c# - 如何强制 WCF 线程中未处理的异常使进程崩溃？

Question

所以这是场景：

我有一个 WCF 服务，它为每个操作定义了一堆 FaultContracts。我想安排它，如果在与有效的 FaultContract 不匹配的 WCF 服务线程中引发未处理的异常，它会关闭整个进程而不仅仅是线程。（原因是我想要一个包含异常信息的故障转储，因为它与合同不匹配。）

有没有办法干净地做到这一点？我遇到的主要问题是 WCF 想要将我的所有异常转换为客户端故障，以保持服务运行；我其实是想把整个过程搞下来，这本质上意味着规避 WCF 的正常行为。

Answer 1

Environment.FailFast() 将创建故障转储；它不会运行任何挂起的 try-finally 块，也不会运行任何终结器。

Answer 2

您需要使用IErrorHandler来自定义 WCF 的错误处理行为。在调用 (ServiceHost).Open() 之前“应用行为”。

例如（在 Main() 中查找显示“serviceHost.Description.Behaviors.Add(new FailBehavior());”的行）：

class FailBehavior : IServiceBehavior
{
    public void AddBindingParameters(ServiceDescription serviceDescription, ServiceHostBase serviceHostBase, System.Collections.ObjectModel.Collection<ServiceEndpoint> endpoints, BindingParameterCollection bindingParameters)
    {
        return;
    }

    public void ApplyDispatchBehavior(ServiceDescription serviceDescription, ServiceHostBase serviceHostBase)
    {
        Console.WriteLine("The FailFast behavior has been applied.");
        var f = new FailOnError();
        foreach(ChannelDispatcher chanDisp in serviceHostBase.ChannelDispatchers)
        {
            chanDisp.ErrorHandlers.Add(f);      
        }
    }

    public void Validate(ServiceDescription serviceDescription, ServiceHostBase serviceHostBase)
    {
        return;
    }
}

class FailOnError : IErrorHandler
{
    public bool HandleError(Exception error)
    {
        // this is called for every exception -- even ungraceful disconnects
        if( !(error is CommunicationException) )
            throw new TargetInvocationException( "WCF operation failed.", error );
        else
            throw new CommunicationException( "Unexpected communication problem. (see inner exception)", error );

        // Unreachable
        //return false; // other handlers should be called
    }

    public void ProvideFault(Exception error, MessageVersion version, ref Message fault)
    {
        // Can't throw from here (it will be swallowed), and using Environment.FailFast
        // will result in all crashes going to the same WER bucket. We could create
        // another thread and throw on that, but instead I think throwing from HandleError
        // should work.

        //Console.WriteLine( "Unhandled exception: {0}", error );
        //Environment.FailFast("Unhandled exception thrown -- killing server");            
    }
}

class Program
{
    static void Main( string[] args )
    {
        Console.WriteLine( "Greetings from the server." );

        Uri uri = new Uri( "net.tcp://localhost:5678/ServerThatShouldCrash" );
        using( ServiceHost serviceHost = new ServiceHost( typeof( Server ), uri ) )
        {
            Binding binding = _CreateBinding();

            serviceHost.AddServiceEndpoint( typeof( IServer ),
                                            binding,
                                            uri );
            serviceHost.Description.Behaviors.Add(new FailBehavior());
            serviceHost.Open();

            // The service can now be accessed.
            Console.WriteLine( "The service is ready." );
            Console.WriteLine( "\nPress <ENTER> to terminate service.\n" );
            Console.ReadLine();
        }
    }

    private static Binding _CreateBinding()
    {
        NetTcpBinding netTcp = new NetTcpBinding( SecurityMode.None );
        netTcp.ReceiveTimeout = TimeSpan.MaxValue;
        netTcp.ReliableSession.InactivityTimeout = TimeSpan.MaxValue;
        return netTcp;
    } // end _CreateBinding()
}

Answer 3

Application.Exit();

这可能会做到这一点，但用户将丢失他们当时正在处理的任何内容。