diff options
Diffstat (limited to 'erts/emulator/beam/time.c')
| -rw-r--r-- | erts/emulator/beam/time.c | 847 |
1 files changed, 520 insertions, 327 deletions
diff --git a/erts/emulator/beam/time.c b/erts/emulator/beam/time.c index 2fd8e0cf00..988338ed81 100644 --- a/erts/emulator/beam/time.c +++ b/erts/emulator/beam/time.c @@ -3,16 +3,17 @@ * * Copyright Ericsson AB 1996-2013. 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 - * compliance with the License. You should have received a copy of the - * Erlang Public License along with this software. If not, it can be - * retrieved online at http://www.erlang.org/. - * - * Software distributed under the License is distributed on an "AS IS" - * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See - * the License for the specific language governing rights and limitations - * under the License. + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. * * %CopyrightEnd% */ @@ -76,6 +77,11 @@ #include "sys.h" #include "erl_vm.h" #include "global.h" +#define ERTS_WANT_TIMER_WHEEL_API +#include "erl_time.h" + +#define ERTS_MONOTONIC_DAY ERTS_SEC_TO_MONOTONIC(60*60*24) +#define ERTS_CLKTCKS_DAY ERTS_MONOTONIC_TO_CLKTCKS(ERTS_MONOTONIC_DAY) #ifdef ERTS_ENABLE_LOCK_CHECK #define ASSERT_NO_LOCKED_LOCKS erts_lc_check_exact(NULL, 0) @@ -83,26 +89,25 @@ #define ASSERT_NO_LOCKED_LOCKS #endif -static erts_smp_mtx_t tiw_lock; - - -/* BEGIN tiw_lock protected variables -** -** The individual timer cells in tiw are also protected by the same mutex. -*/ +#if 0 +# define ERTS_TW_DEBUG +#endif +#if defined(DEBUG) && !defined(ERTS_TW_DEBUG) +# define ERTS_TW_DEBUG +#endif -#ifdef SMALL_MEMORY -#define TIW_SIZE 8192 +#undef ERTS_TW_ASSERT +#if defined(ERTS_TW_DEBUG) +# define ERTS_TW_ASSERT(E) ERTS_ASSERT(E) #else -#define TIW_SIZE 65536 /* timing wheel size (should be a power of 2) */ +# define ERTS_TW_ASSERT(E) ((void) 1) #endif -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 */ +#ifdef ERTS_TW_DEBUG +# define ERTS_TWHEEL_BUMP_YIELD_LIMIT 5 +#else +# define ERTS_TWHEEL_BUMP_YIELD_LIMIT 100 +#endif /* Actual interval time chosen by sys_init_time() */ @@ -114,392 +119,580 @@ static int tiw_itime; /* Constant after init */ # define TIW_ITIME tiw_itime #endif -erts_smp_atomic32_t do_time; /* set at clock interrupt */ -static ERTS_INLINE erts_short_time_t do_time_read(void) -{ - return erts_smp_atomic32_read_acqb(&do_time); -} - -static ERTS_INLINE erts_short_time_t do_time_update(void) +struct ErtsTimerWheel_ { + ErtsTWheelTimer *w[ERTS_TIW_SIZE]; + ErtsMonotonicTime pos; + Uint nto; + struct { + ErtsTWheelTimer *head; + ErtsTWheelTimer *tail; + Uint nto; + } at_once; + int yield_slot; + int yield_slots_left; + int yield_start_pos; + ErtsTWheelTimer sentinel; + int true_next_timeout_time; + ErtsMonotonicTime next_timeout_time; +}; + +static