kestrel_protocol_timer/

timer.rs

use crate::error::TimerError;
use crate::task::{CallbackWrapper, CompletionNotifier, TaskId, TimerCallback, TimerTask};
use crate::wheel::Wheel;
use parking_lot::Mutex;
use std::sync::Arc;
use std::time::Duration;
use tokio::sync::oneshot;
use tokio::task::JoinHandle;

/// 完成通知接收器，用于接收定时器完成通知
pub struct CompletionReceiver(pub oneshot::Receiver<()>);

/// 定时器句柄，用于管理定时器的生命周期
/// 
/// 注意：此类型不实现 Clone，以防止重复取消同一个定时器。
/// 每个定时器只应有一个所有者。
pub struct TimerHandle {
    pub(crate) task_id: TaskId,
    pub(crate) wheel: Arc<Mutex<Wheel>>,
    pub(crate) completion_rx: CompletionReceiver,
}

impl TimerHandle {
    pub(crate) fn new(task_id: TaskId, wheel: Arc<Mutex<Wheel>>, completion_rx: oneshot::Receiver<()>) -> Self {
        Self { task_id, wheel, completion_rx: CompletionReceiver(completion_rx) }
    }

    /// 取消定时器
    ///
    /// # 返回
    /// 如果任务存在且成功取消返回 true，否则返回 false
    ///
    /// # 示例
    /// ```no_run
    /// # use kestrel_protocol_timer::TimerWheel;
    /// # use std::time::Duration;
    /// # #[tokio::main]
    /// # async fn main() {
    /// let timer = TimerWheel::with_defaults().unwrap();
    /// let handle = timer.schedule_once(Duration::from_secs(1), || async {}).await.unwrap();
    /// 
    /// // 取消定时器
    /// let success = handle.cancel();
    /// println!("取消成功: {}", success);
    /// # }
    /// ```
    pub fn cancel(&self) -> bool {
        let mut wheel = self.wheel.lock();
        wheel.cancel(self.task_id)
    }

    /// 获取任务 ID
    pub fn task_id(&self) -> TaskId {
        self.task_id
    }

    /// 获取完成通知接收器的可变引用
    ///
    /// # 示例
    /// ```no_run
    /// # use kestrel_protocol_timer::TimerWheel;
    /// # use std::time::Duration;
    /// # #[tokio::main]
    /// # async fn main() {
    /// let timer = TimerWheel::with_defaults().unwrap();
    /// let handle = timer.schedule_once(Duration::from_secs(1), || async {
    ///     println!("Timer fired!");
    /// }).await.unwrap();
    /// 
    /// // 等待定时器完成（使用 into_completion_receiver 消耗句柄）
    /// handle.into_completion_receiver().0.await.ok();
    /// println!("Timer completed!");
    /// # }
    /// ```
    pub fn completion_receiver(&mut self) -> &mut CompletionReceiver {
        &mut self.completion_rx
    }

    /// 消耗句柄，返回完成通知接收器
    ///
    /// # 示例
    /// ```no_run
    /// # use kestrel_protocol_timer::TimerWheel;
    /// # use std::time::Duration;
    /// # #[tokio::main]
    /// # async fn main() {
    /// let timer = TimerWheel::with_defaults().unwrap();
    /// let handle = timer.schedule_once(Duration::from_secs(1), || async {
    ///     println!("Timer fired!");
    /// }).await.unwrap();
    /// 
    /// // 等待定时器完成
    /// handle.into_completion_receiver().0.await.ok();
    /// println!("Timer completed!");
    /// # }
    /// ```
    pub fn into_completion_receiver(self) -> CompletionReceiver {
        self.completion_rx
    }
}

/// 批量定时器句柄，用于管理批量调度的定时器
/// 
/// 通过共享 Wheel 引用减少内存开销，同时提供批量操作和迭代器访问能力。
/// 
/// 注意：此类型不实现 Clone，以防止重复取消同一批定时器。
/// 如需访问单个定时器句柄，请使用 `into_iter()` 或 `into_handles()` 进行转换。
pub struct BatchHandle {
    pub(crate) task_ids: Vec<TaskId>,
    pub(crate) wheel: Arc<Mutex<Wheel>>,
    pub(crate) completion_rxs: Vec<oneshot::Receiver<()>>,
}

impl BatchHandle {
    pub(crate) fn new(task_ids: Vec<TaskId>, wheel: Arc<Mutex<Wheel>>, completion_rxs: Vec<oneshot::Receiver<()>>) -> Self {
        Self { task_ids, wheel, completion_rxs }
    }

