refactor(extensions): 重构异步扩展中的超时处理机制

- 将参数从直接传入Task改为传入接收取消令牌的任务工厂方法
- 更新XML文档注释以反映新的参数设计
- 优化取消令牌处理逻辑,统一管理超时和外部取消信号
- 改进异常处理机制,确保超时情况下正确抛出TimeoutException
- 简化代码结构并提高可读性
This commit is contained in:
GeWuYou 2026-02-25 17:06:03 +08:00 committed by gewuyou
parent 850fecdff4
commit afbff7127d

View File

@ -9,88 +9,91 @@ public static class AsyncExtensions
/// 为任务添加超时限制
/// </summary>
/// <typeparam name="T">任务结果类型</typeparam>
/// <param name="task">要执行的任务</param>
/// <param name="taskFactory">接收取消令牌并返回任务的工厂方法,令牌将在超时或外部取消时触发</param>
/// <param name="timeout">超时时间</param>
/// <param name="cancellationToken">取消令牌</param>
/// <param name="cancellationToken">外部取消令牌</param>
/// <returns>任务结果</returns>
/// <exception cref="ArgumentNullException">当 task 为 null 时抛出</exception>
/// <exception cref="ArgumentNullException">当 taskFactory 为 null 时抛出</exception>
/// <exception cref="TimeoutException">当任务超时时抛出</exception>
/// <exception cref="OperationCanceledException">当操作被取消时抛出</exception>
/// <example>
/// <code>
/// var result = await SomeAsyncOperation().WithTimeout(TimeSpan.FromSeconds(5));
/// var result = await WithTimeout(
/// ct => SomeAsyncOperation(ct),
/// TimeSpan.FromSeconds(5));
/// </code>
/// </example>
public static async Task<T> WithTimeout<T>(
this Task<T> task,
Func<CancellationToken, Task<T>> taskFactory,
TimeSpan timeout,
CancellationToken cancellationToken = default)
{
ArgumentNullException.ThrowIfNull(task);
ArgumentNullException.ThrowIfNull(taskFactory);
using var timeoutCts = new CancellationTokenSource();
using var linkedCts = CancellationTokenSource.CreateLinkedTokenSource(cancellationToken, timeoutCts.Token);
// linkedCts 同时响应:超时 + 外部取消
using var linkedCts = CancellationTokenSource.CreateLinkedTokenSource(cancellationToken);
linkedCts.CancelAfter(timeout);
var delayTask = Task.Delay(timeout, linkedCts.Token);
var completedTask = await Task.WhenAny(task, delayTask);
if (completedTask == delayTask)
Task<T> task;
try
{
// 将联合令牌传入实际任务,超时时任务会收到取消信号
task = taskFactory(linkedCts.Token);
}
catch (OperationCanceledException) when (!cancellationToken.IsCancellationRequested)
{
cancellationToken.ThrowIfCancellationRequested();
throw new TimeoutException($"操作在 {timeout.TotalSeconds} 秒后超时");
}
await linkedCts.CancelAsync();
try
{
await task;
return await task.ConfigureAwait(false);
}
catch (OperationCanceledException) when (!cancellationToken.IsCancellationRequested &&
timeoutCts.Token.IsCancellationRequested)
catch (OperationCanceledException) when (!cancellationToken.IsCancellationRequested
&& linkedCts.IsCancellationRequested)
{
// ignore
// linkedCts 触发但外部未取消 → 超时
throw new TimeoutException($"操作在 {timeout.TotalSeconds} 秒后超时");
}
return task.Result;
}
/// <summary>
/// 为任务添加超时限制(无返回值版本)
/// </summary>
/// <param name="task">要执行的任务</param>
/// <param name="taskFactory">接收取消令牌并返回任务的工厂方法</param>
/// <param name="timeout">超时时间</param>
/// <param name="cancellationToken">取消令牌</param>
/// <exception cref="ArgumentNullException">当 task 为 null 时抛出</exception>
/// <param name="cancellationToken">外部取消令牌</param>
/// <exception cref="ArgumentNullException">当 taskFactory 为 null 时抛出</exception>
/// <exception cref="TimeoutException">当任务超时时抛出</exception>
/// <exception cref="OperationCanceledException">当操作被取消时抛出</exception>
public static async Task WithTimeout(
this Task task,
Func<CancellationToken, Task> taskFactory,
TimeSpan timeout,
CancellationToken cancellationToken = default)
{
ArgumentNullException.ThrowIfNull(task);
ArgumentNullException.ThrowIfNull(taskFactory);
using var timeoutCts = new CancellationTokenSource();
using var linkedCts = CancellationTokenSource.CreateLinkedTokenSource(cancellationToken, timeoutCts.Token);
using var linkedCts = CancellationTokenSource.CreateLinkedTokenSource(cancellationToken);
linkedCts.CancelAfter(timeout);
var delayTask = Task.Delay(timeout, linkedCts.Token);
var completedTask = await Task.WhenAny(task, delayTask);
if (completedTask == delayTask)
Task task;
try
{
task = taskFactory(linkedCts.Token);
}
catch (OperationCanceledException) when (!cancellationToken.IsCancellationRequested)
{
cancellationToken.ThrowIfCancellationRequested();
throw new TimeoutException($"操作在 {timeout.TotalSeconds} 秒后超时");
}
await linkedCts.CancelAsync();
try
{
await task;
await task.ConfigureAwait(false);
}
catch (OperationCanceledException) when (!cancellationToken.IsCancellationRequested &&
timeoutCts.Token.IsCancellationRequested)
catch (OperationCanceledException) when (!cancellationToken.IsCancellationRequested
&& linkedCts.IsCancellationRequested)
{
// ignore
throw new TimeoutException($"操作在 {timeout.TotalSeconds} 秒后超时");
}
}