ERTS_INLINE ErtsMonotonicTime +find_next_timeout(ErtsSchedulerData *esdp, + ErtsTimerWheel *tiw, + int search_all, + ErtsMonotonicTime curr_time, /* When !search_all */ + ErtsMonotonicTime max_search_time) /* When !search_all */ { - return do_time_read(); -} - -static ERTS_INLINE void do_time_init(void) -{ - erts_smp_atomic32_init_nob(&do_time, 0); -} + int start_ix, tiw_pos_ix; + ErtsTWheelTimer *p; + int true_min_timeout = 0; + ErtsMonotonicTime min_timeout, min_timeout_pos, slot_timeout_pos; + + if (tiw->nto == 0) { /* no timeouts in wheel */ + if (!search_all) + min_timeout_pos = tiw->pos; + else { + curr_time = erts_get_monotonic_time(esdp); + tiw->pos = min_timeout_pos = ERTS_MONOTONIC_TO_CLKTCKS(curr_time); + } + min_timeout_pos += ERTS_MONOTONIC_TO_CLKTCKS(ERTS_MONOTONIC_DAY); + goto found_next; + } -/* get the time (in units of TIW_ITIME) to the next timeout, - or -1 if there are no timeouts */ + slot_timeout_pos = min_timeout_pos = tiw->pos; + if (search_all) + min_timeout_pos += ERTS_MONOTONIC_TO_CLKTCKS(ERTS_MONOTONIC_DAY); + else + min_timeout_pos = ERTS_MONOTONIC_TO_CLKTCKS(curr_time + max_search_time); -static erts_short_time_t next_time_internal(void) /* PRE: tiw_lock taken by caller */ -{ - int i, tm, nto; - Uint32 min; - ErlTimer* p; - erts_short_time_t dt; - - if (tiw_nto == 0) - return -1; /* no timeouts in wheel */ + start_ix = tiw_pos_ix = (int) (tiw->pos & (ERTS_TIW_SIZE-1)); - 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; - min = (Uint32) -1; /* max Uint32 */ - i = tiw_pos; do { - p = tiw[i]; - while (p != NULL) { - nto++; - 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) { - min = tm + p->count*TIW_SIZE; - tiw_min_ptr = p; - tiw_min = min; + if (++slot_timeout_pos >= min_timeout_pos) + break; + + p = tiw->w[tiw_pos_ix]; + + if (p) { + ErtsTWheelTimer *end = p; + + do { + ErtsMonotonicTime timeout_pos; + timeout_pos = p->timeout_pos; + if (min_timeout_pos > timeout_pos) { + true_min_timeout = 1; + min_timeout_pos = timeout_pos; + if (min_timeout_pos <= slot_timeout_pos) + goto found_next; } - } - p = p->next; + p = p->next; + } while (p != end); } - /* when we have found all timeouts the shortest time will be in min */ - if (nto == tiw_nto) break; - tm++; - i = (i + 1) % TIW_SIZE; - } while (i != tiw_pos); - dt = do_time_read(); - if (min <= (Uint32) dt) - return 0; - if ((min - (Uint32) dt) > (Uint32) ERTS_SHORT_TIME_T_MAX) - return ERTS_SHORT_TIME_T_MAX; - return (erts_short_time_t) (min - (Uint32) dt); + + tiw_pos_ix++; + if (tiw_pos_ix == ERTS_TIW_SIZE) + tiw_pos_ix = 0; + } while (start_ix != tiw_pos_ix); + +found_next: + + min_timeout = ERTS_CLKTCKS_TO_MONOTONIC(min_timeout_pos); + tiw->next_timeout_time = min_timeout; + tiw->true_next_timeout_time = true_min_timeout; + + return