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-rw-r--r--erts/emulator/beam/time.c291
1 files changed, 106 insertions, 185 deletions
diff --git a/erts/emulator/beam/time.c b/erts/emulator/beam/time.c
index 53d39aef0e..a00faff912 100644
--- a/erts/emulator/beam/time.c
+++ b/erts/emulator/beam/time.c
@@ -1,7 +1,7 @@
/*
* %CopyrightBegin%
*
- * Copyright Ericsson AB 1996-2009. All Rights Reserved.
+ * Copyright Ericsson AB 1996-2011. All Rights Reserved.
*
* The contents of this file are subject to the Erlang Public License,
* Version 1.1, (the "License"); you may not use this file except in
@@ -99,80 +99,37 @@ static erts_smp_mtx_t tiw_lock;
static ErlTimer** tiw; /* the timing wheel, allocated in init_time() */
static Uint tiw_pos; /* current position in wheel */
static Uint tiw_nto; /* number of timeouts in wheel */
+static Uint tiw_min;
+static ErlTimer *tiw_min_ptr;
/* END tiw_lock protected variables */
/* Actual interval time chosen by sys_init_time() */
static int itime; /* Constant after init */
-#if defined(ERTS_TIMER_THREAD)
-static SysTimeval time_start; /* start of current time interval */
-static long ticks_end; /* time_start+ticks_end == time_wakeup */
-static long ticks_latest; /* delta from time_start at latest time update*/
-
-static ERTS_INLINE long time_gettimeofday(SysTimeval *now)
-{
- long elapsed;
-
- erts_get_timeval(now);
- now->tv_usec = 1000 * (now->tv_usec / 1000); /* ms resolution */
- elapsed = (1000 * (now->tv_sec - time_start.tv_sec) +
- (now->tv_usec - time_start.tv_usec) / 1000);
- // elapsed /= CLOCK_RESOLUTION;
- return elapsed;
-}
-
-static long do_time_update(void)
-{
- SysTimeval now;
- long elapsed;
-
- elapsed = time_gettimeofday(&now);
- ticks_latest = elapsed;
- return elapsed;
-}
-
-static ERTS_INLINE long do_time_read(void)
-{
- return ticks_latest;
-}
-
-static long do_time_reset(void)
-{
- SysTimeval now;
- long elapsed;
-
- elapsed = time_gettimeofday(&now);
- time_start = now;
- ticks_end = LONG_MAX;
- ticks_latest = 0;
- return elapsed;
-}
-
-static ERTS_INLINE void do_time_init(void)
-{
- (void)do_time_reset();
-}
-
-#else
erts_smp_atomic_t do_time; /* set at clock interrupt */
-static ERTS_INLINE long do_time_read(void) { return erts_smp_atomic_read(&do_time); }
-static ERTS_INLINE long do_time_update(void) { return do_time_read(); }
+static ERTS_INLINE erts_aint_t do_time_read(void) { return erts_smp_atomic_read(&do_time); }
+static ERTS_INLINE erts_aint_t do_time_update(void) { return do_time_read(); }
static ERTS_INLINE void do_time_init(void) { erts_smp_atomic_init(&do_time, 0L); }
-#endif
/* get the time (in units of itime) to the next timeout,
or -1 if there are no timeouts */
-static int next_time_internal(void) /* PRE: tiw_lock taken by caller */
+static erts_aint_t next_time_internal(void) /* PRE: tiw_lock taken by caller */
{
int i, tm, nto;
unsigned int min;
ErlTimer* p;
- long dt;
