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
__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_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
__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);
}
/*
* Function versions of the inlined __mtx_* macros. These are used by
* modules and can also be called from assembly language if needed.
*/
void
__mtx_lock_flags(volatile uintptr_t *c, int opts, const char *file, int line)
{
struct mtx *m;
if (SCHEDULER_STOPPED())
return;
m = mtxlock2mtx(c);
KASSERT(kdb_active != 0 || !TD_IS_IDLETHREAD(curthread),
("mtx_lock() 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_lock() of destroyed mutex @ %s:%d", file, line));
KASSERT(LOCK_CLASS(&m->lock_object) == &lock_class_mtx_sleep,
("mtx_lock() of spin mutex %s @ %s:%d", m->lock_object.lo_name,
file, line));
WITNESS_CHECKORDER(&m->lock_object, (opts & ~MTX_RECURSE) |
LOP_NEWORDER | LOP_EXCLUSIVE, file, line, NULL);
__mtx_lock(m, curthread, opts, file, line);
LOCK_LOG_LOCK("LOCK", &m->lock_object, opts, m->mtx_recurse, file,
line);
WITNESS_LOCK(&m->lock_object, (opts & ~MTX_RECURSE) | LOP_EXCLUSIVE,
file, line);
TD_LOCKS_INC(curthread);
}
/*
* 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);
}
/*
* Function versions of the inlined __mtx_* macros. These are used by
* modules and can also be called from assembly language if needed.
*/
void
__mtx_lock_flags(volatile uintptr_t *c, int opts, const char *file, int line)
{
struct mtx *m;
uintptr_t tid, v;
m = mtxlock2mtx(c);
KASSERT(kdb_active != 0 || SCHEDULER_STOPPED() ||
!TD_IS_IDLETHREAD(curthread),
("mtx_lock() 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_lock() of destroyed mutex @ %s:%d", file, line));
KASSERT(LOCK_CLASS(&m->lock_object) == &lock_class_mtx_sleep,
("mtx_lock() of spin mutex %s @ %s:%d", m->lock_object.lo_name,
file, line));
WITNESS_CHECKORDER(&m->lock_object, (opts & ~MTX_RECURSE) |
LOP_NEWORDER | LOP_EXCLUSIVE, file, line, NULL);
tid = (uintptr_t)curthread;
v = MTX_UNOWNED;
if (!_mtx_obtain_lock_fetch(m, &v, tid))
_mtx_lock_sleep(m, v, opts, file, line);
else
LOCKSTAT_PROFILE_OBTAIN_LOCK_SUCCESS(adaptive__acquire,
m, 0, 0, file, line);
LOCK_LOG_LOCK("LOCK", &m->lock_object, opts, m->mtx_recurse, file,
line);
WITNESS_LOCK(&m->lock_object, (opts & ~MTX_RECURSE) | LOP_EXCLUSIVE,
file, line);
TD_LOCKS_INC(curthread);
}
void
_rm_wlock_debug(struct rmlock *rm, const char *file, int line)
{
if (SCHEDULER_STOPPED())
return;
KASSERT(kdb_active != 0 || !TD_IS_IDLETHREAD(curthread),
("rm_wlock() by idle thread %p on rmlock %s @ %s:%d",
curthread, rm->lock_object.lo_name, file, line));
KASSERT(!rm_destroyed(rm),
("rm_wlock() of destroyed rmlock @ %s:%d", file, line));
_rm_assert(rm, RA_UNLOCKED, file, line);
WITNESS_CHECKORDER(&rm->lock_object, LOP_NEWORDER | LOP_EXCLUSIVE,
file, line, NULL);
_rm_wlock(rm);
LOCK_LOG_LOCK("RMWLOCK", &rm->lock_object, 0, 0, file, line);
WITNESS_LOCK(&rm->lock_object, LOP_EXCLUSIVE, file, line);
curthread->td_locks++;
}
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);
}
/*
* 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);
}
void
_rw_wlock(struct rwlock *rw, const char *file, int line)
{
