WithTimeout.cs

public static class GeneralExtensions {
    /// <summary>
    /// Throws an exception if the task fails to complete within a number of milliseconds from when invoked.
    /// </summary>
    /// <param name="task">The task on which to enforce the timeout</param>
    /// <param name="milliseconds">The timeout in milliseconds.</param>
    /// <param name="operationDescription">The text description that should appear in the timeout exception message.
    /// Useful for pinpointing the timed-out operation.</param>
    /// <returns>The completed task, if the task completed in time.</returns>
    /// <exception cref="TimeoutException">Thrown when the timeout is reached before the task is completed.</exception>
    /// <exception cref="ArgumentNullException">The task is null.</exception>
    /// <remarks>Does not cancel the task.  Does not guarantee very precise timing.  Does not consider the
    /// running time of the task before this call was invoked, which may be considerable
    /// (remember, most asynchronous Tasks in .NET start running immediately on creation).</remarks>
    /// <example><code>await connection.QueryAsync(...).WithTimeout(2000);</code></example>
    public static async Task WithTimeout(this Task task, int milliseconds, string? operationDescription = null)
    {
        // This was necessitated by https://github.com/StackExchange/Dapper/issues/927, but it maybe useful elsewhere too

        if (task is null) throw new ArgumentNullException(nameof(task));
        await Task.WhenAny(task, Task.Delay(milliseconds));
        if (!task.IsCompleted)
        {
            string message = $"Operation {operationDescription ?? ""} timed out after {(decimal)milliseconds / 1000.0m} seconds.";
            throw new TimeoutException(message);
        }
    }

    /// <summary>
    /// Throws an exception if the task fails to complete within a number of milliseconds from when invoked.
    /// </summary>
    /// <param name="task">The task on which to enforce the timeout</param>
    /// <param name="milliseconds">The timeout in milliseconds.</param>
    /// <param name="operationDescription">The text description that should appear in the timeout exception message.
    /// Useful for pinpointing the timed-out operation.</param>
    /// <returns>The completed task with a result, if the task completed in time.</returns>
    /// <exception cref="TimeoutException">Thrown when the timeout is reached before the task is completed.</exception>
    /// <exception cref="ArgumentNullException">The task is null.</exception>
    /// <remarks>Does not cancel the task.  Does not guarantee very precise timing.  Does not consider the
    /// running time of the task before this call was invoked, which may be considerable
    /// (remember, most asynchronous Tasks in .NET start running immediately on creation).</remarks>
    /// <example><code>int count = await connection.QueryAsync(...).WithTimeout(2000);</code></example>
    public static async Task<T> WithTimeout<T>(this Task<T> task, int milliseconds, string? operationDescription = null)
    {
        await (task as Task).WithTimeout(milliseconds, operationDescription);
        return await task;
    }
}