// file: crates/ksp-worker-api/src/stop.rs
// version: 2

/// Runtime-neutral cloneable token carrying cooperative Worker stop intent.
#[derive(Clone)]
pub struct WorkerStopToken {
    requested: std::sync::Arc<std::sync::atomic::AtomicBool>,
}

impl crate::WorkerStopToken {
    /// Creates a token with no stop request.
    #[must_use]
    pub fn new() -> Self {
        return Self { requested: std::sync::Arc::new(std::sync::atomic::AtomicBool::new(false)) };
    }

    /// Requests stop and returns `true` only for the first request shared by all clones.
    #[must_use]
    pub fn request_stop(&self) -> bool {
        return !self.requested.swap(true, std::sync::atomic::Ordering::AcqRel);
    }

    /// Reports whether stop has been requested through any clone.
    #[must_use]
    pub fn is_stop_requested(&self) -> bool {
        return self.requested.load(std::sync::atomic::Ordering::Acquire);
    }
}

impl std::default::Default for crate::WorkerStopToken {
    fn default() -> Self {
        return Self::new();
    }
}

impl std::fmt::Debug for crate::WorkerStopToken {
    fn fmt(&self, formatter: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        return formatter.debug_struct("WorkerStopToken").field("stop_requested", &self.is_stop_requested()).finish();
    }
}

#[cfg(test)]
#[path = "../unit_tests/stop.rs"]
mod tests;