That is not a good example of a graceful shutdown. One should close the sending side of the socket and continue to read until the remote end closes its sending connection.
(PHP 4 >= 4.1.0, PHP 5, PHP 7, PHP 8)
socket_shutdown — Shuts down a socket for receiving, sending, or both
$socket
, int $mode
= 2
) : bool
The socket_shutdown() function allows you to stop
incoming, outgoing or all data (the default) from being sent through the
socket
注意:
The associated buffer, or buffers, may or may not be emptied.
socket
A Socket instance created with socket_create().
mode
The value of mode
can be one of the following:
0 |
Shutdown socket reading |
1 |
Shutdown socket writing |
2 |
Shutdown socket reading and writing |
成功时返回 true
, 或者在失败时返回 false
。
版本 | 说明 |
---|---|
8.0.0 |
socket is a Socket instance now;
previously, it was a resource.
|
That is not a good example of a graceful shutdown. One should close the sending side of the socket and continue to read until the remote end closes its sending connection.
Sockets should be first shutdown and then closed.
<?php
// Sample: Closing sockets gracefully
socket_shutdown($sock, 2);
socket_close($sock);
?>
<explain>
In this case, the TCP client is gracefully disconnected from the server
<?php
define('BUF_SIZE',10);
// create for tcp
$sock = socket_create(AF_INET, SOCK_STREAM, getprotobyname('tcp'));
socket_bind($sock, '127.0.0.1',5200);
socket_listen($sock,1024);
$fp = fopen('./socket_shutdown.php','rb');
$clnt_sock = socket_accept($sock);
while(!feof($fp)) {
$str = fread($fp,BUF_SIZE);
socket_write($clnt_sock,$str,BUF_SIZE);
}
$eof = "\n";
socket_write($clnt_sock,$eof,strlen($eof));
//disconnect output stream(断开输入流)
socket_shutdown($clnt_sock,1);
$ret = socket_read($clnt_sock, 100);
printf("Message from client:%s\n",$ret);
socket_close($clnt_sock);
socket_close($sock);
?>
<?php
// for tcp-client
$clnt_sock = socket_create(AF_INET, SOCK_STREAM, getprotobyname('tcp'));
socket_connect($clnt_sock, '127.0.0.1', 5200);
while (($cnt= @socket_read($clnt_sock, 10,PHP_NORMAL_READ)) !==false) {
file_put_contents('./receive.data',$cnt,FILE_APPEND);
}
print "receive file data".PHP_EOL;
socket_write($clnt_sock, "Tank you");
socket_close($clnt_sock);
?>
Shutdown and SOL_TCP:
<?php
$a= socket_create(AF_INET, SOCK_STREAM, SOL_TCP);
socket_shutdown($a, 2)
?>
PHP Warning: socket_shutdown(): unable to shutdown socket [107]: Transport endpoint is not connected
Shutdown and SOL_UDP:
<?php
$a= socket_create(AF_INET, SOCK_STREAM, SOL_UDP);
socket_shutdown($a, 2)
?>
PHP Warning: socket_shutdown(): unable to shutdown socket [107]: Transport endpoint is not connected
Conclusion: if you are not actually connected, shutdown will fails with socket_error = 107, Transport endpoint is not connected. This is true for both TPC and UDP connection (which is suprising, UDP being a connectionless protocol). This is true no matter the value set for the how parameter.