+ erts_aint_t dt;
if (tiw_nto == 0)
return -1; /* no timeouts in wheel */
+
+ if (tiw_min_ptr) {
+ min = tiw_min;
+ dt = do_time_read();
+ return ((min >= dt) ? (min - dt) : 0);
+ }
/* start going through wheel to find next timeout */
tm = nto = 0;
@@ -185,11 +142,17 @@ static int next_time_internal(void) /* PRE: tiw_lock taken by caller */
if (p->count == 0) {
/* found next timeout */
dt = do_time_read();
+ /* p->count is zero */
+ tiw_min_ptr = p;
+ tiw_min = tm;
return ((tm >= dt) ? (tm - dt) : 0);
} else {
/* keep shortest time in 'min' */
- if (tm + p->count*TIW_SIZE < min)
+ if (tm + p->count*TIW_SIZE < min) {
min = tm + p->count*TIW_SIZE;
+ tiw_min_ptr = p;
+ tiw_min = min;
+ }
}
p = p->next;
}
@@ -202,11 +165,35 @@ static int next_time_internal(void) /* PRE: tiw_lock taken by caller */
return ((min >= dt) ? (min - dt) : 0);
}
-#if !defined(ERTS_TIMER_THREAD)
+static void remove_timer(ErlTimer *p) {
+ /* first */
+ if (!p->prev) {
+ tiw[p->slot] = p->next;
+ if(p->next)
+ p->next->prev = NULL;
+ } else {
+ p->prev->next = p->next;
+ }
+
+ /* last */
+ if (!p->next) {
+ if (p->prev)
+ p->prev->next = NULL;
+ } else {
+ p->next->prev = p->prev;
+ }
+
+ p->next = NULL;
+ p->prev = NULL;
+ /* Make sure cancel callback isn't called */
+ p->active = 0;
+ tiw_nto--;
+}
+
/* Private export to erl_time_sup.c */
-int next_time(void)
+erts_aint_t erts_next_time(void)
{
- int ret;
+ erts_aint_t ret;
erts_smp_mtx_lock(&tiw_lock);
(void)do_time_update();
@@ -214,14 +201,13 @@ int next_time(void)
erts_smp_mtx_unlock(&tiw_lock);
return ret;
}
-#endif
-static ERTS_INLINE void bump_timer_internal(long dt) /* PRE: tiw_lock is write-locked */
+static ERTS_INLINE void bump_timer_internal(erts_aint_t dt) /* PRE: tiw_lock is write-locked */
{
Uint keep_pos;
Uint count;
ErlTimer *p, **prev, *timeout_head, **timeout_tail;
- Uint dtime = (unsigned long)dt;
+ Uint dtime = (Uint) dt;
/* no need to bump the position if there aren't any timeouts */
if (tiw_nto == 0) {
@@ -242,12 +228,16 @@ static ERTS_INLINE void bump_timer_internal(long dt) /* PRE: tiw_lock is write-l
if (tiw_pos == keep_pos) count--;
prev = &tiw[tiw_pos];
while ((p = *prev) != NULL) {
+ ASSERT( p != p->next);
if (p->count < count) { /* we have a timeout */
- *prev = p->next; /* Remove from list */
- tiw_nto--;
- p->next = NULL;
- p->active = 0; /* Make sure cancel callback
- isn't called */
+ /* remove min time */
+ if (tiw_min_ptr == p) {
+ tiw_min_ptr = NULL;
+ tiw_min = 0;
+ }
+
+ /* Remove from list */
+ remove_timer(p);
*timeout_tail = p; /* Insert in timeout queue */
timeout_tail = &p->next;
}
@@ -261,6 +251,8 @@ static ERTS_INLINE void bump_timer_internal(long dt) /* PRE: tiw_lock is write-l
dtime--;
}
tiw_pos = keep_pos;
+ if (tiw_min_ptr)
+ tiw_min -= dt;
erts_smp_mtx_unlock(&tiw_lock);
@@ -275,24 +267,17 @@ static ERTS_INLINE void bump_timer_internal(long dt) /* PRE: tiw_lock is write-l
* callback is called.
