aboutsummaryrefslogtreecommitdiffstats
path: root/erts/emulator/beam/erl_process_lock.c
diff options
context:
space:
mode:
Diffstat (limited to 'erts/emulator/beam/erl_process_lock.c')
-rw-r--r--erts/emulator/beam/erl_process_lock.c168
1 files changed, 38 insertions, 130 deletions
diff --git a/erts/emulator/beam/erl_process_lock.c b/erts/emulator/beam/erl_process_lock.c
index 83272aab42..aabeeca87a 100644
--- a/erts/emulator/beam/erl_process_lock.c
+++ b/erts/emulator/beam/erl_process_lock.c
@@ -92,16 +92,6 @@ static void check_queue(erts_proc_lock_t *lck);
#error "The size of the 'uflgs' field of the erts_tse_t type is too small"
#endif
-struct erts_proc_lock_queues_t_ {
- erts_proc_lock_queues_t *next;
- erts_tse_t *queue[ERTS_PROC_LOCK_MAX_BIT+1];
-};
-
-static erts_proc_lock_queues_t zeroqs = {0};
-
-static erts_smp_spinlock_t qs_lock;
-static erts_proc_lock_queues_t *queue_free_list;
-
static int proc_lock_spin_count;
static int aux_thr_proc_lock_spin_count;
@@ -134,8 +124,6 @@ erts_init_proc_lock(int cpus)
#endif
}
#if ERTS_PROC_LOCK_OWN_IMPL
- erts_smp_spinlock_init(&qs_lock, "proc_lck_qs_alloc");
- queue_free_list = NULL;
erts_thr_install_exit_handler(cleanup_tse);
if (cpus > 1) {
proc_lock_spin_count = ERTS_PROC_LOCK_SPIN_COUNT_BASE;
@@ -165,16 +153,7 @@ erts_init_proc_lock(int cpus)
#if ERTS_PROC_LOCK_OWN_IMPL
#ifdef ERTS_ENABLE_LOCK_CHECK
-static void
-check_unused_tse(erts_tse_t *wtr)
-{
- int i;
- erts_proc_lock_queues_t *queues = wtr->udata;
- ERTS_LC_ASSERT(wtr->uflgs == 0);
- for (i = 0; i <= ERTS_PROC_LOCK_MAX_BIT; i++)
- ERTS_LC_ASSERT(!queues->queue[i]);
-}
-#define CHECK_UNUSED_TSE(W) check_unused_tse((W))
+#define CHECK_UNUSED_TSE(W) ERTS_LC_ASSERT((W)->uflgs == 0)
#else
#define CHECK_UNUSED_TSE(W)
#endif
@@ -183,49 +162,14 @@ static ERTS_INLINE erts_tse_t *
tse_fetch(erts_pix_lock_t *pix_lock)
{
erts_tse_t *tse = erts_tse_fetch();
- if (!tse->udata) {
- erts_proc_lock_queues_t *qs;
-#if ERTS_PROC_LOCK_SPINLOCK_IMPL && !ERTS_PROC_LOCK_ATOMIC_IMPL
- if (pix_lock)
- erts_pix_unlock(pix_lock);
-#endif
- erts_smp_spin_lock(&qs_lock);
- qs = queue_free_list;
- if (qs) {
- queue_free_list = queue_free_list->next;
- erts_smp_spin_unlock(&qs_lock);
- }
- else {
- erts_smp_spin_unlock(&qs_lock);
- qs = erts_alloc(ERTS_ALC_T_PROC_LCK_QS,
- sizeof(erts_proc_lock_queues_t));
- sys_memcpy((void *) qs,
- (void *) &zeroqs,
- sizeof(erts_proc_lock_queues_t));
- }
- tse->udata = qs;
-#if ERTS_PROC_LOCK_SPINLOCK_IMPL && !ERTS_PROC_LOCK_ATOMIC_IMPL
- if (pix_lock)
- erts_pix_lock(pix_lock);
-#endif
- }
tse->uflgs = 0;
return tse;
}
static ERTS_INLINE void
-tse_return(erts_tse_t *tse, int force_free_q)
+tse_return(erts_tse_t *tse)
{
CHECK_UNUSED_TSE(tse);
- if (force_free_q || erts_tse_is_tmp(tse)) {
- erts_proc_lock_queues_t *qs = tse->udata;
- ASSERT(qs);
- erts_smp_spin_lock(&qs_lock);
- qs->next = queue_free_list;
- queue_free_list = qs;
- erts_smp_spin_unlock(&qs_lock);
- tse->udata = NULL;
- }
erts_tse_return(tse);
}
@@ -233,55 +177,49 @@ static void
cleanup_tse(void)
{
erts_tse_t *tse = erts_tse_fetch();
- if (tse) {
- if (tse->udata)
- tse_return(tse, 1);
- else
- erts_tse_return(tse);
- }
+ if (tse)
+ erts_tse_return(tse);
}
/*
* Waiters are queued in a circular double linked list;
- * where qs->queue[lock_ix] is the first waiter in queue, and
- * qs->queue[lock_ix]->prev is the last waiter in queue.
