lsquic_pacer.h revision 06b2a236 
1/* Copyright (c) 2017 - 2021 LiteSpeed Technologies Inc.  See LICENSE. */
2#ifndef LSQUIC_PACER_H
3#define LSQUIC_PACER_H 1
4
5struct lsquic_conn;
6
7struct pacer
8{
9    const struct lsquic_conn
10                   *pa_conn;             /* Used for logging */
11    lsquic_time_t   pa_next_sched;
12    lsquic_time_t   pa_last_delayed;
13    lsquic_time_t   pa_now;
14
15    /* All tick times are in microseconds */
16
17    unsigned        pa_clock_granularity;
18
19    unsigned        pa_burst_tokens;
20    unsigned        pa_n_scheduled;     /* Within single tick */
21    enum {
22        PA_LAST_SCHED_DELAYED   = (1 << 0),
23        PA_DELAYED_ON_TICK_IN   = (1 << 1),
24    }               pa_flags;
25#ifndef NDEBUG
26    struct {
27        unsigned        n_scheduled;
28    }               pa_stats;
29#endif
30};
31
32
33typedef lsquic_time_t (*tx_time_f)(void *ctx);
34
35void
36lsquic_pacer_init (struct pacer *, const struct lsquic_conn *,
37                                            unsigned clock_granularity);
38
39void
40lsquic_pacer_cleanup (struct pacer *);
41
42void
43lsquic_pacer_tick_in (struct pacer *, lsquic_time_t);
44
45void
46lsquic_pacer_tick_out (struct pacer *);
47
48int
49lsquic_pacer_can_schedule (struct pacer *, unsigned n_in_flight);
50
51void
52lsquic_pacer_packet_scheduled (struct pacer *pacer, unsigned n_in_flight,
53                        int in_recovery, tx_time_f tx_time, void *tx_ctx);
54
55void
56lsquic_pacer_loss_event (struct pacer *);
57
58#define lsquic_pacer_delayed(pacer) ((pacer)->pa_flags & PA_LAST_SCHED_DELAYED)
59
60#define lsquic_pacer_next_sched(pacer) (+(pacer)->pa_next_sched)
61
62int
63lsquic_pacer_can_schedule_probe (const struct pacer *,
64                                unsigned n_in_flight, lsquic_time_t tx_time);
65
66#endif
67