# socket_set_nonblock

(PHP 4 >= 4.1.0, PHP 5, PHP 7)

socket_set_nonblock — Sets nonblocking mode for file descriptor fd

### 说明

socket_set_nonblock ( resource `$socket` ) : bool

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