+ * where lck->queue[lock_ix] is the first waiter in queue, and
+ * lck->queue[lock_ix]->prev is the last waiter in queue.
*/
static ERTS_INLINE void
-enqueue_waiter(erts_proc_lock_queues_t *qs,
- int ix,
- erts_tse_t *wtr)
+enqueue_waiter(erts_proc_lock_t *lck, int ix, erts_tse_t *wtr)
{
- if (!qs->queue[ix]) {
- qs->queue[ix] = wtr;
+ if (!lck->queue[ix]) {
+ lck->queue[ix] = wtr;
wtr->next = wtr;
wtr->prev = wtr;
}
else {
- ERTS_LC_ASSERT(qs->queue[ix]->next && qs->queue[ix]->prev);
- wtr->next = qs->queue[ix];
- wtr->prev = qs->queue[ix]->prev;
+ ERTS_LC_ASSERT(lck->queue[ix]->next && lck->queue[ix]->prev);
+ wtr->next = lck->queue[ix];
+ wtr->prev = lck->queue[ix]->prev;
wtr->prev->next = wtr;
- qs->queue[ix]->prev = wtr;
+ lck->queue[ix]->prev = wtr;
}
}
static erts_tse_t *
-dequeue_waiter(erts_proc_lock_queues_t *qs, int ix)
+dequeue_waiter(erts_proc_lock_t *lck, int ix)
{
- erts_tse_t *wtr = qs->queue[ix];
- ERTS_LC_ASSERT(qs->queue[ix]);
+ erts_tse_t *wtr = lck->queue[ix];
+ ERTS_LC_ASSERT(lck->queue[ix]);
if (wtr->next == wtr) {
- ERTS_LC_ASSERT(qs->queue[ix]->prev == wtr);
- qs->queue[ix] = NULL;
+ ERTS_LC_ASSERT(lck->queue[ix]->prev == wtr);
+ lck->queue[ix] = NULL;
}
else {
ERTS_LC_ASSERT(wtr->next != wtr);
ERTS_LC_ASSERT(wtr->prev != wtr);
wtr->next->prev = wtr->prev;
wtr->prev->next = wtr->next;
- qs->queue[ix] = wtr->next;
+ lck->queue[ix] = wtr->next;
}
return wtr;
}
@@ -302,19 +240,18 @@ try_aquire(erts_proc_lock_t *lck, erts_tse_t *wtr)
ErtsProcLocks locks = wtr->uflgs;
int lock_no;
- ERTS_LC_ASSERT(lck->queues);
ERTS_LC_ASSERT(got_locks != locks);
for (lock_no = 0; lock_no <= ERTS_PROC_LOCK_MAX_BIT; lock_no++) {
ErtsProcLocks lock = ((ErtsProcLocks) 1) << lock_no;
if (locks & lock) {
ErtsProcLocks wflg, old_lflgs;
- if (lck->queues->queue[lock_no]) {
+ if (lck->queue[lock_no]) {
/* Others already waiting */
enqueue:
ERTS_LC_ASSERT(ERTS_PROC_LOCK_FLGS_READ_(lck)
& (lock << ERTS_PROC_LOCK_WAITER_SHIFT));
- enqueue_waiter(lck->queues, lock_no, wtr);
+ enqueue_waiter(lck, lock_no, wtr);
break;
}
wflg = lock << ERTS_PROC_LOCK_WAITER_SHIFT;
@@ -366,7 +303,6 @@ transfer_locks(Process *p,
for (lock_no = 0; tlocks && lock_no <= ERTS_PROC_LOCK_MAX_BIT; lock_no++) {
ErtsProcLocks lock = ((ErtsProcLocks) 1) << lock_no;
if (tlocks & lock) {
- erts_proc_lock_queues_t *qs = p->lock.queues;
/* Transfer lock */
#ifdef ERTS_ENABLE_LOCK_CHECK
tlocks &= ~lock;
@@ -374,9 +310,9 @@ transfer_locks(Process *p,
ERTS_LC_ASSERT(ERTS_PROC_LOCK_FLGS_READ_(&p->lock)
& (lock << ERTS_PROC_LOCK_WAITER_SHIFT));
transferred++;
- wtr = dequeue_waiter(qs, lock_no);
+ wtr = dequeue_waiter(&p->lock, lock_no);
ERTS_LC_ASSERT(wtr);
- if (!qs->queue[lock_no])
+ if (!p->lock.queue[lock_no])
unset_waiter |= lock;
ERTS_LC_ASSERT(wtr->uflgs & lock);
wtr->uflgs &= ~lock;
@@ -465,7 +401,6 @@ wait_for_locks(Process *p,
{
erts_pix_lock_t *pix_lock = pixlck ? pixlck : ERTS_PID2PIXLOCK(p->id);
erts_tse_t *wtr;
- erts_proc_lock_queues_t *qs;
/* Acquire a waiter object on which this thread can wait. */
