您链接的代码是很久以前编写的，当时我对非阻塞 I/O 的许多方面了解有限。
这确实需要一个事件循环，其中有很多实现，但对于这个示例，我将使用@rdlowrey 的Alert 库，因为它是一个极简代码，应该相当容易理解。您也可以在React 处进行循环，这是更高级别并提供更多功能。
请注意，以下示例需要 PHP 5.4+
<?php
// Array of addresses to test
$addresses = [
'192.168.5.150',
'192.168.5.152',
'google.com', // Important note: DNS is resolved synchronously here.
'192.168.5.155', // this can seriously slow down the process as it can block
'192.168.5.20', // for a few seconds, async DNS resolution is non-trivial
'192.168.40.40', // though
];
// The TCP port to test
$port = 80;
// The length of time in seconds to allow host to respond
$timeout = 5;
// This will hold the results
$lookups = [];
// Create a reactor
$reactor = (new \Alert\ReactorFactory)->select();
$count = count($addresses);
$completedCount = 0;
$onComplete = function($address, $result)
use(&$lookups, &$completedCount, $count, $reactor) {
// Cancel the watchers for this address
$reactor->cancel($lookups[$address]['failWatcher']);
$reactor->cancel($lookups[$address]['writeWatcher']);
$reactor->cancel($lookups[$address]['readWatcher']);
// Store the result
$lookups[$address] = $result;
// If there's nothing left to do, stop the reactor
if (++$completedCount == $count) {
$reactor->stop();
}
};
foreach ($addresses as $address) {
// Normalise the address to lower-case, as it will be used as an array key
$address = strtolower($address);
if (!isset($lookups[$address])) {
// Create a socket to connect asynchronously
$sockAddr = "tcp://{$address}:{$port}";
$flags = STREAM_CLIENT_ASYNC_CONNECT;
$socket = stream_socket_client($sockAddr, $errNo, $errStr, 0, $flags);
stream_set_blocking($socket, 0);
// Set up a timeout to watch for failed connections
$failWatcher = function() use($address, $onComplete, $timeout) {
echo "{$address} connect failed: Connect timed out\n";
$onComplete($address, false);
};
$failWatcherId = $reactor->once($failWatcher, $timeout);
// Watch for the stream becoming writable (connection success)
$writeWatcher = function() use($address, $onComplete) {
echo "{$address} connected successfully\n";
$onComplete($address, true);
};
$writeWatcherId = $reactor->onWritable($socket, $writeWatcher);
// Watch for the stream becoming readable (success or explicit fail)
$readWatcher = function() use($address, $onComplete, $socket) {
if ('' === $data = fread($socket, 1024)) {
echo "{$address} connect failed: Server refused connection\n";
$onComplete($address, false);
} else if ($data === false) {
echo "{$address} connect failed: Stream read error\n";
$onComplete($address, false);
} else {
echo "{$address} connected successfully\n";
$onComplete($address, true);
}
};
$readWatcherId = $reactor->onReadable($socket, $readWatcher);
// Store the watcher IDs so they can be destroyed later
$lookups[$address] = [
'failWatcher' => $failWatcherId,
'writeWatcher' => $writeWatcherId,
'readWatcher' => $readWatcherId,
];
}
}
// Set everything going
$reactor->run();
// $lookups is now an array of booleans indicating whether the address resulted
// in a successful connection