lock_object, 0, 1, file,
line);
else
LOCK_LOG_LOCK("RMRLOCK", &rm->lock_object, 0, 0, file,
line);
WITNESS_LOCK(&rm->lock_object, 0, file, line);
curthread->td_locks++;
return (1);
} else if (trylock)
LOCK_LOG_TRY("RMRLOCK", &rm->lock_object, 0, 0, file, line);
return (0);
}
/*
* Try to do a non-blocking upgrade from a shared lock to an exclusive lock.
* This will only succeed if this thread holds a single shared lock.
* Return 1 if if the upgrade succeed, 0 otherwise.
*/
int
sx_try_upgrade_(struct sx *sx, const char *file, int line)
{
uintptr_t x;
int success;
if (SCHEDULER_STOPPED())
return (1);
KASSERT(sx->sx_lock != SX_LOCK_DESTROYED,
("sx_try_upgrade() of destroyed sx @ %s:%d", file, line));
_sx_assert(sx, SA_SLOCKED, file, line);
/*
* Try to switch from one shared lock to an exclusive lock. We need
* to maintain the SX_LOCK_EXCLUSIVE_WAITERS flag if set so that
* we will wake up the exclusive waiters when we drop the lock.
*/
x = sx->sx_lock & SX_LOCK_EXCLUSIVE_WAITERS;
success = atomic_cmpset_ptr(&sx->sx_lock, SX_SHARERS_LOCK(1) | x,
(uintptr_t)curthread | x);
LOCK_LOG_TRY("XUPGRADE", &sx->lock_object, 0, success, file, line);
if (success) {
WITNESS_UPGRADE(&sx->lock_object, LOP_EXCLUSIVE | LOP_TRYLOCK,
file, line);
LOCKSTAT_RECORD0(sx__upgrade, sx);
}
return (success);
}
int
__rw_try_wlock(volatile uintptr_t *c, const char *file, int line)
{
struct rwlock *rw;
int rval;
if (SCHEDULER_STOPPED())
return (1);
rw = rwlock2rw(c);
KASSERT(kdb_active != 0 || !TD_IS_IDLETHREAD(curthread),
("rw_try_wlock() by idle thread %p on rwlock %s @ %s:%d",
curthread, rw->lock_object.lo_name, file, line));
KASSERT(rw->rw_lock != RW_DESTROYED,
("rw_try_wlock() of destroyed rwlock @ %s:%d", file, line));
if (rw_wlocked(rw) &&
(rw->lock_object.lo_flags & LO_RECURSABLE) != 0) {
rw->rw_recurse++;
rval = 1;
} else
rval = atomic_cmpset_acq_ptr(&rw->rw_lock, RW_UNLOCKED,
(uintptr_t)curthread);
LOCK_LOG_TRY("WLOCK", &rw->lock_object, 0, rval, file, line);
if (rval) {
WITNESS_LOCK(&rw->lock_object, LOP_EXCLUSIVE | LOP_TRYLOCK,
file, line);
curthread->td_locks++;
}
return (rval);
}
int
sx_try_xlock_(struct sx *sx, const char *file, int line)
{
int rval;
if (SCHEDULER_STOPPED())
return (1);
KASSERT(kdb_active != 0 || !TD_IS_IDLETHREAD(curthread),
("sx_try_xlock() by idle thread %p on sx %s @ %s:%d",
curthread, sx->lock_object.lo_name, file, line));
KASSERT(sx->sx_lock != SX_LOCK_DESTROYED,
("sx_try_xlock() of destroyed sx @ %s:%d", file, line));
if (sx_xlocked(sx) &&
(sx->lock_object.lo_flags & LO_RECURSABLE) != 0) {
sx->sx_recurse++;
atomic_set_ptr(&sx->sx_lock, SX_LOCK_RECURSED);
rval = 1;
} else
rval = atomic_cmpset_acq_ptr(&sx->sx_lock, SX_LOCK_UNLOCKED,
(uintptr_t)curthread);
LOCK_LOG_TRY("XLOCK", &sx->lock_object, 0, rval, file, line);
if (rval) {
WITNESS_LOCK(&sx->lock_object, LOP_EXCLUSIVE | LOP_TRYLOCK,
file, line);
if (!sx_recursed(sx))
