// Koru Standard Library: the `waits` part of time.kz.
// Joined via `~part waits` in time.kz; merged into the module at load.
//
// PUMP WAITS
//
// What a `std/pump:run` `! idle` arm reaches for. Three shapes because a dead
// pass is waited three honest ways:
//
//   sleep-us   — a fixed wait finer than sleep-ms, for a sub-millisecond spin
//                budget on a busy machine.
//   sleep-until — wait to a monotonic deadline (same `now()` epoch). A
//                deadline, not a duration: composable with anything that knows
//                when it next wants to run.
//   pace       — the frame-pacer. `last` is the boundary you last waited to
//                (start at `std/time:now()`); `pace` sleeps until
//                `last + period` and returns that boundary, so the next call
//                paces off the SCHEDULE, not off when the kernel happened to
//                wake you — a 60 Hz `! tick` that never drifts.
//
//   ! idle |> std/time:sleep-ms(ms: 2)
//   ! idle |> std/time:pace(period: 16_666_667, last: tick_ns): tick_ns
//
// Sleep for specified microseconds
~[runtime] pub tor sleep-us { us: u64 }

// Sleep until a monotonic deadline (nanoseconds, `std/time:now()` epoch).
// A deadline already past returns without sleeping — a late caller is not a
// reason to wait longer.
~[runtime] pub tor sleep-until { deadline: i128 }

// Sleep until `last + period` and return that boundary — drift-free pacing
// for a periodic wait. When the schedule already ran late the return is the
// next boundary still ahead, so a stalled caller resumes on a FUTURE tick
// rather than paying catch-up sleeps.
~[runtime] pub tor pace { period: i128, last: i128 } -> i128