    /// 批量取消所有定时器
    ///
    /// # 返回
    /// 成功取消的任务数量
    ///
    /// # 示例
    /// ```no_run
    /// # use kestrel_protocol_timer::TimerWheel;
    /// # use std::time::Duration;
    /// # #[tokio::main]
    /// # async fn main() {
    /// let timer = TimerWheel::with_defaults().unwrap();
    /// let callbacks: Vec<_> = (0..10)
    ///     .map(|_| (Duration::from_secs(1), || async {}))
    ///     .collect();
    /// let batch = timer.schedule_once_batch(callbacks).await.unwrap();
    /// 
    /// let cancelled = batch.cancel_all();
    /// println!("取消了 {} 个定时器", cancelled);
    /// # }
    /// ```
    pub fn cancel_all(self) -> usize {
        let mut wheel = self.wheel.lock();
        wheel.cancel_batch(&self.task_ids)
    }

    /// 将批量句柄转换为单个定时器句柄的 Vec
    ///
    /// 消耗 BatchHandle，为每个任务创建独立的 TimerHandle。
    ///
    /// # 示例
    /// ```no_run
    /// # use kestrel_protocol_timer::TimerWheel;
    /// # use std::time::Duration;
    /// # #[tokio::main]
    /// # async fn main() {
    /// let timer = TimerWheel::with_defaults().unwrap();
    /// let callbacks: Vec<_> = (0..3)
    ///     .map(|_| (Duration::from_secs(1), || async {}))
    ///     .collect();
    /// let batch = timer.schedule_once_batch(callbacks).await.unwrap();
    /// 
    /// // 转换为独立的句柄
    /// let handles = batch.into_handles();
    /// for handle in handles {
    ///     // 可以单独操作每个句柄
    /// }
    /// # }
    /// ```
    pub fn into_handles(self) -> Vec<TimerHandle> {
        self.task_ids
            .into_iter()
            .zip(self.completion_rxs.into_iter())
            .map(|(task_id, rx)| {
                TimerHandle::new(task_id, self.wheel.clone(), rx)
            })
            .collect()
    }

    /// 获取批量任务的数量
    pub fn len(&self) -> usize {
        self.task_ids.len()
    }

    /// 检查批量任务是否为空
    pub fn is_empty(&self) -> bool {
        self.task_ids.is_empty()
    }

    /// 获取所有任务 ID 的引用
    pub fn task_ids(&self) -> &[TaskId] {
        &self.task_ids
    }

    /// 获取所有完成通知接收器的引用
    ///
    /// # 返回
    /// 所有任务的完成通知接收器列表引用
    pub fn completion_receivers(&mut self) -> &mut Vec<oneshot::Receiver<()>> {
        &mut self.completion_rxs
    }

    /// 消耗句柄，返回所有完成通知接收器
    ///
    /// # 返回
    /// 所有任务的完成通知接收器列表
    ///
    /// # 示例
    /// ```no_run
    /// # use kestrel_protocol_timer::TimerWheel;
    /// # use std::time::Duration;
    /// # #[tokio::main]
    /// # async fn main() {
    /// let timer = TimerWheel::with_defaults().unwrap();
    /// let callbacks: Vec<_> = (0..3)
    ///     .map(|_| (Duration::from_secs(1), || async {}))
    ///     .collect();
    /// let batch = timer.schedule_once_batch(callbacks).await.unwrap();
    /// 
    /// // 获取所有完成通知接收器
    /// let receivers = batch.into_completion_receivers();
    /// for rx in receivers {
    ///     tokio::spawn(async move {
    ///         if rx.await.is_ok() {
    ///             println!("A timer completed!");
    ///         }
    ///     });
    /// }
    /// # }
    /// ```
    pub fn into_completion_receivers(self) -> Vec<oneshot::Receiver<()>> {
        self.completion_rxs
    }
}

