Struct std::Interval

struct Interval {
    long long period_ms;
    long long next_ms;
    long long ticks;
    struct Sleep sleep;
    int started;
}

A periodic timer (tokio::time::interval): every poll that returns Ready gives the number of the tick (1, 2, 3, ...), one per 'period_ms', the first one 'period_ms' after the first poll. Unlike a plain future it is polled again after Ready — it is a stream of ticks. Missed ticks (the task was busy) are delivered back to back, then the schedule continues (tokio's MissedTickBehavior::Burst).