当长时间运行的ADO.NET进程需要等待操作完成时，可以使用CoWaitForMultipleHandles函数等待线程堵塞的句柄。以下是代码示例：

using System.Runtime.InteropServices;

public void LongRunningProcess()
{
    // ADO.NET code ...

    // Wait for operation to complete
    IntPtr[] handles = { asyncResult.AsyncWaitHandle.SafeWaitHandle.DangerousGetHandle() };
    uint result = CoWaitForMultipleHandles(0x0001, 30000, 1, handles, out uint index);

    if (result == 0x00000080) // RPC_E_CALL_COMPLETE
    {
        // Operation completed
    }
    else
    {
        // Timeout or error
    }
}

[DllImport("ole32.dll")]
public static extern uint CoWaitForMultipleHandles(uint dwFlags, int dwTimeout, uint cHandles, IntPtr[] pHandles, out uint pdwIndex);