2 * Copyright (c) 2016 Cisco and/or its affiliates.
3 * Licensed under the Apache License, Version 2.0 (the "License");
4 * you may not use this file except in compliance with the License.
5 * You may obtain a copy of the License at:
7 * http://www.apache.org/licenses/LICENSE-2.0
9 * Unless required by applicable law or agreed to in writing, software
10 * distributed under the License is distributed on an "AS IS" BASIS,
11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 * See the License for the specific language governing permissions and
13 * limitations under the License.
17 * @brief TW timer implementation TEMPLATE ONLY, do not compile directly
21 #if TW_START_STOP_TRACE_SIZE > 0
23 void TW (tw_timer_trace) (TWT (tw_timer_wheel) * tw, u32 timer_id,
24 u32 pool_index, u32 handle)
26 TWT (trace) * t = &tw->traces[tw->trace_index];
28 t->timer_id = timer_id;
29 t->pool_index = pool_index;
33 if (tw->trace_index == TW_START_STOP_TRACE_SIZE)
40 void TW (tw_search_trace) (TWT (tw_timer_wheel) * tw, u32 handle)
46 /* reverse search for the supplied handle */
48 start_pos = tw->trace_index;
50 start_pos = TW_START_STOP_TRACE_SIZE - 1;
54 for (i = start_pos; i > 0; i--)
57 if (t->handle == handle)
71 fformat (stderr, "handle 0x%x (%d) %s at trace %d\n",
72 handle, handle, s, i);
75 if (tw->trace_wrapped > 0)
77 for (i = TW_START_STOP_TRACE_SIZE; i >= tw->trace_index; i--)
80 if (t->handle == handle)
94 fformat (stderr, "handle 0x%x (%d) %s at trace %d\n",
95 handle, handle, s, i);
100 #endif /* TW_START_STOP_TRACE_SIZE > 0 */
103 TW (make_internal_timer_handle) (u32 pool_index, u32 timer_id)
107 ASSERT (timer_id < TW_TIMERS_PER_OBJECT);
108 #if LOG2_TW_TIMERS_PER_OBJECT > 0
109 ASSERT (pool_index < (1 << (32 - LOG2_TW_TIMERS_PER_OBJECT)));
111 handle = (timer_id << (32 - LOG2_TW_TIMERS_PER_OBJECT)) | (pool_index);
119 timer_addhead (TWT (tw_timer) * pool, u32 head_index, u32 new_index)
121 TWT (tw_timer) * head = pool_elt_at_index (pool, head_index);
122 TWT (tw_timer) * old_first;
124 TWT (tw_timer) * new;
126 new = pool_elt_at_index (pool, new_index);
128 if (PREDICT_FALSE (head->next == head_index))
130 head->next = head->prev = new_index;
131 new->next = new->prev = head_index;
135 old_first_index = head->next;
136 old_first = pool_elt_at_index (pool, old_first_index);
138 new->next = old_first_index;
139 new->prev = old_first->prev;
140 old_first->prev = new_index;
141 head->next = new_index;
145 timer_remove (TWT (tw_timer) * pool, TWT (tw_timer) * elt)
147 TWT (tw_timer) * next_elt, *prev_elt;
149 ASSERT (elt->user_handle != ~0);
151 next_elt = pool_elt_at_index (pool, elt->next);
152 prev_elt = pool_elt_at_index (pool, elt->prev);
154 next_elt->prev = elt->prev;
155 prev_elt->next = elt->next;
157 elt->prev = elt->next = ~0;
161 timer_add (TWT (tw_timer_wheel) * tw, TWT (tw_timer) * t, u64 interval)
163 #if TW_TIMER_WHEELS > 1
164 u16 slow_ring_offset;
167 #if TW_TIMER_WHEELS > 2
168 u16 glacier_ring_offset;
170 #if TW_OVERFLOW_VECTOR > 0
171 u64 interval_plus_time_to_wrap, triple_wrap_mask;
173 u16 fast_ring_offset;
174 tw_timer_wheel_slot_t *ts;
176 /* Factor interval into 1..3 wheel offsets */
177 #if TW_TIMER_WHEELS > 2
178 #if TW_OVERFLOW_VECTOR > 0
180 * This is tricky. Put a timer onto the overflow
181 * vector if the interval PLUS the time
182 * until the next triple-wrap exceeds one full revolution
183 * of all three wheels.