wtr = tse_fetch(pix_lock);
@@ -481,18 +416,6 @@ wait_for_locks(Process *p,
ERTS_LC_ASSERT(erts_lc_pix_lock_is_locked(pix_lock));
- qs = wtr->udata;
- ASSERT(qs);
- /* Provide the process with waiter queues, if it doesn't have one. */
- if (!p->lock.queues) {
- qs->next = NULL;
- p->lock.queues = qs;
- }
- else {
- qs->next = p->lock.queues->next;
- p->lock.queues->next = qs;
- }
-
#ifdef ERTS_PROC_LOCK_HARD_DEBUG
check_queue(&p->lock);
#endif
@@ -506,7 +429,9 @@ wait_for_locks(Process *p,
check_queue(&p->lock);
#endif
- if (wtr->uflgs) {
+ if (wtr->uflgs == 0)
+ erts_pix_unlock(pix_lock);
+ else {
/* We didn't get them all; need to wait... */
ASSERT((wtr->uflgs & ~ERTS_PROC_LOCKS_ALL) == 0);
@@ -531,28 +456,12 @@ wait_for_locks(Process *p,
} while (res != 0);
}
- erts_pix_lock(pix_lock);
-
ASSERT(wtr->uflgs == 0);
}
- /* Recover some queues to store in the waiter. */
- ERTS_LC_ASSERT(p->lock.queues);
- if (p->lock.queues->next) {
- qs = p->lock.queues->next;
- p->lock.queues->next = qs->next;
- }
- else {
- qs = p->lock.queues;
- p->lock.queues = NULL;
- }
- wtr->udata = qs;
-
- erts_pix_unlock(pix_lock);
-
ERTS_LC_ASSERT(locks == (ERTS_PROC_LOCK_FLGS_READ_(&p->lock) & locks));
- tse_return(wtr, 0);
+ tse_return(wtr);
}
/*
@@ -659,7 +568,7 @@ void
erts_proc_lock_prepare_proc_lock_waiter(void)
{
#if ERTS_PROC_LOCK_OWN_IMPL
- tse_return(tse_fetch(NULL), 0);
+ tse_return(tse_fetch(NULL));
#endif
}
@@ -1089,6 +998,7 @@ void
erts_proc_lock_init(Process *p)
{
#if ERTS_PROC_LOCK_OWN_IMPL
+ int i;
/* We always start with all locks locked */
#if ERTS_PROC_LOCK_ATOMIC_IMPL
erts_smp_atomic32_init_nob(&p->lock.flags,
@@ -1096,7 +1006,8 @@ erts_proc_lock_init(Process *p)
#else
p->lock.flags = ERTS_PROC_LOCKS_ALL;
#endif
- p->lock.queues = NULL;
+ for (i = 0; i <= ERTS_PROC_LOCK_MAX_BIT; i++)
+ p->lock.queue[i] = NULL;
#ifdef ERTS_ENABLE_LOCK_CHECK
erts_proc_lc_trylock(p, ERTS_PROC_LOCKS_ALL, 1);
#endif
@@ -1124,11 +1035,8 @@ erts_proc_lock_init(Process *p)
#endif
erts_atomic32_init_nob(&p->lock.refc, 1);
#ifdef ERTS_PROC_LOCK_DEBUG
- {
- int i;
- for (i = 0; i <= ERTS_PROC_LOCK_MAX_BIT; i++)
- erts_smp_atomic32_init_nob(&p->lock.locked[i], (erts_aint32_t) 1);
- }
+ for (i = 0; i <= ERTS_PROC_LOCK_MAX_BIT; i++)
+ erts_smp_atomic32_init_nob(&p->lock.locked[i], (erts_aint32_t) 1);
#endif
#ifdef ERTS_ENABLE_LOCK_COUNT
erts_lcnt_proc_lock_init(p);
@@ -1701,21 +1609,21 @@ check_queue(erts_proc_lock_t *lck)
if (lflgs & wtr) {
int n;
erts_tse_t *wtr;
- ERTS_LC_ASSERT(lck->queues && lck->queues->queue[lock_no]);
- wtr = lck->queues->queue[lock_no];
+ ERTS_LC_ASSERT(lck->queue[lock_no]);
+ wtr = lck->queue[lock_no];
n = 0;
do {
wtr = wtr->next;
n++;
- } while (wtr != lck->queues->queue[lock_no]);
+ } while (wtr != lck->queue[lock_no]);
do {
wtr = wtr->prev;
n--;
- } while (wtr != lck->queues->queue[lock_no]);
+ } while (wtr != lck->queue[lock_no]);
ERTS_LC_ASSERT(n == 0);
}
else {
- ERTS_LC_ASSERT(!lck->queues || !lck->queues->queue[lock_no]);
+ ERTS_LC_ASSERT(!lck->queue[lock_no]);
}
}
}