Network Programming with Perl

Nonblocking Connects and Accepts

The remainder of this chapter deals with nonblocking connects and accepts. In addition to read and write operations, sockets can block under two other circumstances: during a call to connect() when the remote host is slow to respond and during calls to accept() while waiting for incoming connections.

connect() may block indefinitely under a variety of conditions, most typically when the remote host is down or a broken router makes it unreachable. In these cases, connect() blocks indefinitely until the error is corrected. Less often, the remote server is overtaxed by incoming requests and is slow to call accept(). In both cases, you can use a nonblocking connect() to limit the time that connect() will block. ...