PHP 套接字 - 接受多个连接

2022-08-30 23:42:47

我正在尝试创建一个简单的客户端/服务器应用程序,因此我正在PHP中试验套接字。

现在我有一个C#中的简单客户端,它可以很好地连接到服务器,但我一次只能将一个客户端连接到此服务器(我在线找到了此代码示例,并对其进行了一些调整以进行测试)。

有趣的是,我发现了同样的问题,基于这里同样的例子:https://stackoverflow.com/questions/10318023/php-socket-connections-cant-handle-multiple-connection

我试图理解它的每个部分,我接近于详细看到它是如何工作的,但由于某种原因,当我连接第二个客户端时,第一个客户端断开连接/崩溃。

任何人都可以给我一些疯狂的想法或指向我应该看的地方吗?

<?php
// Set time limit to indefinite execution
set_time_limit (0);
// Set the ip and port we will listen on
$address = '127.0.0.1';
$port = 9000;
$max_clients = 10;
// Array that will hold client information
$client = array();
// Create a TCP Stream socket
$sock = socket_create(AF_INET, SOCK_STREAM, 0);
// Bind the socket to an address/port
socket_bind($sock, $address, $port) or die('Could not bind to address');
// Start listening for connections
socket_listen($sock);
// Loop continuously
while (true) {
    // Setup clients listen socket for reading
    $read[0] = $sock;
    for ($i = 0; $i < $max_clients; $i++)
    {
        if (isset($client[$i]))
        if ($client[$i]['sock']  != null)
            $read[$i + 1] = $client[$i]['sock'] ;
    }
    // Set up a blocking call to socket_select()
    $ready = socket_select($read, $write = NULL, $except = NULL, $tv_sec = NULL);
    /* if a new connection is being made add it to the client array */
    if (in_array($sock, $read)) {
        for ($i = 0; $i < $max_clients; $i++)
        {
            if (!isset($client[$i])) {
                $client[$i] = array();
                $client[$i]['sock'] = socket_accept($sock);
                echo("Accepting incoming connection...\n");
                break;
            }
            elseif ($i == $max_clients - 1)
                print ("too many clients");
        }
        if (--$ready <= 0)
            continue;
    } // end if in_array

    // If a client is trying to write - handle it now
    for ($i = 0; $i < $max_clients; $i++) // for each client
    {
        if (isset($client[$i]))
        if (in_array($client[$i]['sock'] , $read))
        {
            $input = socket_read($client[$i]['sock'] , 1024);
            if ($input == null) {
                // Zero length string meaning disconnected
                echo("Client disconnected\n");
                unset($client[$i]);
            }
            $n = trim($input);
            if ($n == 'exit') {
                echo("Client requested disconnect\n");
                // requested disconnect
                socket_close($client[$i]['sock']);
            }
            if(substr($n,0,3) == 'say') {
                //broadcast
                echo("Broadcast received\n");
                for ($j = 0; $j < $max_clients; $j++) // for each client
                {
                    if (isset($client[$j]))
                    if ($client[$j]['sock']) {
                        socket_write($client[$j]['sock'], substr($n, 4, strlen($n)-4).chr(0));
                    }
                }
            } elseif ($input) {
                echo("Returning stripped input\n");
                // strip white spaces and write back to user
                $output = ereg_replace("[ \t\n\r]","",$input).chr(0);
                socket_write($client[$i]['sock'],$output);
            }
        } else {
            // Close the socket
            if (isset($client[$i]))
            echo("Client disconnected\n");
            if ($client[$i]['sock'] != null){ 
                socket_close($client[$i]['sock']); 
                unset($client[$i]); 
            }
        }
    }
} // end while
// Close the master sockets
echo("Shutting down\n");
socket_close($sock);
?>

答案 1

这个脚本非常适合我

<?php
    /*! @class      SocketServer
        @author     Navarr Barnier
        @abstract   A Framework for creating a multi-client server using the PHP language.
     */
    class SocketServer
    {
        /*! @var        config
            @abstract   Array - an array of configuration information used by the server.
         */
        protected $config;

        /*! @var        hooks
            @abstract   Array - a dictionary of hooks and the callbacks attached to them.
         */
        protected $hooks;

        /*! @var        master_socket
            @abstract   resource - The master socket used by the server.
         */
        protected $master_socket;

        /*! @var        max_clients
            @abstract   unsigned int - The maximum number of clients allowed to connect.
         */
        public $max_clients = 10;

        /*! @var        max_read
            @abstract   unsigned int - The maximum number of bytes to read from a socket at a single time.
         */
        public $max_read = 1024;

        /*! @var        clients
            @abstract   Array - an array of connected clients.
         */
        public $clients;

        /*! @function   __construct
            @abstract   Creates the socket and starts listening to it.
            @param      string  - IP Address to bind to, NULL for default.
            @param      int - Port to bind to
            @result     void
         */
        public function __construct($bind_ip,$port)
        {
            set_time_limit(0);
            $this->hooks = array();

            $this->config["ip"] = $bind_ip;
            $this->config["port"] = $port;

            $this->master_socket = socket_create(AF_INET, SOCK_STREAM, 0);
            socket_bind($this->master_socket,$this->config["ip"],$this->config["port"]) or die("Issue Binding");
            socket_getsockname($this->master_socket,$bind_ip,$port);
            socket_listen($this->master_socket);
            SocketServer::debug("Listenting for connections on {$bind_ip}:{$port}");
        }