185 triple_wrap_mask = (1 << (3 * TW_RING_SHIFT)) - 1;
186 interval_plus_time_to_wrap =
187 interval + (tw->current_tick & triple_wrap_mask);
188 if ((interval_plus_time_to_wrap >= 1 << (3 * TW_RING_SHIFT)))
190 t->expiration_time = tw->current_tick + interval;
192 timer_addhead (tw->timers, ts->head_index, t - tw->timers);
193 #if TW_START_STOP_TRACE_SIZE > 0
194 TW (tw_timer_trace) (tw, timer_id, user_id, t - tw->timers);
200 glacier_ring_offset = interval >> (2 * TW_RING_SHIFT);
201 ASSERT ((u64) glacier_ring_offset < TW_SLOTS_PER_RING);
202 interval -= (((u64) glacier_ring_offset) << (2 * TW_RING_SHIFT));
204 #if TW_TIMER_WHEELS > 1
205 slow_ring_offset = interval >> TW_RING_SHIFT;
206 ASSERT ((u64) slow_ring_offset < TW_SLOTS_PER_RING);
207 interval -= (((u64) slow_ring_offset) << TW_RING_SHIFT);
209 fast_ring_offset = interval & TW_RING_MASK;
212 * Account for the current wheel positions(s)
213 * This is made slightly complicated by the fact that the current
214 * index vector will contain (TW_SLOTS_PER_RING, ...) when
215 * the actual position is (0, ...)
218 fast_ring_offset += tw->current_index[TW_TIMER_RING_FAST] & TW_RING_MASK;
220 #if TW_TIMER_WHEELS > 1
221 carry = fast_ring_offset >= TW_SLOTS_PER_RING ? 1 : 0;
222 fast_ring_offset %= TW_SLOTS_PER_RING;
223 slow_ring_offset += (tw->current_index[TW_TIMER_RING_SLOW] & TW_RING_MASK)
225 carry = slow_ring_offset >= TW_SLOTS_PER_RING ? 1 : 0;
226 slow_ring_offset %= TW_SLOTS_PER_RING;
229 #if TW_TIMER_WHEELS > 2
230 glacier_ring_offset +=
231 (tw->current_index[TW_TIMER_RING_GLACIER] & TW_RING_MASK) + carry;
232 glacier_ring_offset %= TW_SLOTS_PER_RING;
235 #if TW_TIMER_WHEELS > 2
236 if (glacier_ring_offset !=
237 (tw->current_index[TW_TIMER_RING_GLACIER] & TW_RING_MASK))
239 /* We'll need slow and fast ring offsets later */
240 t->slow_ring_offset = slow_ring_offset;
241 t->fast_ring_offset = fast_ring_offset;
243 ts = &tw->w[TW_TIMER_RING_GLACIER][glacier_ring_offset];
245 timer_addhead (tw->timers, ts->head_index, t - tw->timers);
246 #if TW_START_STOP_TRACE_SIZE > 0
247 TW (tw_timer_trace) (tw, timer_id, user_id, t - tw->timers);
253 #if TW_TIMER_WHEELS > 1
254 /* Timer expires more than 51.2 seconds from now? */
255 if (slow_ring_offset !=
256 (tw->current_index[TW_TIMER_RING_SLOW] & TW_RING_MASK))
258 /* We'll need the fast ring offset later... */
259 t->fast_ring_offset = fast_ring_offset;
261 ts = &tw->w[TW_TIMER_RING_SLOW][slow_ring_offset];
263 timer_addhead (tw->timers, ts->head_index, t - tw->timers);
264 #if TW_START_STOP_TRACE_SIZE > 0
265 TW (tw_timer_trace) (tw, timer_id, user_id, t - tw->timers);
270 fast_ring_offset %= TW_SLOTS_PER_RING;
273 /* Timer expires less than one fast-ring revolution from now */
274 ts = &tw->w[TW_TIMER_RING_FAST][fast_ring_offset];
276 timer_addhead (tw->timers, ts->head_index, t - tw->timers);
278 #if TW_FAST_WHEEL_BITMAP
279 tw->fast_slot_bitmap = clib_bitmap_set (tw->fast_slot_bitmap,
280 fast_ring_offset, 1);
282 #if TW_START_STOP_TRACE_SIZE > 0
283 TW (tw_timer_trace) (tw, timer_id, user_id, t - tw->timers);
288 * @brief Start a Tw Timer
289 * @param tw_timer_wheel_t * tw timer wheel object pointer
290 * @param u32 user_id user defined timer id, presumably for a tw session
291 * @param u32 timer_id app-specific timer ID. 4 bits.