min_timeout; } -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; +static ERTS_INLINE void +insert_timer_into_slot(ErtsTimerWheel *tiw, int slot, ErtsTWheelTimer *p) +{ + ERTS_TW_ASSERT(slot >= 0); + ERTS_TW_ASSERT(slot < ERTS_TIW_SIZE); + p->slot = slot; + if (!tiw->w[slot]) { + tiw->w[slot] = p; + p->next = p; + p->prev = p; + } + else { + ErtsTWheelTimer *next, *prev; + next = tiw->w[slot]; + prev = next->prev; + p->next = next; + p->prev = prev; + prev->next = p; + next->prev = p; } +} - /* last */ - if (!p->next) { +static ERTS_INLINE void +remove_timer(ErtsTimerWheel *tiw, ErtsTWheelTimer *p) +{ + int slot = p->slot; + ERTS_TW_ASSERT(slot != ERTS_TWHEEL_SLOT_INACTIVE); + + if (slot >= 0) { + /* + * Timer in wheel or in circular + * list of timers currently beeing + * triggered (referred by sentinel). + */ + ERTS_TW_ASSERT(slot < ERTS_TIW_SIZE); + + if (p->next == p) { + ERTS_TW_ASSERT(tiw->w[slot] == p); + tiw->w[slot] = NULL; + } + else { + if (tiw->w[slot] == p) + tiw->w[slot] = p->next; + p->prev->next = p->next; + p->next->prev = p->prev; + } + } + else { + /* Timer in "at once" queue... */ + ERTS_TW_ASSERT(slot == ERTS_TWHEEL_SLOT_AT_ONCE); if (p->prev) - p->prev->next = NULL; - } else { - p->next->prev = p->prev; + p->prev->next = p->next; + else { + ERTS_TW_ASSERT(tiw->at_once.head == p); + tiw->at_once.head = p->next; + } + if (p->next) + p->next->prev = p->prev; + else { + ERTS_TW_ASSERT(tiw->at_once.tail == p); + tiw->at_once.tail = p->prev; + } + ERTS_TW_ASSERT(tiw->at_once.nto > 0); + tiw->at_once.nto--; } - p->next = NULL; - p->prev = NULL; - /* Make sure cancel callback isn't called */ - p->active = 0; - tiw_nto--; + p->slot = ERTS_TWHEEL_SLOT_INACTIVE; + + tiw->nto--; } -/* Private export to erl_time_sup.c */ -erts_short_time_t erts_next_time(void) +ErtsMonotonicTime +erts_check_next_timeout_time(ErtsSchedulerData *esdp) { - erts_short_time_t ret; + ErtsTimerWheel *tiw = esdp->timer_wheel; + if (tiw->true_next_timeout_time) + return tiw->next_timeout_time; + return find_next_timeout(esdp, tiw, 1, 0, 0); +} + +#ifndef ERTS_TW_DEBUG +#define ERTS_DBG_CHK_SAFE_TO_SKIP_TO(TIW, TO) ((void) 0) +#else +#define ERTS_DBG_CHK_SAFE_TO_SKIP_TO(TIW, TO) debug_check_safe_to_skip_to((TIW), (TO)) +static void +debug_check_safe_to_skip_to(ErtsTimerWheel *tiw, ErtsMonotonicTime skip_to_pos) +{ + int slots, ix; + ErtsTWheelTimer *tmr; + ErtsMonotonicTime tmp; + + ix = (int) (tiw->pos & (ERTS_TIW_SIZE-1)); + tmp = skip_to_pos - tiw->pos; + ERTS_TW_ASSERT(tmp >= 0); + if (tmp < (ErtsMonotonicTime) ERTS_TIW_SIZE) + slots = (int) tmp; + else + slots = ERTS_TIW_SIZE; + + while (slots > 0) { + tmr = tiw->w[ix]; + if (tmr) { + ErtsTWheelTimer *end = tmr; + do { + ERTS_TW_ASSERT(tmr->timeout_pos > skip_to_pos); + tmr = tmr->next; + } while (tmr != end); + } + ix++; + if (ix == ERTS_TIW_SIZE) + ix = 