*/
p->next = NULL;
+ p->prev = NULL;
p->slot = 0;
(*p->timeout)(p->arg);
}
}
-#if defined(ERTS_TIMER_THREAD)
-static void timer_thread_bump_timer(void)
-{
- erts_smp_mtx_lock(&tiw_lock);
- bump_timer_internal(do_time_reset());
-}
-#else
-void bump_timer(long dt) /* dt is value from do_time */
+void erts_bump_timer(erts_aint_t dt) /* dt is value from do_time */
{
erts_smp_mtx_lock(&tiw_lock);
bump_timer_internal(dt);
}
-#endif
Uint
erts_timer_wheel_memory_size(void)
@@ -300,82 +285,10 @@ erts_timer_wheel_memory_size(void)
return (Uint) TIW_SIZE * sizeof(ErlTimer*);
}
-#if defined(ERTS_TIMER_THREAD)
-static struct erts_iwait *timer_thread_iwait;
-
-static int timer_thread_setup_delay(SysTimeval *rem_time)
-{
- long elapsed;
- int ticks;
-
- erts_smp_mtx_lock(&tiw_lock);
- elapsed = do_time_update();
- ticks = next_time_internal();
- if (ticks == -1) /* timer queue empty */
- ticks = 100*1000*1000;
- if (elapsed > ticks)
- elapsed = ticks;
- ticks -= elapsed;
- //ticks *= CLOCK_RESOLUTION;
- rem_time->tv_sec = ticks / 1000;
- rem_time->tv_usec = 1000 * (ticks % 1000);
- ticks_end = ticks;
- erts_smp_mtx_unlock(&tiw_lock);
- return ticks;
-}
-
-static void *timer_thread_start(void *ignore)
-{
- SysTimeval delay;
-
-#ifdef ERTS_ENABLE_LOCK_CHECK
- erts_lc_set_thread_name("timer");
-#endif
- erts_register_blockable_thread();
-
- for(;;) {
- if (timer_thread_setup_delay(&delay)) {
- erts_smp_activity_begin(ERTS_ACTIVITY_WAIT, NULL, NULL, NULL);
- ASSERT_NO_LOCKED_LOCKS;
- erts_iwait_wait(timer_thread_iwait, &delay);
- ASSERT_NO_LOCKED_LOCKS;
- erts_smp_activity_end(ERTS_ACTIVITY_WAIT, NULL, NULL, NULL);
- }
- else
- erts_smp_chk_system_block(NULL, NULL, NULL);
- timer_thread_bump_timer();
- ASSERT_NO_LOCKED_LOCKS;
- }
- /*NOTREACHED*/
- return NULL;
-}
-
-static ERTS_INLINE void timer_thread_post_insert(Uint ticks)
-{
- if ((Sint)ticks < ticks_end)
- erts_iwait_interrupt(timer_thread_iwait);
-}
-
-static void timer_thread_init(void)
-{
- erts_thr_opts_t opts = ERTS_THR_OPTS_DEFAULT_INITER;
- erts_tid_t tid;
-
- opts->detached = 1;
-
- timer_thread_iwait = erts_iwait_init();
- erts_thr_create(&tid, timer_thread_start, NULL, &opts);
-}
-
-#else
-static ERTS_INLINE void timer_thread_post_insert(Uint ticks) { }
-static ERTS_INLINE void timer_thread_init(void) { }
-#endif
-
/* this routine links the time cells into a free list at the start
and sets the time queue as empty */
void
-init_time(void)
+erts_init_time(void)
{
int i;
@@ -391,10 +304,13 @@ init_time(void)
tiw[i] = NULL;
do_time_init();
tiw_pos = tiw_nto = 0;
-
- timer_thread_init();
+ tiw_min_ptr = NULL;
+ tiw_min = 0;
}
+
+
+
/*