292 * @param u64 interval timer interval in ticks
293 * @returns handle needed to cancel the timer
296 TW (tw_timer_start) (TWT (tw_timer_wheel) * tw, u32 user_id, u32 timer_id,
303 pool_get (tw->timers, t);
304 clib_memset (t, 0xff, sizeof (*t));
306 t->user_handle = TW (make_internal_timer_handle) (user_id, timer_id);
308 timer_add (tw, t, interval);
309 return t - tw->timers;
312 #if TW_TIMER_SCAN_FOR_HANDLE > 0
313 int TW (scan_for_handle) (TWT (tw_timer_wheel) * tw, u32 handle)
316 tw_timer_wheel_slot_t *ts;
317 TWT (tw_timer) * t, *head;
321 for (i = 0; i < TW_TIMER_WHEELS; i++)
323 for (j = 0; j < TW_SLOTS_PER_RING; j++)
326 head = pool_elt_at_index (tw->timers, ts->head_index);
327 next_index = head->next;
329 while (next_index != ts->head_index)
331 t = pool_elt_at_index (tw->timers, next_index);
332 if (next_index == handle)
334 clib_warning ("handle %d found in ring %d slot %d",
336 clib_warning ("user handle 0x%x", t->user_handle);
339 next_index = t->next;
345 #endif /* TW_TIMER_SCAN_FOR_HANDLE */
348 * @brief Stop a tw timer
349 * @param tw_timer_wheel_t * tw timer wheel object pointer
350 * @param u32 handle timer cancellation returned by tw_timer_start
352 void TW (tw_timer_stop) (TWT (tw_timer_wheel) * tw, u32 handle)
356 #if TW_TIMER_ALLOW_DUPLICATE_STOP
358 * A vlib process may have its timer expire, and receive
359 * an event before the expiration is processed.
360 * That results in a duplicate tw_timer_stop.
362 if (pool_is_free_index (tw->timers, handle))
365 #if TW_START_STOP_TRACE_SIZE > 0
366 TW (tw_timer_trace) (tw, ~0, ~0, handle);
369 t = pool_elt_at_index (tw->timers, handle);
371 /* in case of idiotic handle (e.g. passing a listhead index) */
372 ASSERT (t->user_handle != ~0);
374 timer_remove (tw->timers, t);
376 pool_put_index (tw->timers, handle);
379 int TW (tw_timer_handle_is_free) (TWT (tw_timer_wheel) * tw, u32 handle)
381 return pool_is_free_index (tw->timers, handle);
385 * @brief Update a tw timer
386 * @param tw_timer_wheel_t * tw timer wheel object pointer
387 * @param u32 handle timer returned by tw_timer_start
388 * @param u32 interval timer interval in ticks
390 void TW (tw_timer_update) (TWT (tw_timer_wheel) * tw, u32 handle,
394 t = pool_elt_at_index (tw->timers, handle);
395 timer_remove (tw->timers, t);
396 timer_add (tw, t, interval);
400 * @brief Initialize a tw timer wheel template instance
401 * @param tw_timer_wheel_t * tw timer wheel object pointer
402 * @param void * expired_timer_callback. Passed a u32 * vector of
403 * expired timer handles. The callback is optional.