/// 实现 IntoIterator，允许直接迭代 BatchHandle
/// 
/// # 示例
/// ```no_run
/// # use kestrel_protocol_timer::TimerWheel;
/// # use std::time::Duration;
/// # #[tokio::main]
/// # async fn main() {
/// let timer = TimerWheel::with_defaults().unwrap();
/// let callbacks: Vec<_> = (0..3)
///     .map(|_| (Duration::from_secs(1), || async {}))
///     .collect();
/// let batch = timer.schedule_once_batch(callbacks).await.unwrap();
/// 
/// // 直接迭代，每个元素都是独立的 TimerHandle
/// for handle in batch {
///     // 可以单独操作每个句柄
/// }
/// # }
/// ```
impl IntoIterator for BatchHandle {
    type Item = TimerHandle;
    type IntoIter = BatchHandleIter;

    fn into_iter(self) -> Self::IntoIter {
        BatchHandleIter {
            task_ids: self.task_ids.into_iter(),
            completion_rxs: self.completion_rxs.into_iter(),
            wheel: self.wheel,
        }
    }
}

/// BatchHandle 的迭代器
pub struct BatchHandleIter {
    task_ids: std::vec::IntoIter<TaskId>,
    completion_rxs: std::vec::IntoIter<oneshot::Receiver<()>>,
    wheel: Arc<Mutex<Wheel>>,
}

impl Iterator for BatchHandleIter {
    type Item = TimerHandle;

    fn next(&mut self) -> Option<Self::Item> {
        match (self.task_ids.next(), self.completion_rxs.next()) {
            (Some(task_id), Some(rx)) => {
                Some(TimerHandle::new(task_id, self.wheel.clone(), rx))
            }
            _ => None,
        }
    }

    fn size_hint(&self) -> (usize, Option<usize>) {
        self.task_ids.size_hint()
    }
}

impl ExactSizeIterator for BatchHandleIter {
    fn len(&self) -> usize {
        self.task_ids.len()
    }
}

/// 时间轮定时器管理器
pub struct TimerWheel {
    /// 时间轮唯一标识符
    
    /// 时间轮实例（使用 Arc<Mutex> 包装以支持多线程访问）
    wheel: Arc<Mutex<Wheel>>,
    
    /// 后台 tick 循环任务句柄
    tick_handle: Option<JoinHandle<()>>,
}

impl TimerWheel {
    /// 创建新的定时器管理器
    ///
    /// # 参数
    /// - `tick_duration`: 每个 tick 的时间长度（建议 10ms）
    /// - `slot_count`: 槽位数量（必须是 2 的幂次方，建议 512 或 1024）
    ///
    /// # 返回
    /// - `Ok(Self)`: 成功创建定时器管理器
    /// - `Err(TimerError)`: 槽位数量无效
    ///
    /// # 示例
    /// ```no_run
    /// use kestrel_protocol_timer::TimerWheel;
    /// use std::time::Duration;
    ///
    /// #[tokio::main]
    /// async fn main() {
    ///     let timer = TimerWheel::new(Duration::from_millis(10), 512).unwrap();
    /// }
    /// ```
    pub fn new(tick_duration: Duration, slot_count: usize) -> Result<Self, TimerError> {
        let wheel = Wheel::new(tick_duration, slot_count)?;
        let wheel = Arc::new(Mutex::new(wheel));
        let wheel_clone = wheel.clone();

        // 启动后台 tick 循环
        let tick_handle = tokio::spawn(async move {
            Self::tick_loop(wheel_clone, tick_duration).await;
        });

        Ok(Self {
            wheel,
            tick_handle: Some(tick_handle),
        })
    }

    /// 创建带默认配置的定时器管理器
    /// - tick 时长: 10ms
    /// - 槽位数量: 512
    ///
    /// # 返回
    /// - `Ok(Self)`: 成功创建定时器管理器
    /// - `Err(TimerError)`: 创建失败（不太可能，因为使用的是有效的默认值）
    pub fn with_defaults() -> Result<Self, TimerError> {
        Self::new(Duration::from_millis(10), 512)
    }