LOCKSTAT_PROFILE_OBTAIN_RWLOCK_SUCCESS(sx__acquire,
sx, 0, 0, file, line, LOCKSTAT_WRITER);
curthread->td_locks++;
}
return (rval);
}
int
sx_try_xlock_(struct sx *sx, const char *file, int line)
{
int rval;
if (SCHEDULER_STOPPED())
return (1);
MPASS(curthread != NULL);
KASSERT(sx->sx_lock != SX_LOCK_DESTROYED,
("sx_try_xlock() of destroyed sx @ %s:%d", file, line));
if (sx_xlocked(sx) &&
(sx->lock_object.lo_flags & LO_RECURSABLE) != 0) {
sx->sx_recurse++;
atomic_set_ptr(&sx->sx_lock, SX_LOCK_RECURSED);
rval = 1;
} else
rval = atomic_cmpset_acq_ptr(&sx->sx_lock, SX_LOCK_UNLOCKED,
(uintptr_t)curthread);
LOCK_LOG_TRY("XLOCK", &sx->lock_object, 0, rval, file, line);
if (rval) {
WITNESS_LOCK(&sx->lock_object, LOP_EXCLUSIVE | LOP_TRYLOCK,
file, line);
curthread->td_locks++;
}
return (rval);
}
int
_rw_try_wlock(struct rwlock *rw, const char *file, int line)
{
int rval;
if (SCHEDULER_STOPPED())
return (1);
KASSERT(rw->rw_lock != RW_DESTROYED,
("rw_try_wlock() of destroyed rwlock @ %s:%d", file, line));
if (rw_wlocked(rw) &&
(rw->lock_object.lo_flags & LO_RECURSABLE) != 0) {
rw->rw_recurse++;
rval = 1;
} else
rval = atomic_cmpset_acq_ptr(&rw->rw_lock, RW_UNLOCKED,
(uintptr_t)curthread);
LOCK_LOG_TRY("WLOCK", &rw->lock_object, 0, rval, file, line);
if (rval) {
WITNESS_LOCK(&rw->lock_object, LOP_EXCLUSIVE | LOP_TRYLOCK,
file, line);
curthread->td_locks++;
}
return (rval);
}
/*
* The important part of mtx_trylock{,_flags}()
* Tries to acquire lock `m.' If this function is called on a mutex that
* is already owned, it will recursively acquire the lock.
*/
int
_mtx_trylock_flags_int(struct mtx *m, int opts LOCK_FILE_LINE_ARG_DEF)
{
struct thread *td;
uintptr_t tid, v;
#ifdef LOCK_PROFILING
uint64_t waittime = 0;
int contested = 0;
#endif
int rval;
bool recursed;
td = curthread;
tid = (uintptr_t)td;
if (SCHEDULER_STOPPED_TD(td))
return (1);
KASSERT(kdb_active != 0 || !TD_IS_IDLETHREAD(td),
("mtx_trylock() by idle thread %p on sleep mutex %s @ %s:%d",
curthread, m->lock_object.lo_name, file, line));
KASSERT(m->mtx_lock != MTX_DESTROYED,
("mtx_trylock() of destroyed mutex @ %s:%d", file, line));
KASSERT(LOCK_CLASS(&m->lock_object) == &lock_class_mtx_sleep,
("mtx_trylock() of spin mutex %s @ %s:%d", m->lock_object.lo_name,
file, line));
rval = 1;
recursed = false;
v = MTX_UNOWNED;
for (;;) {
if (_mtx_obtain_lock_fetch(m, &v, tid))
break;
if (v == MTX_UNOWNED)
continue;
if (v == tid &&
((m->lock_object.lo_flags & LO_RECURSABLE) != 0 ||
(opts & MTX_RECURSE) != 0)) {
m->mtx_recurse++;
atomic_set_ptr(&m->mtx_lock, MTX_RECURSED);
recursed = true;
break;
}
rval = 0;
break;
}
opts &= ~MTX_RECURSE;
LOCK_LOG_TRY("LOCK", &m->lock_object, opts, rval, file, line);
if (rval) {
WITNESS_LOCK(&m->lock_object, opts | LOP_EXCLUSIVE | LOP_TRYLOCK,
file, line);
TD_LOCKS_INC(curthread);
if (!recursed)
LOCKSTAT_PROFILE_OBTAIN_LOCK_SUCCESS(adaptive__acquire,
m, contested, waittime, file, line);
