public Class RoundRobinConnectionPool

A ConnectionPool that attempts to provide connections using a round-robin algorithm.

The round-robin behavior is almost impossible to achieve for several reasons:

• the server takes different times to serve different requests; if a request takes a long time to be processed by the server, it would be a performance penalty to stall sending requests waiting for that connection to be available - better skip it and try another connection
• connections may be closed by the client or by the server, so it would be a performance penalty to stall sending requests waiting for a new connection to be opened
• thread scheduling on both client and server may temporarily penalize a connection

Do not expect this class to provide connections in a perfect recurring sequence such as c0, c1, ..., cN-1, c0, c1, ..., cN-1, c0, c1, ... because that is impossible to achieve in a real environment. This class will just attempt a best-effort to provide the connections in a sequential order, but most likely the order will be quasi-random.

Applications using this class should pre-create the connections to ensure that they are already opened when the application starts to requests them, otherwise the first connection that is opened may be used multiple times before the others are opened, resulting in a behavior that is more random-like than more round-robin-like (and that confirms that round-robin behavior is almost impossible to achieve).