if (SCHEDULER_STOPPED())
return;
KASSERT(!TD_IS_IDLETHREAD(curthread),
("rw_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_wlock() of destroyed rwlock @ %s:%d", file, line));
WITNESS_CHECKORDER(&rw->lock_object, LOP_NEWORDER | LOP_EXCLUSIVE, file,
line, NULL);
__rw_wlock(rw, curthread, file, line);
LOCK_LOG_LOCK("WLOCK", &rw->lock_object, 0, rw->rw_recurse, file, line);
WITNESS_LOCK(&rw->lock_object, LOP_EXCLUSIVE, file, line);
curthread->td_locks++;
}
int
_sx_slock(struct sx *sx, int opts, const char *file, int line)
{
int error = 0;
if (SCHEDULER_STOPPED())
return (0);
KASSERT(kdb_active != 0 || !TD_IS_IDLETHREAD(curthread),
("sx_slock() 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_slock() of destroyed sx @ %s:%d", file, line));
WITNESS_CHECKORDER(&sx->lock_object, LOP_NEWORDER, file, line, NULL);
error = __sx_slock(sx, opts, file, line);
if (!error) {
LOCK_LOG_LOCK("SLOCK", &sx->lock_object, 0, 0, file, line);
WITNESS_LOCK(&sx->lock_object, 0, file, line);
curthread->td_locks++;
}
return (error);
}
void
__rw_rlock(volatile uintptr_t *c, const char *file, int line)
{
struct rwlock *rw;
struct turnstile *ts;
#ifdef ADAPTIVE_RWLOCKS
volatile struct thread *owner;
int spintries = 0;
int i;
#endif
#ifdef LOCK_PROFILING
uint64_t waittime = 0;
int contested = 0;
#endif
uintptr_t v;
#ifdef KDTRACE_HOOKS
uintptr_t state;
uint64_t spin_cnt = 0;
uint64_t sleep_cnt = 0;
int64_t sleep_time = 0;
int64_t all_time = 0;
#endif
if (SCHEDULER_STOPPED())
return;
rw = rwlock2rw(c);
KASSERT(kdb_active != 0 || !TD_IS_IDLETHREAD(curthread),
("rw_rlock() by idle thread %p on rwlock %s @ %s:%d",
curthread, rw->lock_object.lo_name, file, line));
KASSERT(rw->rw_lock != RW_DESTROYED,
("rw_rlock() of destroyed rwlock @ %s:%d", file, line));
KASSERT(rw_wowner(rw) != curthread,
("rw_rlock: wlock already held for %s @ %s:%d",
rw->lock_object.lo_name, file, line));
WITNESS_CHECKORDER(&rw->lock_object, LOP_NEWORDER, file, line, NULL);
#ifdef KDTRACE_HOOKS
all_time -= lockstat_nsecs(&rw->lock_object);
state = rw->rw_lock;
#endif
for (;;) {
/*
* Handle the easy case. If no other thread has a write
* lock, then try to bump up the count of read locks. Note
* that we have to preserve the current state of the
* RW_LOCK_WRITE_WAITERS flag. If we fail to acquire a
* read lock, then rw_lock must have changed, so restart
* the loop. Note that this handles the case of a
* completely unlocked rwlock since such a lock is encoded
* as a read lock with no waiters.
*/
v = rw->rw_lock;
if (RW_CAN_READ(v)) {
/*
* The RW_LOCK_READ_WAITERS flag should only be set
* if the lock has been unlocked and write waiters
* were present.
*/
if (atomic_cmpset_acq_ptr(&rw->rw_lock, v,
v + RW_ONE_READER)) {
if (LOCK_LOG_TEST(&rw->lock_object, 0))
CTR4(KTR_LOCK,
"%s: %p succeed %p -> %p", __func__,
rw, (void *)v,
(void *)(v + RW_ONE_READER));
break;
}
continue;
}
#ifdef KDTRACE_HOOKS
spin_cnt++;
#endif
#ifdef HWPMC_HOOKS
PMC_SOFT_CALL( , , lock, failed);
#endif
lock_profile_obtain_lock_failed(&rw->lock_object,
&contested, &waittime);
#ifdef ADAPTIVE_RWLOCKS
/*
* If the owner is running on another CPU, spin until
* the owner stops running or the state of the lock
* changes.
