socket_set_nonblock

(PHP 4 >= 4.1.0, PHP 5)

socket_set_nonblock — Sets nonblocking mode for file descriptor fd

说明

bool socket_set_nonblock ( resource $socket )

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 will 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.

参数

socket: A valid socket resource created with socket_create() or socket_accept() .

返回值

成功时返回 TRUE ，或者在失败时返回 FALSE 。

范例

Example #1 socket_set_nonblock() 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() will immediately fail unless there is a pending connection exactly at this moment.

参见

socket_set_block() - Sets blocking mode on a socket resource
socket_set_option() - Sets socket options for the socket
stream_set_blocking() - 为资源流设置阻塞或者阻塞模式

用户评论:

[#1] kpobococ at gmail dot com [2009-09-11 07:46:02]

Beware, when using this function within a loop (i.e. a demon with a socket). The socket_accept(), for example, emits a warning each time there is no incoming connection available to be read. My php error log file got huge in a matter of seconds, eventually crashing the server.

Of course, i used the @ before the function to take care of that problem.

[EDITOR: One can (and should) use socket_select to detect a new connection on a socket (it's a "readable" event)]