package wasi:clocks

/// WASI Monotonic Clock is a clock API intended to let users measure elapsed
/// time.
///
/// It is intended to be portable at least between Unix-family platforms and
/// Windows.
///
/// A monotonic clock is a clock which has an unspecified initial value, and
/// successive reads of the clock will produce non-decreasing values.
///
/// It is intended for measuring elapsed time.
interface monotonic-clock {
    use wasi:poll/poll.{pollable}

    /// A timestamp in nanoseconds.
    type instant = u64

    /// Read the current value of the clock.
    ///
    /// The clock is monotonic, therefore calling this function repeatedly will
    /// produce a sequence of non-decreasing values.
    now: func() -> instant

    /// Query the resolution of the clock.
    resolution: func() -> instant

    /// Create a `pollable` which will resolve once the specified time has been
    /// reached.
    subscribe: func(
        when: instant,
        absolute: bool
    ) -> pollable
}