    /// 创建与此时间轮绑定的 TimerService
    ///
    /// # 返回
    /// 绑定到此时间轮的 TimerService 实例
    ///
    /// # 示例
    /// ```no_run
    /// use kestrel_protocol_timer::TimerWheel;
    /// use std::time::Duration;
    ///
    /// #[tokio::main]
    /// async fn main() {
    ///     let timer = TimerWheel::with_defaults().unwrap();
    ///     let mut service = timer.create_service();
    ///     
    ///     // 直接通过 service 批量调度定时器
    ///     let callbacks: Vec<_> = (0..5)
    ///         .map(|_| (Duration::from_millis(100), || async {}))
    ///         .collect();
    ///     service.schedule_once_batch(callbacks).await.unwrap();
    ///     
    ///     // 接收超时通知
    ///     let mut rx = service.take_receiver().unwrap();
    ///     while let Some(task_id) = rx.recv().await {
    ///         println!("Task {:?} completed", task_id);
    ///     }
    /// }
    /// ```
    pub fn create_service(&self) -> crate::service::TimerService {
        crate::service::TimerService::new(self.wheel.clone())
    }

    /// 内部辅助方法：创建定时器句柄
    /// 
    /// 由 TimerWheel 和 TimerService 共用
    pub(crate) fn create_timer_handle_internal(
        wheel: &Arc<Mutex<Wheel>>,
        delay: Duration,
        callback: Option<CallbackWrapper>,
    ) -> Result<TimerHandle, TimerError> {
        let (completion_tx, completion_rx) = oneshot::channel();
        let notifier = CompletionNotifier(completion_tx);
        
        let task = TimerTask::once(0, 0, callback, notifier);
        
        let task_id = {
            let mut wheel_guard = wheel.lock();
            wheel_guard.insert(delay, task)
        };
        
        Ok(TimerHandle::new(task_id, wheel.clone(), completion_rx))
    }

    /// 内部辅助方法：创建批量定时器句柄
    /// 
    /// 由 TimerWheel 和 TimerService 共用
    pub(crate) fn create_batch_handle_internal<C>(
        wheel: &Arc<Mutex<Wheel>>,
        callbacks: Vec<(Duration, C)>,
    ) -> Result<BatchHandle, TimerError>
    where
        C: TimerCallback,
    {
        use std::sync::Arc;
        let mut completion_rxs = Vec::with_capacity(callbacks.len());
        
        let tasks: Vec<(Duration, TimerTask)> = callbacks
            .into_iter()
            .map(|(delay, callback)| {
                let callback_wrapper = Arc::new(callback) as CallbackWrapper;
                let (completion_tx, completion_rx) = oneshot::channel();
                completion_rxs.push(completion_rx);
                let notifier = CompletionNotifier(completion_tx);
                let task = TimerTask::once(0, 0, Some(callback_wrapper), notifier);
                (delay, task)
            })
            .collect();
        
        let task_ids = {
            let mut wheel_guard = wheel.lock();
            wheel_guard.insert_batch(tasks)
        };
        
        Ok(BatchHandle::new(task_ids, wheel.clone(), completion_rxs))
    }

    /// 调度一次性定时器
    ///
    /// # 参数
    /// - `delay`: 延迟时间
    /// - `callback`: 实现了 TimerCallback trait 的回调对象
    ///
    /// # 返回
    /// - `Ok(TimerHandle)`: 成功调度，返回定时器句柄，可用于取消定时器
    /// - `Err(TimerError)`: 内部错误
    ///
    /// # 示例
    /// ```no_run
    /// use kestrel_protocol_timer::TimerWheel;
    /// use std::time::Duration;
    /// use std::sync::Arc;
    ///
    /// #[tokio::main]
    /// async fn main() {
    ///     let timer = TimerWheel::with_defaults().unwrap();
    ///     
    ///     let handle = timer.schedule_once(Duration::from_secs(1), || async {
    ///         println!("Timer fired!");
    ///     }).await.unwrap();
    ///     
    ///     tokio::time::sleep(Duration::from_secs(2)).await;
    /// }
    /// ```
    pub async fn schedule_once<C>(&self, delay: Duration, callback: C) -> Result<TimerHandle, TimerError>
    where
        C: TimerCallback,
    {
        use std::sync::Arc;
        let callback_wrapper = Arc::new(callback) as CallbackWrapper;
        Self::create_timer_handle_internal(&self.wheel, delay, Some(callback_wrapper))
    }