0; + slots--; + } +} +#endif - erts_smp_mtx_lock(&tiw_lock); - (void)do_time_update(); - ret = next_time_internal(); - erts_smp_mtx_unlock(&tiw_lock); - return ret; +static ERTS_INLINE void +timeout_timer(ErtsTWheelTimer *p) +{ + ErlTimeoutProc timeout; + void *arg; + p->slot = ERTS_TWHEEL_SLOT_INACTIVE; + timeout = p->u.func.timeout; + arg = p->u.func.arg; + (*timeout)(arg); + ASSERT_NO_LOCKED_LOCKS; } -static ERTS_INLINE void bump_timer_internal(erts_short_time_t dt) /* PRE: tiw_lock is write-locked */ +void +erts_bump_timers(ErtsTimerWheel *tiw, ErtsMonotonicTime curr_time) { - Uint keep_pos; - Uint count; - ErlTimer *p, **prev, *timeout_head, **timeout_tail; - Uint dtime = (Uint) dt; - - /* no need to bump the position if there aren't any timeouts */ - if (tiw_nto == 0) { - erts_smp_mtx_unlock(&tiw_lock); - return; + int tiw_pos_ix, slots, yielded_slot_restarted, yield_count; + ErtsMonotonicTime bump_to, tmp_slots, old_pos; + + yield_count = ERTS_TWHEEL_BUMP_YIELD_LIMIT; + + /* + * In order to be fair we always continue with work + * where we left off when restarting after a yield. + */ + + if (tiw->yield_slot >= 0) { + yielded_slot_restarted = 1; + tiw_pos_ix = tiw->yield_slot; + slots = tiw->yield_slots_left; + bump_to = tiw->pos; + old_pos = tiw->yield_start_pos; + goto restart_yielded_slot; } - /* if do_time > TIW_SIZE we want to go around just once */ - count = (Uint)(dtime / TIW_SIZE) + 1; - keep_pos = (tiw_pos + dtime) % TIW_SIZE; - if (dtime > TIW_SIZE) dtime = TIW_SIZE; - - timeout_head = NULL; - timeout_tail = &timeout_head; - while (dtime > 0) { - /* this is to decrease the counters with the right amount */ - /* when dtime >= TIW_SIZE */ - 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 */ - /* remove min time */ - if (tiw_min_ptr == p) { - tiw_min_ptr = NULL; - tiw_min = 0; + do { + + yielded_slot_restarted = 0; + + bump_to = ERTS_MONOTONIC_TO_CLKTCKS(curr_time); + + while (1) { + ErtsTWheelTimer *p; + + old_pos = tiw->pos; + + if (tiw->nto == 0) { + empty_wheel: + ERTS_DBG_CHK_SAFE_TO_SKIP_TO(tiw, bump_to); + tiw->true_next_timeout_time = 0; + tiw->next_timeout_time = curr_time + ERTS_MONOTONIC_DAY; + tiw->pos = bump_to; + tiw->yield_slot = ERTS_TWHEEL_SLOT_INACTIVE; + return; + } + + p = tiw->at_once.head; + while (p) { + if (--yield_count <= 0) { + ERTS_TW_ASSERT(tiw->nto > 0); + ERTS_TW_ASSERT(tiw->at_once.nto > 0); + tiw->yield_slot = ERTS_TWHEEL_SLOT_AT_ONCE; + tiw->true_next_timeout_time = 1; + tiw->next_timeout_time = ERTS_CLKTCKS_TO_MONOTONIC(old_pos); + return; } - /* Remove from list */ - remove_timer(p); - *timeout_tail = p; /* Insert in timeout queue */ - timeout_tail = &p->next; + ERTS_TW_ASSERT(tiw->nto > 0); + ERTS_TW_ASSERT(tiw->at_once.nto > 0); + tiw->nto--; + tiw->at_once.nto--; + tiw->at_once.head = p->next; + if (p->next) + p->next->prev = NULL; + else + tiw->at_once.tail = NULL; + + timeout_timer(p); + + p = tiw->at_once.head; } - else { - /* no timeout, just decrease counter */ - p->count -= count; - prev = &p->next; + + if (tiw->pos >= bump_to) + break; + + if (tiw->nto == 0) + goto empty_wheel; + + if (tiw->true_next_timeout_time) { + ErtsMonotonicTime skip_until_pos; + /* + * No need inspecting slots where we know no timeouts + * to trigger should reside. + */ + + skip_until_pos = ERTS_MONOTONIC_TO_CLKTCKS(tiw->next_timeout_time); + if (skip_until_pos > bump_to) + skip_until_pos = bump_to; + + skip_until_pos--; + + if (skip_until_pos > tiw->pos) { + ERTS_DBG_CHK_SAFE_TO_SKIP_TO(tiw, skip_until_pos); + + tiw->pos = skip_until_pos; + } + } + + tiw_pos_ix = (int) ((tiw->pos+1) & (ERTS_TIW_SIZE-1)); + tmp_slots = (bump_to - tiw->pos); + if (tmp_slots < (ErtsMonotonicTime) ERTS_TIW_SIZE) + slots = (int) tmp_slots; + else + slots = ERTS_TIW_SIZE; + + tiw->pos = bump_to; + + while (slots > 0) { + + p = tiw->w[tiw_pos_ix]; + if (p) { + if (p->next == p) { + ERTS_TW_ASSERT(tiw->sentinel.next == &tiw->sentinel); + ERTS_TW_ASSERT(tiw->sentinel.prev == &tiw->sentinel); + } + else { + tiw->sentinel.next = p->next; + tiw->sentinel.prev = p->prev; + tiw->sentinel.next->prev = &tiw->sentinel; + tiw->sentinel.prev->next = &tiw->sentinel; + } + tiw->w[tiw_pos_ix] = NULL; + + while (1) { + + if (p->timeout_pos > bump_to) { + /* Very unusual case... */ + ++yield_count; + insert_timer_into_slot(tiw, tiw_pos_ix, p); + } + else { + /* Normal case... */ + timeout_timer(p); + tiw->nto--; + } + + restart_yielded_slot: + + p = tiw->sentinel.next; + if (p == &tiw->sentinel) { + ERTS_TW_ASSERT(tiw->sentinel.prev == &tiw->sentinel); + break; + } + + if (--yield_count <= 0) { + tiw->true_next_timeout_time = 1; + tiw->next_timeout_time = ERTS_CLKTCKS_TO_MONOTONIC(old_pos); + tiw->yield_slot = tiw_pos_ix; + tiw->yield_slots_left = slots; + tiw->yield_start_pos = old_pos; + return; /* Yield! */ + } + + tiw->sentinel.next = p->next; + p->next->prev = &tiw->sentinel; + } + } + tiw_pos_ix++; + if (tiw_pos_ix == ERTS_TIW_SIZE) + tiw_pos_ix = 0; + slots--; } } - tiw_pos = (tiw_pos + 1) % TIW_SIZE; - dtime--; - } - tiw_pos = keep_pos; - if (tiw_min_ptr) - tiw_min -= dt; - - erts_smp_mtx_unlock(&tiw_lock); - - /* Call timedout timers callbacks */ - while (timeout_head) { - p = timeout_head; - timeout_head = p->next; - /* Here comes hairy use of the timer fields! - * They are reset without having the lock. - * It is assumed that no code but this will - * accesses any field until the ->timeout - * callback is called. - */ - p->next = NULL; - p->prev = NULL; - p->slot = 0; - (*p->timeout)(p->arg); - } -} -void erts_bump_timer(erts_short_time_t dt) /* dt is value from do_time */ -{ - erts_smp_mtx_lock(&tiw_lock); - bump_timer_internal(dt); + } while (yielded_slot_restarted); + + tiw->yield_slot = ERTS_TWHEEL_SLOT_INACTIVE; + tiw->true_next_timeout_time = 0; + tiw->next_timeout_time = curr_time + ERTS_MONOTONIC_DAY; + + /* Search at most two seconds ahead... */ + (void) find_next_timeout(NULL, tiw, 0, curr_time, ERTS_SEC_TO_MONOTONIC(2)); } Uint erts_timer_wheel_memory_size(void) { - return (Uint) TIW_SIZE * sizeof(ErlTimer*); + return sizeof(ErtsTimerWheel)*erts_no_schedulers; +} + +ErtsTimerWheel * +erts_create_timer_wheel(ErtsSchedulerData *esdp) +{ + ErtsMonotonicTime mtime; + int i; + ErtsTimerWheel *tiw; + tiw = erts_alloc_permanent_cache_aligned(ERTS_ALC_T_TIMER_WHEEL, + sizeof(ErtsTimerWheel)); + for(i = 0; i < ERTS_TIW_SIZE; i++) + tiw->w[i] = NULL; + + mtime = erts_get_monotonic_time(esdp); + tiw->pos = ERTS_MONOTONIC_TO_CLKTCKS(mtime); + tiw->nto = 0; + tiw->at_once.head = NULL; + tiw->at_once.tail = NULL; + tiw->at_once.nto = 0; + tiw->yield_slot = ERTS_TWHEEL_SLOT_INACTIVE; + tiw->true_next_timeout_time = 0; + tiw->next_timeout_time = mtime + ERTS_MONOTONIC_DAY; + tiw->sentinel.next = &tiw->sentinel; + tiw->sentinel.prev = &tiw->sentinel; + tiw->sentinel.u.func.timeout = NULL; + tiw->sentinel.u.func.cancel = NULL; + tiw->sentinel.u.func.arg = NULL; + return tiw; +} + +ErtsNextTimeoutRef +erts_get_next_timeout_reference(ErtsTimerWheel *tiw) +{ + return (ErtsNextTimeoutRef) &tiw->next_timeout_time; } + /* this routine links the time cells into a free list at the start and sets the time queue as empty */ void -erts_init_time(void) +erts_init_time(int time_correction, ErtsTimeWarpMode time_warp_mode) { - int i, itime; + int itime; /* system dependent init; must be done before do_time_init() if timer thread is enabled */ - itime = erts_init_time_sup(); + itime = erts_init_time_sup(time_correction, time_warp_mode); #ifdef TIW_ITIME_IS_CONSTANT if (itime != TIW_ITIME) { - erl_exit(ERTS_ABORT_EXIT, "timer resolution mismatch %d != %d", itime, TIW_ITIME); + erts_exit(ERTS_ABORT_EXIT, "timer resolution mismatch %d != %d", itime, TIW_ITIME); } #else tiw_itime = itime; #endif +} - erts_smp_mtx_init(&tiw_lock, "timer_wheel"); +void +erts_twheel_set_timer(ErtsTimerWheel *tiw, + ErtsTWheelTimer *p, ErlTimeoutProc timeout, + ErlCancelProc cancel, void *arg, + ErtsMonotonicTime timeout_pos) +{ + ErtsMonotonicTime timeout_time; - tiw = (ErlTimer**) erts_alloc(ERTS_ALC_T_TIMER_WHEEL, - TIW_SIZE * sizeof(ErlTimer*)); - for(i = 0; i < TIW_SIZE; i++) - tiw[i] = NULL; - do_time_init(); - tiw_pos = tiw_nto = 0; - tiw_min_ptr = NULL; - tiw_min = 0; -} + p->u.func.timeout = timeout; + p->u.func.cancel = cancel; + p->u.func.arg = arg; + ERTS_TW_ASSERT(p->slot == ERTS_TWHEEL_SLOT_INACTIVE); + if (timeout_pos <= tiw->pos) { + tiw->nto++; + tiw->at_once.nto++; + p->next = NULL; + p->prev = tiw->at_once.tail; + if (tiw->at_once.tail) { + ERTS_TW_ASSERT(tiw->at_once.head); + tiw->at_once.tail->next = p; + } + else { + ERTS_TW_ASSERT(!tiw->at_once.head); + tiw->at_once.head = p; + } + tiw->at_once.tail = p; + p->timeout_pos = tiw->pos; + p->slot = ERTS_TWHEEL_SLOT_AT_ONCE; + timeout_time = ERTS_CLKTCKS_TO_MONOTONIC(tiw->pos); + } + else { + int slot; + /* calculate slot */ + slot = (int) (timeout_pos & (ERTS_TIW_SIZE-1)); -/* -** Insert a process into the time queue, with a timeout 't' -*/ -static void -insert_timer(ErlTimer* p, Uint t) -{ - Uint tm; - Uint64 ticks; + insert_timer_into_slot(tiw, slot, p); - /* The current slot (tiw_pos) in timing wheel is the next slot to be - * be processed. Hence no extra time tick is needed. - * - * (x + y - 1)/y is precisely the "number of bins" formula. - */ - ticks = (t + (TIW_ITIME - 1)) / TIW_ITIME; + tiw->nto++; - /* - * Ticks must be a Uint64, or the addition may overflow here, - * resulting in an incorrect value for p->count below. - */ - ticks += do_time_update(); /* Add backlog of unprocessed time */ - - /* calculate slot */ - tm = (ticks + tiw_pos) % TIW_SIZE; - p->slot = (Uint) tm; - p->count = (Uint) (ticks / TIW_SIZE); - - /* 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; - - - /* 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; + timeout_time = ERTS_CLKTCKS_TO_MONOTONIC(timeout_pos); + p->timeout_pos = timeout_pos; } - tiw_nto++; + if (timeout_time < tiw->next_timeout_time) { + tiw->true_next_timeout_time = 1; + tiw->next_timeout_time = timeout_time; + } } void -erts_set_timer(ErlTimer* p, ErlTimeoutProc timeout, ErlCancelProc cancel, - void* arg, Uint t) +erts_twheel_cancel_timer(ErtsTimerWheel *tiw, ErtsTWheelTimer *p) { - - erts_deliver_time(); - erts_smp_mtx_lock(&tiw_lock); - if (p->active) { /* XXX assert ? */ - erts_smp_mtx_unlock(&tiw_lock); - return; + if (p->slot != ERTS_TWHEEL_SLOT_INACTIVE) { + ErlCancelProc cancel; + void *arg; + remove_timer(tiw, p); + cancel = p->u.func.cancel; + arg = p->u.func.arg; + if (cancel) + (*cancel)(arg); } - p->timeout = timeout; - p->cancel = cancel; - p->arg = arg; - p->active = 1; - insert_timer(p, t); - erts_smp_mtx_unlock(&tiw_lock); -#if defined(ERTS_SMP) - if (t <= (Uint) ERTS_SHORT_TIME_T_MAX) - erts_sys_schedule_interrupt_timed(1, (erts_short_time_t) t); -#endif } void -erts_cancel_timer(ErlTimer* p) +erts_twheel_debug_foreach(ErtsTimerWheel *tiw, + void (*tclbk)(void *), + void (*func)(void *, + ErtsMonotonicTime, + void *), + void *arg) { - erts_smp_mtx_lock(&tiw_lock); - if (!p->active) { /* allow repeated cancel (drivers) */ - erts_smp_mtx_unlock(&tiw_lock); - return; - } - - /* is it the 'min' timer, remove min */ - if (p == tiw_min_ptr) { - tiw_min_ptr = NULL; - tiw_min = 0; + ErtsTWheelTimer *tmr; + int ix; + + tmr = tiw->sentinel.next; + while (tmr != &tiw->sentinel) { + if (tmr->u.func.timeout == tclbk) + (*func)(arg, tmr->timeout_pos, tmr->u.func.arg); + tmr = tmr->next; } - remove_timer(p); - p->slot = p->count = 0; - - if (p->cancel != NULL) { - erts_smp_mtx_unlock(&tiw_lock); - (*p->cancel)(p->arg); - return; + for (tmr = tiw->at_once.head; tmr; tmr = tmr->next) { + if (tmr->u.func.timeout == tclbk) + (*func)(arg, tmr->timeout_pos, tmr->u.func.arg); } - erts_smp_mtx_unlock(&tiw_lock); -} - -/* - Returns the amount of time left in ms until the timer 'p' is triggered. - 0 is returned if 'p' isn't active. - 0 is returned also if the timer is overdue (i.e., would have triggered - immediately if it hadn't been cancelled). -*/ -Uint -erts_time_left(ErlTimer *p) -{ - Uint left; - erts_short_time_t dt; - erts_smp_mtx_lock(&tiw_lock); - - if (!p->active) { - erts_smp_mtx_unlock(&tiw_lock); - return 0; + for (ix = 0; ix < ERTS_TIW_SIZE; ix++) { + tmr = tiw->w[ix]; + if (tmr) { + do { + if (tmr->u.func.timeout == tclbk) + (*func)(arg, tmr->timeout_pos, tmr->u.func.arg); + tmr = tmr->next; + } while (tmr != tiw->w[ix]); + } } - - if (p->slot < tiw_pos) - left = (p->count + 1) * TIW_SIZE + p->slot - tiw_pos; - else - left = p->count * TIW_SIZE + p->slot - tiw_pos; - dt = do_time_read(); - if (left < dt) - left = 0; - else - left -= dt; - - erts_smp_mtx_unlock(&tiw_lock); - - return (Uint) left * TIW_ITIME; } -#ifdef DEBUG +#ifdef ERTS_TW_DEBUG void erts_p_slpq(void) { + erts_printf("Not yet implemented...\n"); +#if 0 + ErtsMonotonicTime current_time = erts_get_monotonic_time(NULL); int i; - ErlTimer* p; + ErtsTWheelTimer* p; - erts_smp_mtx_lock(&tiw_lock); - /* print the whole wheel, starting at the current position */ - erts_printf("\ntiw_pos = %d tiw_nto %d\n", tiw_pos, tiw_nto); - i = tiw_pos; - if (tiw[i] != NULL) { + erts_printf("\ncurrent time = %bps tiw_pos = %d tiw_nto %d\n", + current_time, tiw->pos, tiw->nto); + i = tiw->pos; + if (tiw->w[i] != NULL) { erts_printf("%d:\n", i); - for(p = tiw[i]; p != NULL; p = p->next) { - erts_printf(" (count %d, slot %d)\n", - p->count, p->slot); + for(p = tiw->w[i]; p != NULL; p = p->next) { + erts_printf(" (timeout time %bps, slot %d)\n", + ERTS_CLKTCKS_TO_MONOTONIC(p->timeout_pos), + p->slot); } } - for(i = (i+1)%TIW_SIZE; i != tiw_pos; i = (i+1)%TIW_SIZE) { - if (tiw[i] != NULL) { + for(i = ((i+1) & (ERTS_TIW_SIZE-1)); i != (tiw->pos & (ERTS_TIW_SIZE-1)); i = ((i+1) & (ERTS_TIW_SIZE-1))) { + if (tiw->w[i] != NULL) { erts_printf("%d:\n", i); - for(p = tiw[i]; p != NULL; p = p->next) { - erts_printf(" (count %d, slot %d)\n", - p->count, p->slot); + for(p = tiw->w[i]; p != NULL; p = p->next) { + erts_printf(" (timeout time %bps, slot %d)\n", + ERTS_CLKTCKS_TO_MONOTONIC(p->timeout_pos), p->slot); } } } - - erts_smp_mtx_unlock(&tiw_lock); +#endif } -#endif /* DEBUG */ +#endif /* ERTS_TW_DEBUG */ |