#fixed code
                                public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {

        ProtobufRPC protobufPRC = method.getAnnotation(ProtobufRPC.class);
        if (protobufPRC == null) {
            throw new IllegalAccessError("Target method is not marked annotation @ProtobufPRC. method name :"
                    + method.getDeclaringClass().getName() + "." + method.getName());
        }

        String serviceName = protobufPRC.serviceName();
        String methodName = protobufPRC.methodName();
        if (StringUtils.isEmpty(methodName)) {
            methodName = method.getName();
        }
        String methodSignature = serviceName + '!' + methodName;
        RpcMethodInfo rpcMethodInfo = cachedRpcMethods.get(methodSignature);
        if (rpcMethodInfo == null) {
            throw new IllegalAccessError("Can not invoke method '" + method.getName() 
                    + "' due to not a protbufRpc method.");
        }
        
        long onceTalkTimeout = rpcMethodInfo.getOnceTalkTimeout();
        if (onceTalkTimeout <= 0) {
            // use default once talk timeout
            onceTalkTimeout = rpcClient.getRpcClientOptions().getOnceTalkTimeout();
        }
        
        BlockingRpcCallback callback = new BlockingRpcCallback();
        RpcDataPackage rpcDataPackage = buildRequestDataPackage(rpcMethodInfo, args);
        // set correlationId
        rpcDataPackage.getRpcMeta().setCorrelationId(rpcClient.getNextCorrelationId());
        
        RpcChannel rpcChannel = rpcChannelMap.get(methodSignature);
        if (rpcChannel == null) {
            throw new RuntimeException("No rpcChannel bind with serviceSignature '" + methodSignature + "'");
        }
        
        rpcChannel.doTransport(rpcDataPackage, callback, onceTalkTimeout);
        
        if (!callback.isDone()) {
            synchronized (callback) {
                while (!callback.isDone()) {
                    try {
                        callback.wait();
                    } catch (InterruptedException e) {
                        Thread.currentThread().interrupt();
                    }
                }
            }
        }
        
        RpcDataPackage message = callback.getMessage();
        
        RpcResponseMeta response = message.getRpcMeta().getResponse();
        if (response != null) {
            Integer errorCode = response.getErrorCode();
            if (!ErrorCodes.isSuccess(errorCode)) {
                String error = message.getRpcMeta().getResponse().getErrorText();
                throw new Throwable("A error occurred: errorCode=" + errorCode + " errorMessage:" + error);
            }
        }
        
        
        byte[] attachment = message.getAttachment();
        if (attachment != null) {
            ClientAttachmentHandler attachmentHandler = rpcMethodInfo.getClientAttachmentHandler();
            if (attachmentHandler != null) {
                attachmentHandler.handleResponse(attachment, serviceName, methodName, args);
            }
        }
        
        // handle response data
        byte[] data = message.getData();
        if (data == null) {
            return null;
        }
        
        return rpcMethodInfo.outputDecode(data);
    }
#vulnerable code 
                                public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {

        ProtobufRPC protobufPRC = method.getAnnotation(ProtobufRPC.class);
        if (protobufPRC == null) {
            throw new IllegalAccessError("Target method is not marked annotation @ProtobufPRC. method name :"
                    + method.getDeclaringClass().getName() + "." + method.getName());
        }

        String serviceName = protobufPRC.serviceName();
        String methodName = protobufPRC.methodName();
        if (StringUtils.isEmpty(methodName)) {
            methodName = method.getName();
        }
        String methodSignature = serviceName + '!' + methodName;
        RpcMethodInfo rpcMethodInfo = cachedRpcMethods.get(methodSignature);
        if (rpcMethodInfo == null) {
            throw new IllegalAccessError("Can not invoke method '" + method.getName() 
                    + "' due to not a protbufRpc method.");
        }
        
        long onceTalkTimeout = rpcMethodInfo.getOnceTalkTimeout();
        if (onceTalkTimeout <= 0) {
            // use default once talk timeout
            onceTalkTimeout = rpcClient.getRpcClientOptions().getOnceTalkTimeout();
        }
        
        BlockingRpcCallback callback = new BlockingRpcCallback();
        RpcDataPackage rpcDataPackage = buildRequestDataPackage(rpcMethodInfo, args);
        // set correlationId
        rpcDataPackage.getRpcMeta().setCorrelationId(rpcClient.getNextCorrelationId());
        rpcChannel.doTransport(rpcDataPackage, callback, onceTalkTimeout);
        
        if (!callback.isDone()) {
            synchronized (callback) {
                while (!callback.isDone()) {
                    try {
                        callback.wait();
                    } catch (InterruptedException e) {
                        Thread.currentThread().interrupt();
                    }
                }
            }
        }
        
        RpcDataPackage message = callback.getMessage();
        
        RpcResponseMeta response = message.getRpcMeta().getResponse();
        if (response != null) {
            Integer errorCode = response.getErrorCode();
            if (!ErrorCodes.isSuccess(errorCode)) {
                String error = message.getRpcMeta().getResponse().getErrorText();
                throw new Throwable("A error occurred: errorCode=" + errorCode + " errorMessage:" + error);
            }
        }
        
        
        byte[] attachment = message.getAttachment();
        if (attachment != null) {
            ClientAttachmentHandler attachmentHandler = rpcMethodInfo.getClientAttachmentHandler();
            if (attachmentHandler != null) {
                attachmentHandler.handleResponse(attachment, serviceName, methodName, args);
            }
        }
        
        // handle response data
        byte[] data = message.getData();
        if (data == null) {
            return null;
        }
        
        return rpcMethodInfo.outputDecode(data);
    } 
                            #location 31 
                            #vulnerability type THREAD_SAFETY_VIOLATION