Sockets sample

The sockets sample demonstrates how to use the communication facilities provided by wxSocket. There are two different applications in this sample: a server, which is implemented using a wxSocketServer object, and a client, which is implemented as a wxSocketClient.

The server binds to the local address, using TCP port number 3000, sets up an event handler to be notified of incoming connection requests (wxSOCKET_CONNECTION events), and sits there, waiting for clients (listening, in socket parlance). For each accepted connection, a new wxSocketBase object is created. These socket objects are independent from the server that created them, so they set up their own event handler, and then request to be notified of wxSOCKET_INPUT (incoming data) or wxSOCKET_LOST (connection closed at the remote end) events. In the sample, the event handler is the same for all connections; to find out which socket the event is addressed to, the GetSocket function is used.

Although it might take some time to get used to the event-oriented system upon which wxSocket is built, the benefits are many. See, for example, that the server application, while being single-threaded (and of course without using fork() or ugly select() loops) can handle an arbitrary number of connections.

The client starts up unconnected, so you can use the Connect... option to specify the address of the server you are going to connect to (the TCP port number is hard-coded as 3000). Once connected, a number of tests are possible. Currently, three tests are implemented. They show how to use the basic IO calls in wxSocketBase, such as Read, Write, ReadMsg and WriteMsg, and how to set up the correct IO flags depending on what you are going to do. See the comments in the code for more information. Note that because both clients and connection objects in the server set up an event handler to catch wxSOCKET_LOST events, each one is immediately notified if the other end closes the connection.

There is also a URL test which shows how to use the wxURL class to fetch data from a given URL.

The sockets sample is work in progress. Some things to do:

ymasuda 平成17年11月19日