overhead

问题 I am wondering what the overhead is of having unused functions in your code. Say for example you have some debug logging, and you then give most of your objects a ToString() function that is being used in the debug logs. In a release build that debug logging is not being used. Is it then worth it removing the source code of those ToString() functions? (e.g. via Macro?) Or do they just make the executable marginally larger and otherwise don't impact performance? e.g. no speed impact? Or does

问题 I had referred this question (I changed its title). I am aware that code generation related to virtual ness are implementation specific. However, earlier question suggests that, there is an additional cost related to virtual inheritance, when calling non-virtual base method. I wrote following test codes and checked its assembly in g++ (with -O4 ): Common part struct Base { int t_size; Base (int i) : t_size(i) {} virtual ~Base () {} int size () const { return t_size; }; }; struct D1 : virtual

问题 I am studying java, and I remember reading somewhere that java objects, had some overhead inside the JVM, which was used for administration reasons by the virtual machine. So my question is, can someone tell me if and how I can get an object's total size in the HotSpot JVM, along with any overhead it may come with? 回答1: You can't get the overhead directly. The amount of overhead is implementation dependent, and can vary based on a number of factors (e.g. the precise JVM version, and whether

问题 I have read that there is some overhead to using C++ exceptions for exception handling as opposed to, say, checking return values. I'm only talking about overhead that is incurred when no exception is thrown. I'm also assuming that you would need to implement the code that actually checks the return value and does the appropriate thing, whatever would be the equivalent to what the catch block would have done. And, it's also not fair to compare code that throws exception objects with 45 state

问题 I have read that there is some overhead to using C++ exceptions for exception handling as opposed to, say, checking return values. I'm only talking about overhead that is incurred when no exception is thrown. I'm also assuming that you would need to implement the code that actually checks the return value and does the appropriate thing, whatever would be the equivalent to what the catch block would have done. And, it's also not fair to compare code that throws exception objects with 45 state

问题 For the past few days I'm getting more interested in Knockoutjs. It looks very promising because it models the MVVM pattern and WPF like bindings, but I do have some doubts whenever it bring something useful to non RIA web apps (and when I say RIA I mean complex in browser applications, let's say an ERP, anyway something a bit more complex than adding a few rows to a table and hiding one) Let's say you have a combobox with 10 items, and you need to be able to create on client side another 2

问题 I'm trying to serialize some data for a UDP packet stream and I'm getting a huge overhead from serialization. If I encode a FileData with a 1k Byte array I get back 2312 bytes. How would I reduce this overhead without encoding and decoding everything myself? [<Serializable>] type Response = | FileSize of String * int64 | FileData of int64 * byte[] with static member Decode(packet : byte[]) = use ms = new MemoryStream(packet) let bf = new BinaryFormatter() bf.Deserialize(ms) |> unbox<Response>

问题 I am currently working on network software. It has one main class, server which obviously represents a server instance. A server instance can send requests and the user is notified of the response by a callback. The code is like: class server { public: typedef boost::function<void (int duration)> callback_func; void send_request(endpoint& ep, callback_func cb); }; Now let's say that, as a user I want to the callback to know about the instance that called it, I can do the following thing: void

问题 I have a structure template that takes two types ( T and S ), and at some point uses a static_cast to convert from one type to the other. It is often the case that T and S are the same type. A simplified example of the setup: template <typename T, typename S = T> struct foo { void bar(T val) { /* ... */ some_other_function(static_cast<S>(val)); /* ... */ } }; In the case that S is the same class as T , does or can the static_cast introduce extra overhead, or is it a null operation which will

问题 I have a structure template that takes two types ( T and S ), and at some point uses a static_cast to convert from one type to the other. It is often the case that T and S are the same type. A simplified example of the setup: template <typename T, typename S = T> struct foo { void bar(T val) { /* ... */ some_other_function(static_cast<S>(val)); /* ... */ } }; In the case that S is the same class as T , does or can the static_cast introduce extra overhead, or is it a null operation which will