404 * @param f64 timer_interval_in_seconds
407 TW (tw_timer_wheel_init) (TWT (tw_timer_wheel) * tw,
408 void *expired_timer_callback,
409 f64 timer_interval_in_seconds, u32 max_expirations)
412 tw_timer_wheel_slot_t *ts;
414 clib_memset (tw, 0, sizeof (*tw));
415 tw->expired_timer_callback = expired_timer_callback;
416 tw->max_expirations = max_expirations;
417 if (timer_interval_in_seconds == 0.0)
419 clib_warning ("timer interval is zero");
422 tw->timer_interval = timer_interval_in_seconds;
423 tw->ticks_per_second = 1.0 / timer_interval_in_seconds;
425 vec_validate (tw->expired_timer_handles, 0);
426 _vec_len (tw->expired_timer_handles) = 0;
428 for (ring = 0; ring < TW_TIMER_WHEELS; ring++)
430 for (slot = 0; slot < TW_SLOTS_PER_RING; slot++)
432 ts = &tw->w[ring][slot];
433 pool_get (tw->timers, t);
434 clib_memset (t, 0xff, sizeof (*t));
435 t->next = t->prev = t - tw->timers;
436 ts->head_index = t - tw->timers;
440 #if TW_OVERFLOW_VECTOR > 0
442 pool_get (tw->timers, t);
443 clib_memset (t, 0xff, sizeof (*t));
444 t->next = t->prev = t - tw->timers;
445 ts->head_index = t - tw->timers;
450 * @brief Free a tw timer wheel template instance
451 * @param tw_timer_wheel_t * tw timer wheel object pointer
453 void TW (tw_timer_wheel_free) (TWT (tw_timer_wheel) * tw)
456 tw_timer_wheel_slot_t *ts;
457 TWT (tw_timer) * head, *t;
460 for (i = 0; i < TW_TIMER_WHEELS; i++)
462 for (j = 0; j < TW_SLOTS_PER_RING; j++)
465 head = pool_elt_at_index (tw->timers, ts->head_index);
466 next_index = head->next;
468 while (next_index != ts->head_index)
470 t = pool_elt_at_index (tw->timers, next_index);
471 next_index = t->next;
472 pool_put (tw->timers, t);
474 pool_put (tw->timers, head);
478 #if TW_OVERFLOW_VECTOR > 0
480 head = pool_elt_at_index (tw->timers, ts->head_index);
481 next_index = head->next;
483 while (next_index != ts->head_index)
485 t = pool_elt_at_index (tw->timers, next_index);
486 next_index = t->next;
487 pool_put (tw->timers, t);
489 pool_put (tw->timers, head);
492 clib_memset (tw, 0, sizeof (*tw));
496 * @brief Advance a tw timer wheel. Calls the expired timer callback
497 * as needed. This routine should be called once every timer_interval seconds
498 * @param tw_timer_wheel_t * tw timer wheel template instance pointer
499 * @param f64 now the current time, e.g. from vlib_time_now(vm)
500 * @returns u32 * vector of expired user handles
503 u32 * TW (tw_timer_expire_timers_internal) (TWT (tw_timer_wheel) * tw,
505 u32 * callback_vector_arg)
508 tw_timer_wheel_slot_t *ts;
509 TWT (tw_timer) * t, *head;
510 u32 *callback_vector;
511 u32 fast_wheel_index;
513 u32 slow_wheel_index __attribute__ ((unused));
514 u32 glacier_wheel_index __attribute__ ((unused));
516 /* Called too soon to process new timer expirations? */
517 if (PREDICT_FALSE (now < tw->next_run_time))
518 return callback_vector_arg;
520 /* Number of ticks which have occurred */
521 nticks = tw->ticks_per_second * (now - tw->last_run_time);
523 return callback_vector_arg;
525 /* Remember when we ran, compute next runtime */
526 tw->next_run_time = (now + tw->timer_interval);
528 /* First call, or time jumped backwards? */
530 ((tw->last_run_time == 0.0) || (now <= tw->last_run_time)))
