我想为在Linux上使用Mono运行的控制台应用程序创建一个安全退出,但我无法找到一种解决方案,以便检测是否发送了信号或用户按下了Ctrl+C。
在Windows上,有内核函数SetConsoleCtrlHandler可以完成此任务,但这在Mono上不起作用。
如何在我的控制台应用程序上获取关闭事件以使其安全退出?
// Catch SIGINT and SIGUSR1
UnixSignal[] signals = new UnixSignal [] {
new UnixSignal (Mono.Unix.Native.Signum.SIGINT),
new UnixSignal (Mono.Unix.Native.Signum.SIGUSR1),
};
Thread signal_thread = new Thread (delegate () {
while (true) {
// Wait for a signal to be delivered
int index = UnixSignal.WaitAny (signals, -1);
Mono.Unix.Native.Signum signal = signals [index].Signum;
// Notify the main thread that a signal was received,
// you can use things like:
// Application.Invoke () for Gtk#
// Control.Invoke on Windows.Forms
// Write to a pipe created with UnixPipes for server apps.
// Use an AutoResetEvent
// For example, this works with Gtk#
Application.Invoke (delegate () { ReceivedSignal (signal); });
}});
以下是提供Unix和Windows实现的示例。请注意,使用Visual Studio时仍可以包含Mono.Posix dll。
我还添加了SIGTERM信号,因为在Unix中,当将应用程序停止/重新启动为服务时,systemd会触发此信号。
暴露退出事件的接口
public interface IExitSignal
{
event EventHandler Exit;
}
Unix实现
public class UnixExitSignal : IExitSignal
{
public event EventHandler Exit;
UnixSignal[] signals = new UnixSignal[]{
new UnixSignal(Mono.Unix.Native.Signum.SIGTERM),
new UnixSignal(Mono.Unix.Native.Signum.SIGINT),
new UnixSignal(Mono.Unix.Native.Signum.SIGUSR1)
};
public UnixExitSignal()
{
Task.Factory.StartNew(() =>
{
// blocking call to wait for any kill signal
int index = UnixSignal.WaitAny(signals, -1);
if (Exit != null)
{
Exit(null, EventArgs.Empty);
}
});
}
}
Windows实现
public class WinExitSignal : IExitSignal
{
public event EventHandler Exit;
[DllImport("Kernel32")]
public static extern bool SetConsoleCtrlHandler(HandlerRoutine Handler, bool Add);
// A delegate type to be used as the handler routine
// for SetConsoleCtrlHandler.
public delegate bool HandlerRoutine(CtrlTypes CtrlType);
// An enumerated type for the control messages
// sent to the handler routine.
public enum CtrlTypes
{
CTRL_C_EVENT = 0,
CTRL_BREAK_EVENT,
CTRL_CLOSE_EVENT,
CTRL_LOGOFF_EVENT = 5,
CTRL_SHUTDOWN_EVENT
}
/// <summary>
/// Need this as a member variable to avoid it being garbage collected.
/// </summary>
private HandlerRoutine m_hr;
public WinExitSignal()
{
m_hr = new HandlerRoutine(ConsoleCtrlCheck);
SetConsoleCtrlHandler(m_hr, true);
}
/// <summary>
/// Handle the ctrl types
/// </summary>
/// <param name="ctrlType"></param>
/// <returns></returns>
private bool ConsoleCtrlCheck(CtrlTypes ctrlType)
{
switch (ctrlType)
{
case CtrlTypes.CTRL_C_EVENT:
case CtrlTypes.CTRL_BREAK_EVENT:
case CtrlTypes.CTRL_CLOSE_EVENT:
case CtrlTypes.CTRL_LOGOFF_EVENT:
case CtrlTypes.CTRL_SHUTDOWN_EVENT:
if (Exit != null)
{
Exit(this, EventArgs.Empty);
}
break;
default:
break;
}
return true;
}
}
Application.Invoke
,直接从信号线程调用清理逻辑。 - skolimaSetConsoleCtrlHandler
用于Windows和UnixSignal
用于Linux),然后根据Environment.OSVersion.Platform
在运行时选择其中一种或另一种 - 在Unix
或MacOSX
上运行时使用UnixSignal
。 - skolima