The socket_set_nonblock() function sets the
O_NONBLOCK flag on the socket specified by
the socket parameter.
When an operation (e.g. receive, send, connect, accept, ...) is performed on a non-blocking socket, the script not pause its execution until it receives a signal or it can perform the operation. Rather, if the operation would result in a block, the called function will fail.
$socket = socket_create_listen(1223);
This example creates a listening socket on all interfaces on port 1223 and
sets the socket to
socket_accept() will immediately fail unless there is a
pending connection exactly at this moment.