}
return (rval);
}
int
_sx_try_slock(struct sx *sx, const char *file, int line)
{
mtx_lock(sx->sx_lock);
if (sx->sx_cnt >= 0) {
sx->sx_cnt++;
LOCK_LOG_TRY("SLOCK", &sx->sx_object, 0, 1, file, line);
WITNESS_LOCK(&sx->sx_object, LOP_TRYLOCK, file, line);
mtx_unlock(sx->sx_lock);
return (1);
} else {
LOCK_LOG_TRY("SLOCK", &sx->sx_object, 0, 0, file, line);
mtx_unlock(sx->sx_lock);
return (0);
}
}
int
_sx_try_xlock(struct sx *sx, const char *file, int line)
{
mtx_lock(sx->sx_lock);
if (sx->sx_cnt == 0) {
sx->sx_cnt--;
sx->sx_xholder = curthread;
LOCK_LOG_TRY("XLOCK", &sx->sx_object, 0, 1, file, line);
WITNESS_LOCK(&sx->sx_object, LOP_EXCLUSIVE | LOP_TRYLOCK, file,
line);
mtx_unlock(sx->sx_lock);
return (1);
} else {
LOCK_LOG_TRY("XLOCK", &sx->sx_object, 0, 0, file, line);
mtx_unlock(sx->sx_lock);
return (0);
}
}
int
_sx_try_upgrade(struct sx *sx, const char *file, int line)
{
_sx_assert(sx, SX_SLOCKED, file, line);
mtx_lock(sx->sx_lock);
if (sx->sx_cnt == 1) {
sx->sx_cnt = -1;
sx->sx_xholder = curthread;
LOCK_LOG_TRY("XUPGRADE", &sx->sx_object, 0, 1, file, line);
WITNESS_UPGRADE(&sx->sx_object, LOP_EXCLUSIVE | LOP_TRYLOCK,
file, line);
mtx_unlock(sx->sx_lock);
return (1);
} else {
LOCK_LOG_TRY("XUPGRADE", &sx->sx_object, 0, 0, file, line);
mtx_unlock(sx->sx_lock);
return (0);
}
}
/*
* The important part of mtx_trylock{,_flags}()
* Tries to acquire lock `m.' If this function is called on a mutex that
* is already owned, it will recursively acquire the lock.
*/
int
_mtx_trylock_flags_(volatile uintptr_t *c, int opts, const char *file, int line)
{
struct mtx *m;
#ifdef LOCK_PROFILING
uint64_t waittime = 0;
int contested = 0;
#endif
int rval;
if (SCHEDULER_STOPPED())
return (1);
m = mtxlock2mtx(c);
KASSERT(kdb_active != 0 || !TD_IS_IDLETHREAD(curthread),
("mtx_trylock() by idle thread %p on sleep mutex %s @ %s:%d",
curthread, m->lock_object.lo_name, file, line));
KASSERT(m->mtx_lock != MTX_DESTROYED,
("mtx_trylock() of destroyed mutex @ %s:%d", file, line));
KASSERT(LOCK_CLASS(&m->lock_object) == &lock_class_mtx_sleep,
("mtx_trylock() of spin mutex %s @ %s:%d", m->lock_object.lo_name,
file, line));
if (mtx_owned(m) && ((m->lock_object.lo_flags & LO_RECURSABLE) != 0 ||
(opts & MTX_RECURSE) != 0)) {
m->mtx_recurse++;
atomic_set_ptr(&m->mtx_lock, MTX_RECURSED);
rval = 1;
} else
rval = _mtx_obtain_lock(m, (uintptr_t)curthread);
opts &= ~MTX_RECURSE;
LOCK_LOG_TRY("LOCK", &m->lock_object, opts, rval, file, line);
if (rval) {
WITNESS_LOCK(&m->lock_object, opts | LOP_EXCLUSIVE | LOP_TRYLOCK,
file, line);
TD_LOCKS_INC(curthread);
if (m->mtx_recurse == 0)
LOCKSTAT_PROFILE_OBTAIN_LOCK_SUCCESS(adaptive__acquire,
m, contested, waittime, file, line);
}
return (rval);
}
/*
* The important part of mtx_trylock{,_flags}()
* Tries to acquire lock `m.' If this function is called on a mutex that
* is already owned, it will recursively acquire the lock.