** Insert a process into the time queue, with a timeout 't'
*/
@@ -424,16 +340,31 @@ insert_timer(ErlTimer* p, Uint t)
/* insert at head of list at slot */
p->next = tiw[tm];
+ p->prev = NULL;
+ if (p->next != NULL)
+ p->next->prev = p;
tiw[tm] = p;
- tiw_nto++;
- timer_thread_post_insert(ticks);
+
+ /* insert min time */
+ if ((tiw_nto == 0) || ((tiw_min_ptr != NULL) && (ticks < tiw_min))) {
+ tiw_min = ticks;
+ tiw_min_ptr = p;
+ }
+ if ((tiw_min_ptr == p) && (ticks > tiw_min)) {
+ /* some other timer might be 'min' now */
+ tiw_min = 0;
+ tiw_min_ptr = NULL;
+ }
+
+ tiw_nto++;
}
void
-erl_set_timer(ErlTimer* p, ErlTimeoutProc timeout, ErlCancelProc cancel,
+erts_set_timer(ErlTimer* p, ErlTimeoutProc timeout, ErlCancelProc cancel,
void* arg, Uint t)
{
+
erts_deliver_time();
erts_smp_mtx_lock(&tiw_lock);
if (p->active) { /* XXX assert ? */
@@ -446,42 +377,34 @@ erl_set_timer(ErlTimer* p, ErlTimeoutProc timeout, ErlCancelProc cancel,
p->active = 1;
insert_timer(p, t);
erts_smp_mtx_unlock(&tiw_lock);
-#if defined(ERTS_SMP) && !defined(ERTS_TIMER_THREAD)
+#if defined(ERTS_SMP)
if (t <= (Uint) LONG_MAX)
erts_sys_schedule_interrupt_timed(1, (long) t);
#endif
}
void
-erl_cancel_timer(ErlTimer* p)
+erts_cancel_timer(ErlTimer* p)
{
- ErlTimer *tp;
- ErlTimer **prev;
-
erts_smp_mtx_lock(&tiw_lock);
if (!p->active) { /* allow repeated cancel (drivers) */
erts_smp_mtx_unlock(&tiw_lock);
return;
}
- /* find p in linked list at slot p->slot and remove it */
- prev = &tiw[p->slot];
- while ((tp = *prev) != NULL) {
- if (tp == p) {
- *prev = p->next; /* Remove from list */
- tiw_nto--;
- p->next = NULL;
- p->slot = p->count = 0;
- p->active = 0;
- if (p->cancel != NULL) {
- erts_smp_mtx_unlock(&tiw_lock);
- (*p->cancel)(p->arg);
- } else {
- erts_smp_mtx_unlock(&tiw_lock);
- }
- return;
- } else {
- prev = &tp->next;
- }
+
+ /* is it the 'min' timer, remove min */
+ if (p == tiw_min_ptr) {
+ tiw_min_ptr = NULL;
+ tiw_min = 0;
+ }
+
+ remove_timer(p);
+ p->slot = p->count = 0;
+
+ if (p->cancel != NULL) {
+ erts_smp_mtx_unlock(&tiw_lock);
+ (*p->cancel)(p->arg);
+ return;
}
erts_smp_mtx_unlock(&tiw_lock);
}
@@ -493,10 +416,10 @@ erl_cancel_timer(ErlTimer* p)
immediately if it hadn't been cancelled).
*/
Uint
-time_left(ErlTimer *p)
+erts_time_left(ErlTimer *p)
{
Uint left;
- long dt;
+ erts_aint_t dt;
erts_smp_mtx_lock(&tiw_lock);
@@ -517,12 +440,11 @@ time_left(ErlTimer *p)
erts_smp_mtx_unlock(&tiw_lock);
- return left * itime;
+ return (Uint) left * itime;
}
#ifdef DEBUG
-
-void p_slpq()
+void erts_p_slpq()
{
int i;
ErlTimer* p;
@@ -551,5 +473,4 @@ void p_slpq()
erts_smp_mtx_unlock(&tiw_lock);
}
-
#endif /* DEBUG */