php man page for socket_set_nonblock

SOCKET_SET_NONBLOCK(3)							 1						    SOCKET_SET_NONBLOCK(3)

socket_set_nonblock - Sets nonblocking mode for file descriptor fd

SYNOPSIS
       bool socket_set_nonblock (resource  $socket)

DESCRIPTION
	The socket_set_nonblock(3) 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 will not pause its execu-
       tion 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.

PARAMETERS
	      o $socket
		- A valid socket resource created with socket_create(3) or socket_accept(3).

RETURN VALUES
	Returns TRUE on success or FALSE on failure.

EXAMPLES
       Example #1

	      socket_set_nonblock(3) example

	      <?php
	      $socket = socket_create_listen(1223);
	      socket_set_nonblock($socket);

	      socket_accept($socket);
	      ?>

	       This  example  creates  a  listening socket on all interfaces on port 1223 and sets the socket to O_NONBLOCK mode. socket_accept(3)
	      will immediately fail unless there is a pending connection exactly at this moment.

SEE ALSO
       socket_set_block(3), socket_set_option(3), stream_set_blocking(3).

PHP Documentation Group 												    SOCKET_SET_NONBLOCK(3)