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Diffstat (limited to 'src/vppinfra/tw_timer_template.c')
| -rw-r--r-- | src/vppinfra/tw_timer_template.c | 832 |
1 files changed, 832 insertions, 0 deletions
diff --git a/src/vppinfra/tw_timer_template.c b/src/vppinfra/tw_timer_template.c new file mode 100644 index 00000000..abad3718 --- /dev/null +++ b/src/vppinfra/tw_timer_template.c @@ -0,0 +1,832 @@ +/* + * Copyright (c) 2016 Cisco and/or its affiliates. + * 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. + */ + +/** @file + * @brief TW timer implementation TEMPLATE ONLY, do not compile directly + * + * + */ +#if TW_START_STOP_TRACE_SIZE > 0 + +void TW (tw_timer_trace) (TWT (tw_timer_wheel) * tw, u32 timer_id, + u32 pool_index, u32 handle) +{ + TWT (trace) * t = &tw->traces[tw->trace_index]; + + t->timer_id = timer_id; + t->pool_index = pool_index; + t->handle = handle; + + tw->trace_index++; + if (tw->trace_index == TW_START_STOP_TRACE_SIZE) + { + tw->trace_index = 0; + tw->trace_wrapped++; + } +} + +void TW (tw_search_trace) (TWT (tw_timer_wheel) * tw, u32 handle) +{ + u32 i, start_pos; + TWT (trace) * t; + char *s = "bogus!"; + + /* reverse search for the supplied handle */ + + start_pos = tw->trace_index; + if (start_pos == 0) + start_pos = TW_START_STOP_TRACE_SIZE - 1; + else + start_pos--; + + for (i = start_pos; i > 0; i--) + { + t = &tw->traces[i]; + if (t->handle == handle) + { + switch (t->timer_id) + { + case 0xFF: + s = "stopped"; + break; + case 0xFE: + s = "expired"; + break; + default: + s = "started"; + break; + } + fformat (stderr, "handle 0x%x (%d) %s at trace %d\n", + handle, handle, s, i); + } + } + if (tw->trace_wrapped > 0) + { + for (i = TW_START_STOP_TRACE_SIZE; i >= tw->trace_index; i--) + { + t = &tw->traces[i]; + if (t->handle == handle) + { + switch (t->timer_id) + { + case 0xFF: + s = "stopped"; + break; + case 0xFE: + s = "expired"; + break; + default: + s = "started"; + break; + } + fformat (stderr, "handle 0x%x (%d) %s at trace %d\n", + handle, handle, s, i); + } + } + } +} +#endif /* TW_START_STOP_TRACE_SIZE > 0 */ + +static inline u32 +TW (make_internal_timer_handle) (u32 pool_index, u32 timer_id) +{ + u32 handle; + + ASSERT (timer_id < TW_TIMERS_PER_OBJECT); +#if LOG2_TW_TIMERS_PER_OBJECT > 0 + ASSERT (pool_index < (1 << (32 - LOG2_TW_TIMERS_PER_OBJECT))); + + handle = (timer_id << (32 - LOG2_TW_TIMERS_PER_OBJECT)) | (pool_index); +#else + handle = pool_index; +#endif + return handle; +} + +static inline void +timer_addhead (TWT (tw_timer) * pool, u32 head_index, u32 new_index) +{ + TWT (tw_timer) * head = pool_elt_at_index (pool, head_index); + TWT (tw_timer) * old_first; + u32 old_first_index; + TWT (tw_timer) * new; + + new = pool_elt_at_index (pool, new_index); + + if (PREDICT_FALSE (head->next == head_index)) + { + head->next = head->prev = new_index; + new->next = new->prev = head_index; + return; + } + + old_first_index = head->next; + old_first = pool_elt_at_index (pool, old_first_index); + + new->next = old_first_index; + new->prev = old_first->prev; + old_first->prev = new_index; + head->next = new_index; +} + +static inline void +timer_remove (TWT (tw_timer) * pool, u32 index) +{ + TWT (tw_timer) * elt = pool_elt_at_index (pool, index); + TWT (tw_timer) * next_elt, *prev_elt; + + ASSERT (elt->user_handle != ~0); + + next_elt = pool_elt_at_index (pool, elt->next); + prev_elt = pool_elt_at_index (pool, elt->prev); + + next_elt->prev = elt->prev; + prev_elt->next = elt->next; + + elt->prev = elt->next = ~0; +} + +/** + * @brief Start a Tw Timer + * @param tw_timer_wheel_t * tw timer wheel object pointer + * @param u32 pool_index user pool index, presumably for a tw session + * @param u32 timer_id app-specific timer ID. 4 bits. + * @param u64 interval timer interval in ticks + * @returns handle needed to cancel the timer + */ +u32 +TW (tw_timer_start) (TWT (tw_timer_wheel) * tw, u32 pool_index, u32 timer_id, + u64 interval) +{ +#if TW_TIMER_WHEELS > 1 + u16 slow_ring_offset; + u32 carry; +#endif +#if TW_TIMER_WHEELS > 2 + u16 glacier_ring_offset; +#endif +#if TW_OVERFLOW_VECTOR > 0 + u64 interval_plus_time_to_wrap, triple_wrap_mask; +#endif + u16 fast_ring_offset; + tw_timer_wheel_slot_t *ts; + TWT (tw_timer) * t; + + ASSERT (interval); + + pool_get (tw->timers, t); + memset (t, 0xff, sizeof (*t)); + + t->user_handle = TW (make_internal_timer_handle) (pool_index, timer_id); + + /* Factor interval into 1..3 wheel offsets */ +#if TW_TIMER_WHEELS > 2 +#if TW_OVERFLOW_VECTOR > 0 + /* + * This is tricky. Put a timer onto the overflow + * vector if the interval PLUS the time + * until the next triple-wrap exceeds one full revolution + * of all three wheels. + */ + triple_wrap_mask = (1 << (3 * TW_RING_SHIFT)) - 1; + interval_plus_time_to_wrap = + interval + (tw->current_tick & triple_wrap_mask); + if ((interval_plus_time_to_wrap >= 1 << (3 * TW_RING_SHIFT))) + { + t->expiration_time = tw->current_tick + interval; + ts = &tw->overflow; + timer_addhead (tw->timers, ts->head_index, t - tw->timers); +#if TW_START_STOP_TRACE_SIZE > 0 + TW (tw_timer_trace) (tw, timer_id, pool_index, t - tw->timers); +#endif + return t - tw->timers; + } +#endif + + glacier_ring_offset = interval >> (2 * TW_RING_SHIFT); + ASSERT ((u64) glacier_ring_offset < TW_SLOTS_PER_RING); + interval -= (((u64) glacier_ring_offset) << (2 * TW_RING_SHIFT)); +#endif +#if TW_TIMER_WHEELS > 1 + slow_ring_offset = interval >> TW_RING_SHIFT; + ASSERT ((u64) slow_ring_offset < TW_SLOTS_PER_RING); + interval -= (((u64) slow_ring_offset) << TW_RING_SHIFT); +#endif + fast_ring_offset = interval & TW_RING_MASK; + + /* + * Account for the current wheel positions(s) + * This is made slightly complicated by the fact that the current + * index vector will contain (TW_SLOTS_PER_RING, ...) when + * the actual position is (0, ...) + */ + + fast_ring_offset += tw->current_index[TW_TIMER_RING_FAST] & TW_RING_MASK; + +#if TW_TIMER_WHEELS > 1 + carry = fast_ring_offset >= TW_SLOTS_PER_RING ? 1 : 0; + fast_ring_offset %= TW_SLOTS_PER_RING; + slow_ring_offset += (tw->current_index[TW_TIMER_RING_SLOW] & TW_RING_MASK) + + carry; + carry = slow_ring_offset >= TW_SLOTS_PER_RING ? 