532 tw->last_run_time = now;
533 return callback_vector_arg;
536 if (callback_vector_arg == 0)
538 _vec_len (tw->expired_timer_handles) = 0;
539 callback_vector = tw->expired_timer_handles;
542 callback_vector = callback_vector_arg;
544 for (i = 0; i < nticks; i++)
546 fast_wheel_index = tw->current_index[TW_TIMER_RING_FAST];
547 if (TW_TIMER_WHEELS > 1)
548 slow_wheel_index = tw->current_index[TW_TIMER_RING_SLOW];
549 if (TW_TIMER_WHEELS > 2)
550 glacier_wheel_index = tw->current_index[TW_TIMER_RING_GLACIER];
552 #if TW_OVERFLOW_VECTOR > 0
553 /* Triple odometer-click? Process the overflow vector... */
554 if (PREDICT_FALSE (fast_wheel_index == TW_SLOTS_PER_RING
555 && slow_wheel_index == TW_SLOTS_PER_RING
556 && glacier_wheel_index == TW_SLOTS_PER_RING))
559 u32 new_glacier_ring_offset, new_slow_ring_offset;
560 u32 new_fast_ring_offset;
563 head = pool_elt_at_index (tw->timers, ts->head_index);
564 next_index = head->next;
566 /* Make slot empty */
567 head->next = head->prev = ts->head_index;
569 /* traverse slot, place timers wherever they go */
570 while (next_index != head - tw->timers)
572 t = pool_elt_at_index (tw->timers, next_index);
573 next_index = t->next;
575 /* Remove from the overflow vector (hammer) */
576 t->next = t->prev = ~0;
578 ASSERT (t->expiration_time >= tw->current_tick);
580 interval = t->expiration_time - tw->current_tick;
582 /* Right back onto the overflow vector? */
583 if (interval >= (1 << (3 * TW_RING_SHIFT)))
586 timer_addhead (tw->timers, ts->head_index, t - tw->timers);
589 /* Compute ring offsets */
590 new_glacier_ring_offset = interval >> (2 * TW_RING_SHIFT);
592 interval -= (new_glacier_ring_offset << (2 * TW_RING_SHIFT));
594 /* Note: the wheels are at (0,0,0), no add-with-carry needed */
595 new_slow_ring_offset = interval >> TW_RING_SHIFT;
596 interval -= (new_slow_ring_offset << TW_RING_SHIFT);
597 new_fast_ring_offset = interval & TW_RING_MASK;
598 t->slow_ring_offset = new_slow_ring_offset;
599 t->fast_ring_offset = new_fast_ring_offset;
601 /* Timer expires Right Now */
602 if (PREDICT_FALSE (t->slow_ring_offset == 0 &&
603 t->fast_ring_offset == 0 &&
604 new_glacier_ring_offset == 0))
606 vec_add1 (callback_vector, t->user_handle);
607 #if TW_START_STOP_TRACE_SIZE > 0
608 TW (tw_timer_trace) (tw, 0xfe, t->user_handle,
611 pool_put (tw->timers, t);
613 /* Timer moves to the glacier ring */
614 else if (new_glacier_ring_offset)
616 ts = &tw->w[TW_TIMER_RING_GLACIER][new_glacier_ring_offset];
617 timer_addhead (tw->timers, ts->head_index, t - tw->timers);
619 /* Timer moves to the slow ring */
620 else if (t->slow_ring_offset)
622 /* Add to slow ring */
623 ts = &tw->w[TW_TIMER_RING_SLOW][t->slow_ring_offset];
624 timer_addhead (tw->timers, ts->head_index, t - tw->timers);
626 /* Timer timer moves to the fast ring */
629 ts = &tw->w[TW_TIMER_RING_FAST][t->fast_ring_offset];
630 timer_addhead (tw->timers, ts->head_index, t - tw->timers);
631 #if TW_FAST_WHEEL_BITMAP
632 tw->fast_slot_bitmap =
633 clib_bitmap_set (tw->fast_slot_bitmap,
634 t->fast_ring_offset, 1);
641 #if TW_TIMER_WHEELS > 2
643 * Double odometer-click? Process one slot in the glacier ring...
