Define to 0 to prevent the use of CaptureStackBackTrace(). JETBYTE_ADDITIONAL_BUFFER_TRACKING_CONTEXT and JETBYTE_ADDITIONAL_SOCKET_TRACKING. Socket Tools. Ever thought of writing your own Windows socket server class? Love Selection 2 Zip on this page. In this article Len shows you exactly how to do just that, including details of what a socket server.

• • • • • • Probably the easiest way to start writing your own server is to take a look at one of the. There are TCP and UDP examples and they start from the simplest echo server and build up slowly towards more advanced servers, such as SSL enabled TCP web servers and include servers that run as Windows Services and servers that expose internal monitoring via perfmon counters. This guide will assume that you have a copy of the most basic example and will explain how the server is put together, how you get it to do the work that you want and how you configure it. A simple server will usually consist of at least 3 files; a ServerMain.cpp file that puts together the objects required to run the server and configures them, and and files that provide a link between the framework and the that you will implement to act on various network events that happen during the lifetime of the connections to your server. We'll start by looking at the file.

For the simplest EchoServer this file could look something like this. CSocketServer( const std::string &welcomeMessage, const &address, const listenBacklog, &pool, &socketAllocator, &bufferAllocator, &connectionLimiter = ); First we pass in a std::string which is simply part of our simple server's 'business logic', we'll ignore that for now. Next comes an instance of which is the address that we'll be listening on. There are several concrete addressing classes that we can select from, but for now we'll assume that we're passing in an instance of which is a TCP/IPv4 address.

Notice that we could simply pass in an instance of if we wished our server to listen on a TCP/IPv6 address or if we didn't know what kind of address we'd be using (CFullAddress can construct itself from string representations of addresses and can represent any valid address type given a valid construction string). Next comes the listenBacklog which is the maximum length of the queue of pending connections. If set to SOMAXCONN, the underlying service provider responsible for the server's listening socket will set the backlog to a maximum reasonable value. Something small usually works well for most simple servers, and you can increase it if you find that your server is refusing connections.

Note that this isn't the number of connections that your server can handle, it's just the number of connections that are queing to be accepted by the server, the server accepts connections very quickly and so this queue of pending connections can usually be quite small. Next comes an instance of this is where all of the multi-threading is done. The reason that the pool is passed in rather than part of the server itself is that multiple servers can share the same pool, and, indeed, the pool can be shared with other code that performs if required. Next is an instance of, our socket allocator. This can often pool sockets for later reuse so that once the server is running with the 'normal' number of clients connecting and disconnecting there's no need to allocate memory. Likewise an instance of does the same for our data buffers. Finally there's an optional instance of.

This is a very important part of a high availability server that needs (or could) service many thousands of concurrent connections. The connection limiter can protect the machine that the server runs on from running out of essential resources, the result of which is often a, see for more details. As we can see from the body of the constructor, we pass most of these things down to the server object.

Server.Start(); server.StartAcceptingConnections(); Well, that's enough to get the server up and running and have it start accepting connections and dealing with them. All of the work happens on the server object's own thread (for accepting) and the I/O pool's threads (for the actual work of dealing with events that happen on the connections).

There's nothing else that this main thread needs to do, except hang around until the server should be shutdown. In the example servers we use an external 'off switch' in the shape of a simple MFC application with a 'stop' button on it. This application simply sets an event to shut the server down.

The code for dealing with this, and the ability to pause the acceptance of new connections, lives in in the ServerCommon library and is shown below.