1 : 0; + slow_ring_offset %= TW_SLOTS_PER_RING; +#endif + +#if TW_TIMER_WHEELS > 2 + glacier_ring_offset += + (tw->current_index[TW_TIMER_RING_GLACIER] & TW_RING_MASK) + carry; + glacier_ring_offset %= TW_SLOTS_PER_RING; +#endif + +#if TW_TIMER_WHEELS > 2 + if (glacier_ring_offset != + (tw->current_index[TW_TIMER_RING_GLACIER] & TW_RING_MASK)) + { + /* We'll need slow and fast ring offsets later */ + t->slow_ring_offset = slow_ring_offset; + t->fast_ring_offset = fast_ring_offset; + + ts = &tw->w[TW_TIMER_RING_GLACIER][glacier_ring_offset]; + + timer_addhead (tw->timers, ts->head_index, t - tw->timers); +#if TW_START_STOP_TRACE_SIZE > 0 + TW (tw_timer_trace) (tw, timer_id, pool_index, t - tw->timers); +#endif + return t - tw->timers; + } +#endif + +#if TW_TIMER_WHEELS > 1 + /* Timer expires more than 51.2 seconds from now? */ + if (slow_ring_offset != + (tw->current_index[TW_TIMER_RING_SLOW] & TW_RING_MASK)) + { + /* We'll need the fast ring offset later... */ + t->fast_ring_offset = fast_ring_offset; + + ts = &tw->w[TW_TIMER_RING_SLOW][slow_ring_offset]; + + timer_addhead (tw->timers, ts->head_index, t - tw->timers); +#if TW_START_STOP_TRACE_SIZE > 0 + TW (tw_timer_trace) (tw, timer_id, pool_index, t - tw->timers); +#endif + return t - tw->timers; + } +#else + fast_ring_offset %= TW_SLOTS_PER_RING; +#endif + + /* Timer expires less than one fast-ring revolution from now */ + ts = &tw->w[TW_TIMER_RING_FAST][fast_ring_offset]; + + timer_addhead (tw->timers, ts->head_index, t - tw->timers); + +#if TW_FAST_WHEEL_BITMAP + tw->fast_slot_bitmap = clib_bitmap_set (tw->fast_slot_bitmap, + fast_ring_offset, 1); +#endif +#if TW_START_STOP_TRACE_SIZE > 0 + TW (tw_timer_trace) (tw, timer_id, pool_index, t - tw->timers); +#endif + return t - tw->timers; +} + +#if TW_TIMER_SCAN_FOR_HANDLE > 0 +int TW (scan_for_handle) (TWT (tw_timer_wheel) * tw, u32 handle) +{ + int i, j; + tw_timer_wheel_slot_t *ts; + TWT (tw_timer) * t, *head; + u32 next_index; + int rv = 0; + + for (i = 0; i < TW_TIMER_WHEELS; i++) + { + for (j = 0; j < TW_SLOTS_PER_RING; j++) + { + ts = &tw->w[i][j]; + head = pool_elt_at_index (tw->timers, ts->head_index); + next_index = head->next; + + while (next_index != ts->head_index) + { + t = pool_elt_at_index (tw->timers, next_index); + if (next_index == handle) + { + clib_warning ("handle %d found in ring %d slot %d", + handle, i, j); + clib_warning ("user handle 0x%x", t->user_handle); + rv = 1; + } + next_index = t->next; + } + } + } + return rv; +} +#endif /* TW_TIMER_SCAN_FOR_HANDLE */ + +/** + * @brief Stop a tw timer + * @param tw_timer_wheel_t * tw timer wheel object pointer + * @param u32 handle timer cancellation returned by tw_timer_start + */ +void TW (tw_timer_stop) (TWT (tw_timer_wheel) * tw, u32 handle) +{ + TWT (tw_timer) * t; + +#if TW_TIMER_ALLOW_DUPLICATE_STOP + /* + * A vlib process may have its timer expire, and receive + * an event before the expiration is processed. + * That results in a duplicate tw_timer_stop. + */ + if (pool_is_free_index (tw->timers, handle)) + return; +#endif +#if TW_START_STOP_TRACE_SIZE > 0 + TW (tw_timer_trace) (tw, ~0, ~0, handle); +#endif + + t = pool_elt_at_index (tw->timers, handle); + + /* in case of idiotic handle (e.g. passing a listhead index) */ + ASSERT (t->user_handle != ~0); + + timer_remove (tw->timers, handle); + + pool_put_index (tw->timers, handle); +} + +/** + * @brief Initialize a tw