    /// 批量调度一次性定时器
    ///
    /// # 参数
    /// - `tasks`: (延迟时间, 回调) 的元组列表
    ///
    /// # 返回
    /// - `Ok(BatchHandle)`: 成功调度，返回批量定时器句柄
    /// - `Err(TimerError)`: 内部错误
    ///
    /// # 性能优势
    /// - 批量处理减少锁竞争
    /// - 内部优化批量插入操作
    /// - 共享 Wheel 引用减少内存开销
    ///
    /// # 示例
    /// ```no_run
    /// use kestrel_protocol_timer::TimerWheel;
    /// use std::time::Duration;
    /// use std::sync::Arc;
    /// use std::sync::atomic::{AtomicU32, Ordering};
    ///
    /// #[tokio::main]
    /// async fn main() {
    ///     let timer = TimerWheel::with_defaults().unwrap();
    ///     let counter = Arc::new(AtomicU32::new(0));
    ///     
    ///     // 动态生成批量回调
    ///     let callbacks: Vec<(Duration, _)> = (0..3)
    ///         .map(|i| {
    ///             let counter = Arc::clone(&counter);
    ///             let delay = Duration::from_millis(100 + i * 100);
    ///             let callback = move || {
    ///                 let counter = Arc::clone(&counter);
    ///                 async move {
    ///                     counter.fetch_add(1, Ordering::SeqCst);
    ///                 }
    ///             };
    ///             (delay, callback)
    ///         })
    ///         .collect();
    ///     
    ///     let batch = timer.schedule_once_batch(callbacks).await.unwrap();
    ///     println!("Scheduled {} timers", batch.len());
    ///     
    ///     // 批量取消所有定时器
    ///     let cancelled = batch.cancel_all();
    ///     println!("Cancelled {} timers", cancelled);
    /// }
    /// ```
    pub async fn schedule_once_batch<C>(&self, callbacks: Vec<(Duration, C)>) -> Result<BatchHandle, TimerError>
    where
        C: TimerCallback,
    {
        Self::create_batch_handle_internal(&self.wheel, callbacks)
    }


    /// 调度一次性通知定时器（无回调，仅通知）
    ///
    /// # 参数
    /// - `delay`: 延迟时间
    ///
    /// # 返回
    /// - `Ok(TimerHandle)`: 成功调度，返回定时器句柄，可通过 `into_completion_receiver()` 获取通知接收器
    /// - `Err(TimerError)`: 内部错误
    ///
    /// # 示例
    /// ```no_run
    /// use kestrel_protocol_timer::TimerWheel;
    /// use std::time::Duration;
    ///
    /// #[tokio::main]
    /// async fn main() {
    ///     let timer = TimerWheel::with_defaults().unwrap();
    ///     
    ///     let handle = timer.schedule_once_notify(Duration::from_secs(1)).await.unwrap();
    ///     
    ///     // 获取完成通知接收器
    ///     handle.into_completion_receiver().0.await.ok();
    ///     println!("Timer completed!");
    /// }
    /// ```
    pub async fn schedule_once_notify(&self, delay: Duration) -> Result<TimerHandle, TimerError> {
        Self::create_timer_handle_internal(&self.wheel, delay, None)
    }

    /// 取消定时器
    ///
    /// # 参数
    /// - `task_id`: 任务 ID
    ///
    /// # 返回
    /// 如果任务存在且成功取消返回 true，否则返回 false
    pub fn cancel(&self, task_id: TaskId) -> bool {
        let mut wheel = self.wheel.lock();
        wheel.cancel(task_id)
    }

    /// 批量取消定时器
    ///
    /// # 参数
    /// - `task_ids`: 要取消的任务 ID 列表
    ///
    /// # 返回
    /// 成功取消的任务数量
    ///
    /// # 性能优势
    /// - 批量处理减少锁竞争
    /// - 内部优化批量取消操作
    ///
    /// # 示例
    /// ```no_run
    /// use kestrel_protocol_timer::TimerWheel;
    /// use std::time::Duration;
    ///
    /// #[tokio::main]
    /// async fn main() {
    ///     let timer = TimerWheel::with_defaults().unwrap();
    ///     
    ///     // 创建多个定时器
    ///     let handle1 = timer.schedule_once(Duration::from_secs(10), || async {}).await.unwrap();
    ///     let handle2 = timer.schedule_once(Duration::from_secs(10), || async {}).await.unwrap();
    ///     let handle3 = timer.schedule_once(Duration::from_secs(10), || async {}).await.unwrap();
    ///     
    ///     // 批量取消
    ///     let task_ids = vec![handle1.task_id(), handle2.task_id(), handle3.task_id()];
    ///     let cancelled = timer.cancel_batch(&task_ids);
    ///     println!("已取消 {} 个定时器", cancelled);
    /// }
    /// ```
    pub fn cancel_batch(&self, task_ids: &[TaskId]) -> usize {
        let mut wheel = self.wheel.lock();
        wheel.cancel_batch(task_ids)
    }
    
