C# 从WCF客户端内部调试NullReference异常
我们有一个WCF服务和大致如下的客户端代码:C# 从WCF客户端内部调试NullReference异常,c#,.net,wcf,exception,nullreferenceexception,C#,.net,Wcf,Exception,Nullreferenceexception,我们有一个WCF服务和大致如下的客户端代码: bool success = false; IClientChannel proxy = null; try { var client = channelFactory.CreateChannel(new EndpointAddress(url)); proxy = client as IClientChannel; proxy.Open(); client.MyWcfMethod(a, b, c);
bool success = false;
IClientChannel proxy = null;
try
{
var client = channelFactory.CreateChannel(new EndpointAddress(url));
proxy = client as IClientChannel;
proxy.Open();
client.MyWcfMethod(a, b, c);
proxy.Close();
success = true;
}
finally
{
if (!success)
proxy.Abort();
}
它似乎工作得很好,但在我们的测试版环境中,每70000次调用中就会抛出一次NullReferenceException。我们仔细地记录异常和周围的所有数据,看起来它在任何方面都不依赖于数据。如果我在异常发生后立即重复调用(只需一段时间,直到成功),则调用将顺利进行
异常非常罕见,我无法复制、跟踪或调试它。异常似乎在调用时立即抛出,没有调用服务器代码
以下是堆栈跟踪:
Object reference not set to an instance of an object. Server stack trace:
at System.Xml.Linq.ElementWriter.WriteElement(XElement e)
at System.Xml.Linq.XElement.WriteTo(XmlWriter writer)
at System.Xml.Linq.XElement.System.Xml.Serialization.IXmlSerializable.WriteXml(XmlWriter writer)
at System.Runtime.Serialization.XmlObjectSerializerWriteContext.WriteIXmlSerializable(XmlWriterDelegator xmlWriter, Object obj, XmlSerializableWriter xmlSerializableWriter)
at System.Runtime.Serialization.XmlObjectSerializerWriteContext.WriteIXmlSerializable(XmlWriterDelegator xmlWriter, Object obj)
at System.Runtime.Serialization.XmlDataContract.WriteXmlValue(XmlWriterDelegator xmlWriter, Object obj, XmlObjectSerializerWriteContext context)
at System.Runtime.Serialization.XmlObjectSerializerWriteContext.WriteDataContractValue(DataContract dataContract, XmlWriterDelegator xmlWriter, Object obj, RuntimeTypeHandle declaredTypeHandle)
at System.Runtime.Serialization.XmlObjectSerializerWriteContext.SerializeWithoutXsiType(DataContract dataContract, XmlWriterDelegator xmlWriter, Object obj, RuntimeTypeHandle declaredTypeHandle)
at System.Runtime.Serialization.XmlObjectSerializerWriteContext.InternalSerialize(XmlWriterDelegator xmlWriter, Object obj, Boolean isDeclaredType, Boolean writeXsiType, Int32 declaredTypeID, RuntimeTypeHandle declaredTypeHandle)
at WriteCallContextToXml(XmlWriterDelegator , Object , XmlObjectSerializerWriteContext , ClassDataContract )
at System.Runtime.Serialization.ClassDataContract.WriteXmlValue(XmlWriterDelegator xmlWriter, Object obj, XmlObjectSerializerWriteContext context)
at System.Runtime.Serialization.XmlObjectSerializerWriteContext.WriteDataContractValue(DataContract dataContract, XmlWriterDelegator xmlWriter, Object obj, RuntimeTypeHandle declaredTypeHandle)
at System.Runtime.Serialization.XmlObjectSerializerWriteContext.SerializeWithoutXsiType(DataContract dataContract, XmlWriterDelegator xmlWriter, Object obj, RuntimeTypeHandle declaredTypeHandle)
at System.Runtime.Serialization.DataContractSerializer.InternalWriteObjectContent(XmlWriterDelegator writer, Object graph, DataContractResolver dataContractResolver)
at System.Runtime.Serialization.DataContractSerializer.InternalWriteObjectContent(XmlWriterDelegator writer, Object graph)
at System.Runtime.Serialization.XmlObjectSerializer.WriteObjectContentHandleExceptions(XmlWriterDelegator writer, Object graph)
at System.Runtime.Serialization.DataContractSerializer.WriteObjectContent(XmlDictionaryWriter writer, Object graph)
at System.ServiceModel.Channels.XmlObjectSerializerHeader.OnWriteHeaderContents(XmlDictionaryWriter writer, MessageVersion messageVersion)
at System.ServiceModel.Channels.MessageHeader.WriteHeaderContents(XmlDictionaryWriter writer, MessageVersion messageVersion)
at System.ServiceModel.Channels.MessageHeaders.WriteHeaderContents(Int32 headerIndex, XmlDictionaryWriter writer)
at System.ServiceModel.Channels.Message.WriteMessagePreamble(XmlDictionaryWriter writer) at System.ServiceModel.Channels.Message.OnWriteMessage(XmlDictionaryWriter writer) at System.ServiceModel.Channels.BufferedMessageWriter.WriteMessage(Message message, BufferManager bufferManager, Int32 initialOffset, Int32 maxSizeQuota)
at System.ServiceModel.Channels.BinaryMessageEncoderFactory.BinaryMessageEncoder.WriteMessage(Message message, Int32 maxMessageSize, BufferManager bufferManager, Int32 messageOffset)
at System.ServiceModel.Channels.HttpOutput.SerializeBufferedMessage(Message message)
at System.ServiceModel.Channels.HttpOutput.Send(TimeSpan timeout)
at System.ServiceModel.Channels.HttpChannelFactory`1.HttpRequestChannel.HttpChannelRequest.SendRequest(Message message, TimeSpan timeout)
at System.ServiceModel.Channels.RequestChannel.Request(Message message, TimeSpan timeout) at System.ServiceModel.Dispatcher.RequestChannelBinder.Request(Message message, TimeSpan timeout) at System.ServiceModel.Channels.ServiceChannel.Call(String action, Boolean oneway, ProxyOperationRuntime operation, Object[] ins, Object[] outs, TimeSpan timeout)
at System.ServiceModel.Channels.ServiceChannelProxy.InvokeService(IMethodCallMessage methodCall, ProxyOperationRuntime operation)
at System.ServiceModel.Channels.ServiceChannelProxy.Invoke(IMessage message) Exception rethrown at [0]: at System.Runtime.Remoting.Proxies.RealProxy.HandleReturnMessage(IMessage reqMsg, IMessage retMsg)
at System.Runtime.Remoting.Proxies.RealProxy.PrivateInvoke(MessageData& msgData, Int32 type)
at IMyService.MyWcfMethod(int a, string b, double c)
at MyClientClass.Process()
关于在哪里搜索答案有什么想法吗?听起来这可能是一个线程问题-可能WCF客户端代码正在为多个调用重用同一个序列化程序实例,这会破坏一些东西 能否尝试将对
client.MyWcfMethod()
的调用放入lock
块中
e、 g:
private static readonly object _wcfSync = new object();
...
lock (_wcfSync)
{
client.MyWcfMethod(a, b, c);
}