PHP: Hypertext Preprocessor (original) (raw)
socket_set_nonblock
(PHP 4 >= 4.1.0, PHP 5, PHP 7, PHP 8)
socket_set_nonblock — Sets nonblocking mode for file descriptor fd
Description
socket_set_nonblock(Socket $socket): bool
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.
Return Values
Returns [true](reserved.constants.php#constant.true) on success or [false](reserved.constants.php#constant.false) on failure.
Changelog
| Version | Description |
|---|---|
| 8.0.0 | socket is a Socket instance now; previously, it was a resource. |
Examples
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](dio.constants.php#constant.o-nonblock) mode. socket_accept() will immediately fail unless there is a pending connection exactly at this moment.
See Also
- socket_set_block() - Sets blocking mode on a socket
- socket_set_option() - Sets socket options for the socket
- stream_set_blocking() - Set blocking/non-blocking mode on a stream
Found A Problem?
15 years ago
`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)]
`