645 if (PREDICT_FALSE (fast_wheel_index == TW_SLOTS_PER_RING
646 && slow_wheel_index == TW_SLOTS_PER_RING))
648 glacier_wheel_index %= TW_SLOTS_PER_RING;
649 ts = &tw->w[TW_TIMER_RING_GLACIER][glacier_wheel_index];
651 head = pool_elt_at_index (tw->timers, ts->head_index);
652 next_index = head->next;
654 /* Make slot empty */
655 head->next = head->prev = ts->head_index;
657 /* traverse slot, deal timers into slow ring */
658 while (next_index != head - tw->timers)
660 t = pool_elt_at_index (tw->timers, next_index);
661 next_index = t->next;
663 /* Remove from glacier ring slot (hammer) */
664 t->next = t->prev = ~0;
666 /* Timer expires Right Now */
667 if (PREDICT_FALSE (t->slow_ring_offset == 0 &&
668 t->fast_ring_offset == 0))
670 vec_add1 (callback_vector, t->user_handle);
671 #if TW_START_STOP_TRACE_SIZE > 0
672 TW (tw_timer_trace) (tw, 0xfe, t->user_handle,
675 pool_put (tw->timers, t);
677 /* Timer expires during slow-wheel tick 0 */
678 else if (PREDICT_FALSE (t->slow_ring_offset == 0))
680 ts = &tw->w[TW_TIMER_RING_FAST][t->fast_ring_offset];
681 timer_addhead (tw->timers, ts->head_index, t - tw->timers);
682 #if TW_FAST_WHEEL_BITMAP
683 tw->fast_slot_bitmap =
684 clib_bitmap_set (tw->fast_slot_bitmap,
685 t->fast_ring_offset, 1);
688 else /* typical case */
690 /* Add to slow ring */
691 ts = &tw->w[TW_TIMER_RING_SLOW][t->slow_ring_offset];
692 timer_addhead (tw->timers, ts->head_index, t - tw->timers);
698 #if TW_TIMER_WHEELS > 1
700 * Single odometer-click? Process a slot in the slow ring,
702 if (PREDICT_FALSE (fast_wheel_index == TW_SLOTS_PER_RING))
704 slow_wheel_index %= TW_SLOTS_PER_RING;
705 ts = &tw->w[TW_TIMER_RING_SLOW][slow_wheel_index];
707 head = pool_elt_at_index (tw->timers, ts->head_index);
708 next_index = head->next;
710 /* Make slot empty */
711 head->next = head->prev = ts->head_index;
713 /* traverse slot, deal timers into fast ring */
714 while (next_index != head - tw->timers)
716 t = pool_elt_at_index (tw->timers, next_index);
717 next_index = t->next;
719 /* Remove from sloe ring slot (hammer) */
720 t->next = t->prev = ~0;
722 /* Timer expires Right Now */
723 if (PREDICT_FALSE (t->fast_ring_offset == 0))
725 vec_add1 (callback_vector, t->user_handle);
726 #if TW_START_STOP_TRACE_SIZE > 0
727 TW (tw_timer_trace) (tw, 0xfe, t->user_handle,
730 pool_put (tw->timers, t);
732 else /* typical case */
734 /* Add to fast ring */
735 ts = &tw->w[TW_TIMER_RING_FAST][t->fast_ring_offset];
736 timer_addhead (tw->timers, ts->head_index, t - tw->timers);
737 #if TW_FAST_WHEEL_BITMAP
738 tw->fast_slot_bitmap =
739 clib_bitmap_set (tw->fast_slot_bitmap,
740 t->fast_ring_offset, 1);
747 /* Handle the fast ring */
748 fast_wheel_index %= TW_SLOTS_PER_RING;
749 ts = &tw->w[TW_TIMER_RING_FAST][fast_wheel_index];
751 head = pool_elt_at_index (tw->timers, ts->head_index);
752 next_index = head->next;
754 /* Make slot empty */
755 head->next = head->prev = ts->head_index;
757 /* Construct vector of expired timer handles to give the user */
758 while (next_index != ts->head_index)
