/* * 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. */ #ifndef TW_SUFFIX #error do not include tw_timer_template.h directly #endif #include <vppinfra/clib.h> #include <vppinfra/pool.h> #ifndef _twt #define _twt(a,b) a##b##_t #define __twt(a,b) _twt(a,b) #define TWT(a) __twt(a,TW_SUFFIX) #define _tw(a,b) a##b #define __tw(a,b) _tw(a,b) #define TW(a) __tw(a,TW_SUFFIX) #endif /** @file @brief TW timer template header file, do not compile directly Instantiation of tw_timer_template.h generates named structures to implement specific timer wheel geometries. Choices include: number of timer wheels (currently, 1 or 2), number of slots per ring (a power of two), and the number of timers per "object handle". Internally, user object/timer handles are 32-bit integers, so if one selects 16 timers/object (4 bits), the resulting timer wheel handle is limited to 2**28 objects. Here are the specific settings required to generate a single 2048 slot wheel which supports 2 timers per object: #define TW_TIMER_WHEELS 1 #define TW_SLOTS_PER_RING 2048 #define TW_RING_SHIFT 11 #define TW_RING_MASK (TW_SLOTS_PER_RING -1) #define TW_TIMERS_PER_OBJECT 2 #define LOG2_TW_TIMERS_PER_OBJECT 1 #define TW_SUFFIX _2t_1w_2048sl See tw_timer_2t_1w_2048sl.h for a complete example. tw_timer_template.h is not intended to be #included directly. Client codes can include multiple timer geometry header files, although extreme caution would required to use the TW and TWT macros in such a case. API usage example: Initialize a two-timer, single 2048-slot wheel w/ a 1-second timer granularity: tw_timer_wheel_init_2t_1w_2048sl (&tm->single_wheel, expired_timer_single_callback, 1.0 / * timer interval * / ); Start a timer: handle = tw_timer_start_2t_1w_2048sl (&tm->single_wheel, elt_index, [0 | 1] / * timer id * / , expiration_time_in_u32_ticks); Stop a timer: tw_timer_stop_2t_1w_2048sl (&tm->single_wheel, handle); Expired timer callback: static void expired_timer_single_callback (u32 * expired_timers) { int i; u32 pool_index, timer_id; tw_timer_test_elt_t *e; tw_timer_test_main_t *tm = &tw_timer_test_main; for (i = 0; i < vec_len (expired_timers); { pool_index = expired_timers[i] & 0x7FFFFFFF; timer_id = expired_timers[i] >> 31; ASSERT (timer_id == 1); e = pool_elt_at_index (tm->test_elts, pool_index); if (e->expected_to_expire != tm->single_wheel.current_tick) { fformat (stdout, "[%d] expired at %d not %d\n", e - tm->test_elts, tm->single_wheel.current_tick, e->expected_to_expire); } pool_put (tm->test_elts, e); } } */ typedef struct { /** next, previous pool indices */ u32 next; u32 prev; #if TW_TIMER_WHEELS > 0 /** fast ring offset, only valid in the slow ring */ u16 fast_ring_offset; u16 pad; #endif /** user timer handle */ u32 user_handle; } TWT (tw_timer); /* * These structures ar used by all geometries, * so they need a private #include block... */ #ifndef __defined_tw_timer_wheel_slot__ #define __defined_tw_timer_wheel_slot__ typedef struct { /** Listhead of timers which expire in this interval */ u32 head_index; } tw_timer_wheel_slot_t; typedef enum { /** Fast timer ring ID */ TW_TIMER_RING_FAST, /** Slow timer ring ID */ TW_TIMER_RING_SLOW, } tw_ring_index_t; #endif /* __defined_tw_timer_wheel_slot__ */ typedef struct { /** Timer pool */ TWT (tw_timer) * timers; /** Next time the wheel should run */ f64 next_run_time; /** Last time the wheel ran */ f64 last_run_time; /** Timer ticks per second */ f64 ticks_per_second; /** Timer interval, also needed to avoid fp divide in speed path */ f64 timer_interval; /** current tick */ u32 current_tick; /** current wheel indices */ u32 current_index[TW_TIMER_WHEELS]; /** wheel arrays */ tw_timer_wheel_slot_t w[TW_TIMER_WHEELS][TW_SLOTS_PER_RING]; /** expired timer callback, receives a vector of handles */ void (*expired_timer_callback) (u32 * expired_timer_handles); /** vector of expired timers */ u32 *expired_timer_handles; /** maximum expirations */ u32 max_expirations; } TWT (tw_timer_wheel); u32 TW (tw_timer_start) (TWT (tw_timer_wheel) * tw, u32 pool_index, u32 timer_id, u32 interval); void TW (tw_timer_stop) (TWT (tw_timer_wheel) * tw, u32 handle); void TW (tw_timer_wheel_init) (TWT (tw_timer_wheel) * tw, void *expired_timer_callback, f64 timer_interval, u32 max_expirations); void TW (tw_timer_wheel_free) (TWT (tw_timer_wheel) * tw); u32 TW (tw_timer_expire_timers) (TWT (tw_timer_wheel) * tw, f64 now); /* * fd.io coding-style-patch-verification: ON * * Local Variables: * eval: (c-set-style "gnu") * End: */