added local copies of builder in invokeMethod for thread safety

Author: =

src/communication/RpcClient.cpp

@@ -208,13 +208,17 @@ RpcClient::InvokeHandle RpcClient::invokeMethod(v1::UMessage&& request,
 RpcClient::InvokeHandle RpcClient::invokeMethod(
     const v1::UUri& method, datamodel::builder::Payload&& payload,
     Callback&& callback) {
-	return invokeMethod(builder_.withMethod(method).build(std::move(payload)),
+	//makes a local copy of the builder to make this call thread safe
+	auto local_builder = builder_;
+	return invokeMethod(local_builder.withMethod(method).build(std::move(payload)),
 	                    std::move(callback));
 }
 
 RpcClient::InvokeHandle RpcClient::invokeMethod(const v1::UUri& method,
                                                 Callback&& callback) {
-	return invokeMethod(builder_.withMethod(method).build(),
+	//makes a local copy of the builder to make this call thread safe
+	auto local_builder = builder_;
+	return invokeMethod(local_builder.withMethod(method).build(),
 	                    std::move(callback));
 }