*/
int
_mtx_trylock(struct mtx *m, int opts, const char *file, int line)
{
#ifdef LOCK_PROFILING
uint64_t waittime = 0;
int contested = 0;
#endif
int rval;
MPASS(curthread != NULL);
KASSERT(m->mtx_lock != MTX_DESTROYED,
("mtx_trylock() of destroyed mutex @ %s:%d", file, line));
KASSERT(LOCK_CLASS(&m->lock_object) == &lock_class_mtx_sleep,
("mtx_trylock() of spin mutex %s @ %s:%d", m->lock_object.lo_name,
file, line));
if (mtx_owned(m) && (m->lock_object.lo_flags & LO_RECURSABLE) != 0) {
m->mtx_recurse++;
atomic_set_ptr(&m->mtx_lock, MTX_RECURSED);
rval = 1;
} else
rval = _obtain_lock(m, (uintptr_t)curthread);
LOCK_LOG_TRY("LOCK", &m->lock_object, opts, rval, file, line);
if (rval) {
WITNESS_LOCK(&m->lock_object, opts | LOP_EXCLUSIVE | LOP_TRYLOCK,
file, line);
curthread->td_locks++;
if (m->mtx_recurse == 0)
LOCKSTAT_PROFILE_OBTAIN_LOCK_SUCCESS(LS_MTX_LOCK_ACQUIRE,
m, contested, waittime, file, line);
}
return (rval);
}
/*
* Attempt to do a non-blocking upgrade from a read lock to a write
* lock. This will only succeed if this thread holds a single read
* lock. Returns true if the upgrade succeeded and false otherwise.
*/
int
__rw_try_upgrade(volatile uintptr_t *c, const char *file, int line)
{
struct rwlock *rw;
uintptr_t v, x, tid;
struct turnstile *ts;
int success;
if (SCHEDULER_STOPPED())
return (1);
rw = rwlock2rw(c);
KASSERT(rw->rw_lock != RW_DESTROYED,
("rw_try_upgrade() of destroyed rwlock @ %s:%d", file, line));
__rw_assert(c, RA_RLOCKED, file, line);
/*
* Attempt to switch from one reader to a writer. If there
* are any write waiters, then we will have to lock the
* turnstile first to prevent races with another writer
* calling turnstile_wait() before we have claimed this
* turnstile. So, do the simple case of no waiters first.
*/
tid = (uintptr_t)curthread;
success = 0;
for (;;) {
v = rw->rw_lock;
if (RW_READERS(v) > 1)
break;
if (!(v & RW_LOCK_WAITERS)) {
success = atomic_cmpset_ptr(&rw->rw_lock, v, tid);
if (!success)
continue;
break;
}
/*
* Ok, we think we have waiters, so lock the turnstile.
*/
ts = turnstile_trywait(&rw->lock_object);
v = rw->rw_lock;
if (RW_READERS(v) > 1) {
turnstile_cancel(ts);
break;
}
/*
* Try to switch from one reader to a writer again. This time
* we honor the current state of the waiters flags.
* If we obtain the lock with the flags set, then claim
* ownership of the turnstile.
*/
x = rw->rw_lock & RW_LOCK_WAITERS;
success = atomic_cmpset_ptr(&rw->rw_lock, v, tid | x);
if (success) {
if (x)
turnstile_claim(ts);
else
turnstile_cancel(ts);
break;
}
turnstile_cancel(ts);
}
LOCK_LOG_TRY("WUPGRADE", &rw->lock_object, 0, success, file, line);
if (success) {
curthread->td_rw_rlocks--;
WITNESS_UPGRADE(&rw->lock_object, LOP_EXCLUSIVE | LOP_TRYLOCK,
file, line);
LOCKSTAT_RECORD0(rw__upgrade, rw);
}
return (success);
}