    /// 核心 tick 循环
    async fn tick_loop(wheel: Arc<Mutex<Wheel>>, tick_duration: Duration) {
        let mut interval = tokio::time::interval(tick_duration);
        interval.set_missed_tick_behavior(tokio::time::MissedTickBehavior::Skip);

        loop {
            interval.tick().await;

            // 推进时间轮并获取到期任务
            let expired_tasks = {
                let mut wheel_guard = wheel.lock();
                wheel_guard.advance()
            };

            // 执行到期任务
            for task in expired_tasks {
                let callback = task.get_callback();
                
                // 移动task的所有权来获取completion_notifier
                let notifier = task.completion_notifier;
                
                // 在独立的 tokio 任务中执行回调，并在回调完成后发送通知
                if let Some(callback) = callback {
                    tokio::spawn(async move {
                        // 执行回调
                        let future = callback.call();
                        future.await;
                        
                        // 回调执行完成后发送通知
                        let _ = notifier.0.send(());
                    });
                } else {
                    // 如果没有回调，立即发送完成通知
                    let _ = notifier.0.send(());
                }
            }
        }
    }

    /// 停止定时器管理器
    pub async fn shutdown(mut self) {
        if let Some(handle) = self.tick_handle.take() {
            handle.abort();
            let _ = handle.await;
        }
    }
}

impl Drop for TimerWheel {
    fn drop(&mut self) {
        if let Some(handle) = self.tick_handle.take() {
            handle.abort();
        }
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use std::sync::atomic::{AtomicU32, Ordering};

    #[tokio::test]
    async fn test_timer_creation() {
        let _timer = TimerWheel::with_defaults().unwrap();
    }

    #[tokio::test]
    async fn test_schedule_once() {
        use std::sync::Arc;
        let timer = TimerWheel::with_defaults().unwrap();
        let counter = Arc::new(AtomicU32::new(0));
        let counter_clone = Arc::clone(&counter);

        let _handle = timer.schedule_once(
            Duration::from_millis(50),
            move || {
                let counter = Arc::clone(&counter_clone);
                async move {
                    counter.fetch_add(1, Ordering::SeqCst);
                }
            },
        ).await.unwrap();

        // 等待定时器触发
        tokio::time::sleep(Duration::from_millis(100)).await;
        assert_eq!(counter.load(Ordering::SeqCst), 1);
    }

    #[tokio::test]
    async fn test_cancel_timer() {
        use std::sync::Arc;
        let timer = TimerWheel::with_defaults().unwrap();
        let counter = Arc::new(AtomicU32::new(0));
        let counter_clone = Arc::clone(&counter);

        let handle = timer.schedule_once(
            Duration::from_millis(100),
            move || {
                let counter = Arc::clone(&counter_clone);
                async move {
                    counter.fetch_add(1, Ordering::SeqCst);
                }
            },
        ).await.unwrap();

        // 立即取消
        let cancel_result = handle.cancel();
        assert!(cancel_result);

        // 等待足够长时间确保定时器不会触发
        tokio::time::sleep(Duration::from_millis(200)).await;
        assert_eq!(counter.load(Ordering::SeqCst), 0);
    }

    #[tokio::test]
    async fn test_cancel_immediate() {
        use std::sync::Arc;
        let timer = TimerWheel::with_defaults().unwrap();
        let counter = Arc::new(AtomicU32::new(0));
        let counter_clone = Arc::clone(&counter);

        let handle = timer.schedule_once(
            Duration::from_millis(100),
            move || {
                let counter = Arc::clone(&counter_clone);
                async move {
                    counter.fetch_add(1, Ordering::SeqCst);
                }
            },
        ).await.unwrap();

        // 立即取消
        let cancel_result = handle.cancel();
        assert!(cancel_result);

        // 等待足够长时间确保定时器不会触发
        tokio::time::sleep(Duration::from_millis(200)).await;
        assert_eq!(counter.load(Ordering::SeqCst), 0);
    }
}