timer wheel template instance + * @param tw_timer_wheel_t * tw timer wheel object pointer + * @param void * expired_timer_callback. Passed a u32 * vector of + * expired timer handles. The callback is optional. + * @param f64 timer_interval_in_seconds + */ +void +TW (tw_timer_wheel_init) (TWT (tw_timer_wheel) * tw, + void *expired_timer_callback, + f64 timer_interval_in_seconds, u32 max_expirations) +{ + int ring, slot; + tw_timer_wheel_slot_t *ts; + TWT (tw_timer) * t; + memset (tw, 0, sizeof (*tw)); + tw->expired_timer_callback = expired_timer_callback; + tw->max_expirations = max_expirations; + if (timer_interval_in_seconds == 0.0) + { + clib_warning ("timer interval is zero"); + abort (); + } + tw->timer_interval = timer_interval_in_seconds; + tw->ticks_per_second = 1.0 / timer_interval_in_seconds; + tw->first_expires_tick = ~0ULL; + + vec_validate (tw->expired_timer_handles, 0); + _vec_len (tw->expired_timer_handles) = 0; + + for (ring = 0; ring < TW_TIMER_WHEELS; ring++) + { + for (slot = 0; slot < TW_SLOTS_PER_RING; slot++) + { + ts = &tw->w[ring][slot]; + pool_get (tw->timers, t); + memset (t, 0xff, sizeof (*t)); + t->next = t->prev = t - tw->timers; + ts->head_index = t - tw->timers; + } + } + +#if TW_OVERFLOW_VECTOR > 0 + ts = &tw->overflow; + pool_get (tw->timers, t); + memset (t, 0xff, sizeof (*t)); + t->next = t->prev = t - tw->timers; + ts->head_index = t - tw->timers; +#endif +} + +/** + * @brief Free a tw timer wheel template instance + * @param tw_timer_wheel_t * tw timer wheel object pointer + */ +void TW (tw_timer_wheel_free) (TWT (tw_timer_wheel) * tw) +{ + int i, j; + tw_timer_wheel_slot_t *ts; + TWT (tw_timer) * head, *t; + u32 next_index; + + for (i = 0; i < TW_TIMER_WHEELS; i++) + { + for (j = 0; j < TW_SLOTS_PER_RING; j++) + { + ts = &tw->w[i][j]; + head = pool_elt_at_index (tw->timers, ts->head_index); + next_index = head->next; + + while (next_index != ts->head_index) + { + t = pool_elt_at_index (tw->timers, next_index); + next_index = t->next; + pool_put (tw->timers, t); + } + pool_put (tw->timers, head); + } + } + +#if TW_OVERFLOW_VECVOR > 0 + ts = &tw->overflow; + head = pool_elt_at_index (tw->timers, ts->head_index); + next_index = head->next; + + while (next_index != ts->head_index) + { + t = pool_elt_at_index (tw->timers, next_index); + next_index = t->next; + pool_put (tw->timers, t); + } + pool_put (tw->timers, head); +#endif + + memset (tw, 0, sizeof (*tw)); +} + +/** + * @brief Advance a tw timer wheel. Calls the expired timer callback + * as needed. This routine should be called once every timer_interval seconds + * @param tw_timer_wheel_t * tw timer wheel template instance pointer + * @param f64 now the current time, e.g. from vlib_time_now(vm) + * @returns u32 * vector of expired user handles + */ +static inline + u32 * TW (tw_timer_expire_timers_internal) (TWT (tw_timer_wheel) * tw, + f64 now, + u32 * callback_vector_arg) +{ + u32 nticks, i; + tw_timer_wheel_slot_t *ts; + TWT (tw_timer) * t, *head; + u32 *callback_vector; + u32 fast_wheel_index; + u32 next_index; + u32 slow_wheel_index __attribute__ ((unused)); + u32 glacier_wheel_index __attribute__ ((unused)); + + /* Shouldn't happen */ + if (PREDICT_FALSE (now < tw->next_run_time)) + return callback_vector_arg; + + /* Number of ticks which have occurred */ + nticks = tw->ticks_per_second * (now - tw->last_run_time); + if (nticks == 0) + return callback_vector_arg; + + /* Remember when we ran, compute next runtime */ + tw->next_run_time = (now + tw->timer_interval); + + if (callback_vector_arg == 0) + { + _vec_len (tw->expired_timer_handles) = 0; + callback_vector = tw->expired_timer_handles; + } + else + callback_vector = callback_vector_arg; + + for (i = 0; i < nticks; i++) + { + fast_wheel_index = tw->current_index[TW_TIMER_RING_FAST]; + if (TW_TIMER_WHEELS > 1) + slow_wheel_index = tw->current_index[TW_TIMER_RING_SLOW]; + if (TW_TIMER_WHEELS > 2) + glacier_wheel_index = tw->current_index[TW_TIMER_RING_GLACIER]; + +#if TW_OVERFLOW_VECTOR > 0 + /* Triple odometer-click? Process the overflow vector... */ + if (PREDICT_FALSE (fast_wheel_index == TW_SLOTS_PER_RING + && slow_wheel_index == TW_SLOTS_PER_RING + && glacier_wheel_index == TW_SLOTS_PER_RING)) + { + u64 interval; + u32 new_glacier_ring_offset, new_slow_ring_offset; + u32 new_fast_ring_offset; + + ts = &tw->overflow; + head = pool_elt_at_index (tw->timers, ts->head_index); + next_index = head->next; + + /* Make slot empty */ + head->next = head->prev = ts->head_index; + + /* traverse slot, place timers wherever they go */ + while (next_index != head - tw->timers) + { + t = pool_elt_at_index (tw->timers, next_index); + next_index = t->next; + + /* Remove from the overflow vector (hammer) */ + t->next = t->prev = ~0; + + ASSERT (t->expiration_time >= tw->current_tick); + + interval = t->expiration_time - tw->current_tick; + + /* Right back onto the overflow vector? */ + if (interval >= (1 << (3 * TW_RING_SHIFT))) + { + ts = &tw->overflow; + timer_addhead (tw->timers, ts->head_index, t - tw->timers); + continue; + } + /* Compute ring offsets */ + new_glacier_ring_offset = interval >> (2 * TW_RING_SHIFT); + + interval -= (new_glacier_ring_offset << (2 * TW_RING_SHIFT)); + + /* Note: the wheels are at (0,0,0), no add-with-carry needed */ + new_slow_ring_offset = interval >> TW_RING_SHIFT; + interval -= (new_slow_ring_offset << TW_RING_SHIFT); + new_fast_ring_offset = interval & TW_RING_MASK; + t->slow_ring_offset = new_slow_ring_offset; + t->fast_ring_offset = new_fast_ring_offset; + + /* Timer expires Right Now */ + if (PREDICT_FALSE (t->slow_ring_offset == 0 && + t->fast_ring_offset == 0 && + new_glacier_ring_offset == 0)) + { + vec_add1 (callback_vector, t->user_handle); +#if TW_START_STOP_TRACE_SIZE > 0 + TW (tw_timer_trace) (tw, 0xfe, t->user_handle, + t - tw->timers); +#endif + pool_put (tw->timers, t); + } + /* Timer moves to the glacier ring */ + else if (new_glacier_ring_offset) + { + ts = &tw->w[TW_TIMER_RING_GLACIER][new_glacier_ring_offset]; + timer_addhead (tw->timers, ts->head_index, t - tw->timers); + } + /* Timer moves to the slow ring */ + else if (t->slow_ring_offset) + { + /* Add to slow ring */ + ts = &tw->w[TW_TIMER_RING_SLOW][t->slow_ring_offset]; + timer_addhead (tw->timers, ts->head_index, t - tw->timers); + } + /* Timer timer moves to the fast ring */ + else + { + ts = &tw->w[TW_TIMER_RING_FAST][t->fast_ring_offset]; + timer_addhead (tw->timers, ts->head_index, t - tw->timers); +#if TW_FAST_WHEEL_BITMAP + tw->fast_slot_bitmap = + clib_bitmap_set (tw->fast_slot_bitmap, + t->fast_ring_offset, 1); +#endif + } + } + } +#endif + +#if TW_TIMER_WHEELS > 2 + /* + * Double odometer-click? Process one slot in the glacier ring... + */ + if (PREDICT_FALSE (fast_wheel_index == TW_SLOTS_PER_RING + && slow_wheel_index == TW_SLOTS_PER_RING)) + { + glacier_wheel_index %= TW_SLOTS_PER_RING; + ts = &tw->w[TW_TIMER_RING_GLACIER][glacier_wheel_index]; + + head = pool_elt_at_index (tw->timers, ts->head_index); + next_index = head->next; + + /* Make slot empty */ + head->next = head->prev = ts->head_index; + + /* traverse slot, deal timers into slow ring */ + while (next_index != head - tw->timers) + { + t = pool_elt_at_index (tw->timers, next_index); + next_index = t->next; + + /* Remove from glacier ring slot (hammer) */ + t->next = t->prev = ~0; + + /* Timer expires Right Now */ + if (PREDICT_FALSE (t->slow_ring_offset == 0 && + t->fast_ring_offset == 0)) + { + vec_add1 (callback_vector, t->user_handle); +#if TW_START_STOP_TRACE_SIZE > 0 + TW (tw_timer_trace) (tw, 0xfe, t->user_handle, + t - tw->timers); +#endif + pool_put (tw->timers, t); + } + /* Timer expires during slow-wheel tick 0 */ + else if (PREDICT_FALSE (t->slow_ring_offset == 0)) + { + ts = &tw->w[TW_TIMER_RING_FAST][t->fast_ring_offset]; + timer_addhead (tw->timers, ts->head_index, t - tw->timers); +#if TW_FAST_WHEEL_BITMAP + tw->fast_slot_bitmap = + clib_bitmap_set (tw->fast_slot_bitmap, + t->fast_ring_offset, 1); +#endif + } + else /* typical case */ + { + /* Add to slow ring */ + ts = &tw->w[TW_TIMER_RING_SLOW][t->slow_ring_offset]; + timer_addhead (tw->timers, ts->head_index, t - tw->timers); + } + } + } +#endif + +#if TW_TIMER_WHEELS > 1 + /* + * Single odometer-click? Process a slot in the slow ring, + */ + if (PREDICT_FALSE (fast_wheel_index == TW_SLOTS_PER_RING)) + { + slow_wheel_index %= TW_SLOTS_PER_RING; + ts = &tw->w[TW_TIMER_RING_SLOW][slow_wheel_index]; + + head = pool_elt_at_index (tw->timers, ts->head_index); + next_index = head->next; + + /* Make slot empty */ + head->next = head->prev = ts->head_index; + + /* traverse slot, deal timers into fast ring */ + while (next_index != head - tw->timers) + { + t = pool_elt_at_index (tw->timers, next_index); + next_index = t->next; + + /* Remove from sloe ring slot (hammer) */ + t->next = t->prev = ~0; + + /* Timer expires Right Now */ + if (PREDICT_FALSE (t->fast_ring_offset == 0)) + { + vec_add1 (callback_vector, t->user_handle); +#if TW_START_STOP_TRACE_SIZE > 0 + TW (tw_timer_trace) (tw, 0xfe, t->user_handle, + t - tw->timers); +#endif + pool_put (tw->timers, t); + } + else /* typical case */ + { + /* Add to fast ring */ + ts = &tw->w[TW_TIMER_RING_FAST][t->fast_ring_offset]; + timer_addhead (tw->timers, ts->head_index, t - tw->timers); +#if TW_FAST_WHEEL_BITMAP + tw->fast_slot_bitmap = + clib_bitmap_set (tw->fast_slot_bitmap, + t->fast_ring_offset, 1); +#endif + } + } + } +#endif + + /* Handle the fast ring */ + fast_wheel_index %= TW_SLOTS_PER_RING; + ts = &tw->w[TW_TIMER_RING_FAST][fast_wheel_index]; + + head = pool_elt_at_index (tw->timers, ts->head_index); + next_index = head->next; + + /* Make slot empty */ + head->next = head->prev = ts->head_index; + + /* Construct vector of expired timer handles to give the user */ + while (next_index != ts->head_index) + { + t = pool_elt_at_index (tw->timers, next_index); + next_index = t->next; + vec_add1 (callback_vector, t->user_handle); +#if TW_START_STOP_TRACE_SIZE > 0 + TW (tw_timer_trace) (tw, 0xfe, t->user_handle, t - tw->timers); +#endif + pool_put (tw->timers, t); + } + + /* If any timers expired, tell the user */ + if (callback_vector_arg == 0 && vec_len (callback_vector)) + { + /* The callback is optional. We return the u32 * handle vector */ + if (tw->expired_timer_callback) + tw->expired_timer_callback (callback_vector); + tw->expired_timer_handles = callback_vector; + } + +#if TW_FAST_WHEEL_BITMAP + tw->fast_slot_bitmap = clib_bitmap_set (tw->fast_slot_bitmap, + fast_wheel_index, 0); +#endif + + tw->current_tick++; + fast_wheel_index++; + tw->current_index[TW_TIMER_RING_FAST] = fast_wheel_index; + +#if TW_TIMER_WHEELS > 1 + if (PREDICT_FALSE (fast_wheel_index == TW_SLOTS_PER_RING)) + slow_wheel_index++; + tw->current_index[TW_TIMER_RING_SLOW] = slow_wheel_index; +#endif + +#if TW_TIMER_WHEELS > 2 + if (PREDICT_FALSE (slow_wheel_index == TW_SLOTS_PER_RING)) + glacier_wheel_index++; + tw->current_index[TW_TIMER_RING_GLACIER] = glacier_wheel_index; +#endif + + if (vec_len (callback_vector) >= tw->max_expirations) + break; + } + + if (callback_vector_arg == 0) + tw->expired_timer_handles = callback_vector; + + tw->last_run_time += i * tw->timer_interval; + return callback_vector; +} + +u32 *TW (tw_timer_expire_timers) (TWT (tw_timer_wheel) * tw, f64 now) +{ + return TW (tw_timer_expire_timers_internal) (tw, now, 0 /* no vector */ ); +} + +u32 *TW (tw_timer_expire_timers_vec) (TWT (tw_timer_wheel) * tw, f64 now, + u32 * vec) +{ + return TW (tw_timer_expire_timers_internal) (tw, now, vec); +} + +#if TW_FAST_WHEEL_BITMAP +/** Returns an approximation to the first timer expiration in + * timer-ticks from "now". To avoid wasting an unjustifiable + * amount of time on the problem, we maintain an approximate fast-wheel slot + * occupancy bitmap. We don't worry about clearing fast wheel bits + * when timers are removed from fast wheel slots. + */ + +u32 TW (tw_timer_first_expires_in_ticks) (TWT (tw_timer_wheel) * tw) +{ + u32 first_expiring_index, fast_ring_index; + i32 delta; + + if (clib_bitmap_is_zero (tw->fast_slot_bitmap)) + return TW_SLOTS_PER_RING; + + fast_ring_index = tw->current_index[TW_TIMER_RING_FAST]; + if (fast_ring_index == TW_SLOTS_PER_RING) + fast_ring_index = 0; + + first_expiring_index = clib_bitmap_next_set (tw->fast_slot_bitmap, + fast_ring_index); + if (first_expiring_index == ~0 && fast_ring_index != 0) + first_expiring_index = clib_bitmap_first_set (tw->fast_slot_bitmap); + + ASSERT (first_expiring_index != ~0); + + delta = (i32) first_expiring_index - (i32) fast_ring_index; + if (delta < 0) + delta += TW_SLOTS_PER_RING; + + ASSERT (delta >= 0); + + return (u32) delta; +} + +#endif + +/* + * fd.io coding-style-patch-verification: ON + * + * Local Variables: + * eval: (c-set-style "gnu") + * End: + */ |