760 t = pool_elt_at_index (tw->timers, next_index);
761 next_index = t->next;
762 vec_add1 (callback_vector, t->user_handle);
763 #if TW_START_STOP_TRACE_SIZE > 0
764 TW (tw_timer_trace) (tw, 0xfe, t->user_handle, t - tw->timers);
766 pool_put (tw->timers, t);
769 /* If any timers expired, tell the user */
770 if (callback_vector_arg == 0 && vec_len (callback_vector))
772 /* The callback is optional. We return the u32 * handle vector */
773 if (tw->expired_timer_callback)
775 tw->expired_timer_callback (callback_vector);
776 vec_reset_length (callback_vector);
778 tw->expired_timer_handles = callback_vector;
781 #if TW_FAST_WHEEL_BITMAP
782 tw->fast_slot_bitmap = clib_bitmap_set (tw->fast_slot_bitmap,
783 fast_wheel_index, 0);
788 tw->current_index[TW_TIMER_RING_FAST] = fast_wheel_index;
790 #if TW_TIMER_WHEELS > 1
791 if (PREDICT_FALSE (fast_wheel_index == TW_SLOTS_PER_RING))
793 tw->current_index[TW_TIMER_RING_SLOW] = slow_wheel_index;
796 #if TW_TIMER_WHEELS > 2
797 if (PREDICT_FALSE (slow_wheel_index == TW_SLOTS_PER_RING))
798 glacier_wheel_index++;
799 tw->current_index[TW_TIMER_RING_GLACIER] = glacier_wheel_index;
802 if (vec_len (callback_vector) >= tw->max_expirations)
806 if (callback_vector_arg == 0)
807 tw->expired_timer_handles = callback_vector;
809 tw->last_run_time += i * tw->timer_interval;
810 return callback_vector;
813 u32 *TW (tw_timer_expire_timers) (TWT (tw_timer_wheel) * tw, f64 now)
815 return TW (tw_timer_expire_timers_internal) (tw, now, 0 /* no vector */ );
818 u32 *TW (tw_timer_expire_timers_vec) (TWT (tw_timer_wheel) * tw, f64 now,
821 return TW (tw_timer_expire_timers_internal) (tw, now, vec);
824 #if TW_FAST_WHEEL_BITMAP
825 /** Returns an approximation to the first timer expiration in
826 * timer-ticks from "now". To avoid wasting an unjustifiable
827 * amount of time on the problem, we maintain an approximate fast-wheel slot
828 * occupancy bitmap. We don't worry about clearing fast wheel bits
829 * when timers are removed from fast wheel slots.
832 u32 TW (tw_timer_first_expires_in_ticks) (TWT (tw_timer_wheel) * tw)
834 u32 first_expiring_index, fast_ring_index;
837 #if TW_TIMER_WHEELS > 1
838 fast_ring_index = tw->current_index[TW_TIMER_RING_FAST];
839 if (fast_ring_index == TW_SLOTS_PER_RING)
842 first_expiring_index = clib_bitmap_next_set (tw->fast_slot_bitmap,
844 if (first_expiring_index == ~0)
845 first_expiring_index = TW_SLOTS_PER_RING;
849 if (clib_bitmap_is_zero (tw->fast_slot_bitmap))
850 return TW_SLOTS_PER_RING;
852 fast_ring_index = tw->current_index[TW_TIMER_RING_FAST];
853 if (fast_ring_index == TW_SLOTS_PER_RING)
856 first_expiring_index = clib_bitmap_next_set (tw->fast_slot_bitmap,
858 if (first_expiring_index == ~0 && fast_ring_index != 0)
859 first_expiring_index = clib_bitmap_first_set (tw->fast_slot_bitmap);
862 ASSERT (first_expiring_index != ~0);
864 delta = (i32) first_expiring_index - (i32) fast_ring_index;
866 delta += TW_SLOTS_PER_RING;
876 * fd.io coding-style-patch-verification: ON
879 * eval: (c-set-style "gnu")