*/
if ((v & RW_LOCK_READ) == 0) {
owner = (struct thread *)RW_OWNER(v);
if (TD_IS_RUNNING(owner)) {
if (LOCK_LOG_TEST(&rw->lock_object, 0))
CTR3(KTR_LOCK,
"%s: spinning on %p held by %p",
__func__, rw, owner);
KTR_STATE1(KTR_SCHED, "thread",
sched_tdname(curthread), "spinning",
"lockname:\"%s\"", rw->lock_object.lo_name);
while ((struct thread*)RW_OWNER(rw->rw_lock) ==
owner && TD_IS_RUNNING(owner)) {
cpu_spinwait();
#ifdef KDTRACE_HOOKS
spin_cnt++;
#endif
}
KTR_STATE0(KTR_SCHED, "thread",
sched_tdname(curthread), "running");
continue;
}
} else if (spintries < rowner_retries) {
spintries++;
KTR_STATE1(KTR_SCHED, "thread", sched_tdname(curthread),
"spinning", "lockname:\"%s\"",
rw->lock_object.lo_name);
for (i = 0; i < rowner_loops; i++) {
v = rw->rw_lock;
if ((v & RW_LOCK_READ) == 0 || RW_CAN_READ(v))
break;
cpu_spinwait();
}
#ifdef KDTRACE_HOOKS
spin_cnt += rowner_loops - i;
#endif
KTR_STATE0(KTR_SCHED, "thread", sched_tdname(curthread),
"running");
if (i != rowner_loops)
continue;
}
#endif
/*
* Okay, now it's the hard case. Some other thread already
* has a write lock or there are write waiters present,
* acquire the turnstile lock so we can begin the process
* of blocking.
*/
ts = turnstile_trywait(&rw->lock_object);
/*
* The lock might have been released while we spun, so
* recheck its state and restart the loop if needed.
*/
v = rw->rw_lock;
if (RW_CAN_READ(v)) {
turnstile_cancel(ts);
continue;
}
#ifdef ADAPTIVE_RWLOCKS
/*
* The current lock owner might have started executing
* on another CPU (or the lock could have changed
* owners) while we were waiting on the turnstile
* chain lock. If so, drop the turnstile lock and try
* again.
*/
if ((v & RW_LOCK_READ) == 0) {
owner = (struct thread *)RW_OWNER(v);
if (TD_IS_RUNNING(owner)) {
turnstile_cancel(ts);
continue;
}
}
#endif
/*
* The lock is held in write mode or it already has waiters.
*/
MPASS(!RW_CAN_READ(v));
/*
* If the RW_LOCK_READ_WAITERS flag is already set, then
* we can go ahead and block. If it is not set then try
* to set it. If we fail to set it drop the turnstile
* lock and restart the loop.
*/
if (!(v & RW_LOCK_READ_WAITERS)) {
if (!atomic_cmpset_ptr(&rw->rw_lock, v,
v | RW_LOCK_READ_WAITERS)) {
turnstile_cancel(ts);
continue;
}
if (LOCK_LOG_TEST(&rw->lock_object, 0))
CTR2(KTR_LOCK, "%s: %p set read waiters flag",
__func__, rw);
}
/*
* We were unable to acquire the lock and the read waiters
* flag is set, so we must block on the turnstile.
*/
if (LOCK_LOG_TEST(&rw->lock_object, 0))
CTR2(KTR_LOCK, "%s: %p blocking on turnstile", __func__,
rw);
#ifdef KDTRACE_HOOKS
sleep_time -= lockstat_nsecs(&rw->lock_object);
#endif
turnstile_wait(ts, rw_owner(rw), TS_SHARED_QUEUE);
#ifdef KDTRACE_HOOKS
sleep_time += lockstat_nsecs(&rw->lock_object);
sleep_cnt++;
#endif
if (LOCK_LOG_TEST(&rw->lock_object, 0))
CTR2(KTR_LOCK, "%s: %p resuming from turnstile",
__func__, rw);
}
#ifdef KDTRACE_HOOKS
all_time += lockstat_nsecs(&rw->lock_object);
if (sleep_time)
LOCKSTAT_RECORD4(rw__block, rw, sleep_time,
LOCKSTAT_READER, (state & RW_LOCK_READ) == 0,
(state & RW_LOCK_READ) == 0 ? 0 : RW_READERS(state));
/* Record only the loops spinning and not sleeping. */
if (spin_cnt > sleep_cnt)
LOCKSTAT_RECORD4(rw__spin, rw, all_time - sleep_time,
LOCKSTAT_READER, (state & RW_LOCK_READ) == 0,
(state & RW_LOCK_READ) == 0 ? 0 : RW_READERS(state));
#endif
/*
* TODO: acquire "owner of record" here. Here be turnstile dragons
* however. turnstiles don't like owners changing between calls to
* turnstile_wait() currently.
*/
LOCKSTAT_PROFILE_OBTAIN_RWLOCK_SUCCESS(rw__acquire, rw, contested,
waittime, file, line, LOCKSTAT_READER);
LOCK_LOG_LOCK("RLOCK", &rw->lock_object, 0, 0, file, line);
WITNESS_LOCK(&rw->lock_object, 0, file, line);
curthread->td_locks++;
curthread->td_rw_rlocks++;
}