        /*! @function   hook
            @abstract   Adds a function to be called whenever a certain action happens.  Can be extended in your implementation.
            @param      string  - Command
            @param      callback- Function to Call.
            @see        unhook
            @see        trigger_hooks
            @result     void
         */
        public function hook($command,$function)
        {
            $command = strtoupper($command);
            if(!isset($this->hooks[$command])) { $this->hooks[$command] = array(); }
            $k = array_search($function,$this->hooks[$command]);
            if($k === FALSE)
            {
                $this->hooks[$command][] = $function;
            }
        }

        /*! @function   unhook
            @abstract   Deletes a function from the call list for a certain action.  Can be extended in your implementation.
            @param      string  - Command
            @param      callback- Function to Delete from Call List
            @see        hook
            @see        trigger_hooks
            @result     void
         */
        public function unhook($command = NULL,$function)
        {
            $command = strtoupper($command);
            if($command !== NULL)
            {
                $k = array_search($function,$this->hooks[$command]);
                if($k !== FALSE)
                {
                    unset($this->hooks[$command][$k]);
                }
            } else {
                $k = array_search($this->user_funcs,$function);
                if($k !== FALSE)
                {
                    unset($this->user_funcs[$k]);
                }
            }
        }

        /*! @function   loop_once
            @abstract   Runs the class's actions once.
            @discussion Should only be used if you want to run additional checks during server operation.  Otherwise, use infinite_loop()
            @param      void
            @see        infinite_loop
            @result     bool    - True
        */
        public function loop_once()
        {
            // Setup Clients Listen Socket For Reading
            $read[0] = $this->master_socket;
            for($i = 0; $i < $this->max_clients; $i++)
            {
                if(isset($this->clients[$i]))
                {
                    $read[$i + 1] = $this->clients[$i]->socket;
                }
            }

            // Set up a blocking call to socket_select
            if(socket_select($read,$write = NULL, $except = NULL, $tv_sec = 5) < 1)
            {
            //  SocketServer::debug("Problem blocking socket_select?");
                return true;
            }

            // Handle new Connections
            if(in_array($this->master_socket, $read))
            {
                for($i = 0; $i < $this->max_clients; $i++)
                {
                    if(empty($this->clients[$i]))
                    {
                        $temp_sock = $this->master_socket;
                        $this->clients[$i] = new SocketServerClient($this->master_socket,$i);
                        $this->trigger_hooks("CONNECT",$this->clients[$i],"");
                        break;
                    }
                    elseif($i == ($this->max_clients-1))
                    {
                        SocketServer::debug("Too many clients... :( ");
                    }
                }

            }

            // Handle Input
            for($i = 0; $i < $this->max_clients; $i++) // for each client
            {
                if(isset($this->clients[$i]))
                {
                    if(in_array($this->clients[$i]->socket, $read))
                    {
                        $input = socket_read($this->clients[$i]->socket, $this->max_read);
                        if($input == null)
                        {
                            $this->disconnect($i);
                        }
                        else
                        {
                            SocketServer::debug("{$i}@{$this->clients[$i]->ip} --> {$input}");
                            $this->trigger_hooks("INPUT",$this->clients[$i],$input);
                        }
                    }
                }
            }
            return true;
        }

        /*! @function   disconnect
            @abstract   Disconnects a client from the server.
            @param      int - Index of the client to disconnect.
            @param      string  - Message to send to the hooks
            @result     void
        */
        public function disconnect($client_index,$message = "")
        {
            $i = $client_index;
            SocketServer::debug("Client {$i} from {$this->clients[$i]->ip} Disconnecting");
            $this->trigger_hooks("DISCONNECT",$this->clients[$i],$message);
            $this->clients[$i]->destroy();
            unset($this->clients[$i]);          
        }

        /*! @function   trigger_hooks
            @abstract   Triggers Hooks for a certain command.
            @param      string  - Command who's hooks you want to trigger.
            @param      object  - The client who activated this command.
            @param      string  - The input from the client, or a message to be sent to the hooks.
            @result     void
        */
        public function trigger_hooks($command,&$client,$input)
        {
            if(isset($this->hooks[$command]))
            {
                foreach($this->hooks[$command] as $function)
                {
                    SocketServer::debug("Triggering Hook '{$function}' for '{$command}'");
                    $continue = call_user_func($function,&$this,&$client,$input);
                    if($continue === FALSE) { break; }
                }
            }
        }

        /*! @function   infinite_loop
            @abstract   Runs the server code until the server is shut down.
            @see        loop_once
            @param      void
            @result     void
        */
        public function infinite_loop()
        {
            $test = true;
            do
            {
                $test = $this->loop_once();
            }
            while($test);
        }

        /*! @function   debug
            @static
            @abstract   Outputs Text directly.
            @discussion Yeah, should probably make a way to turn this off.
            @param      string  - Text to Output
            @result     void
        */
        public static function debug($text)
        {
            echo("{$text}\r\n");
        }

        /*! @function   socket_write_smart
            @static
            @abstract   Writes data to the socket, including the length of the data, and ends it with a CRLF unless specified.
            @discussion It is perfectly valid for socket_write_smart to return zero which means no bytes have been written. Be sure to use the === operator to check for FALSE in case of an error. 
            @param      resource- Socket Instance
            @param      string  - Data to write to the socket.
            @param      string  - Data to end the line with.  Specify a "" if you don't want a line end sent.
            @result     mixed   - Returns the number of bytes successfully written to the socket or FALSE on failure. The error code can be retrieved with socket_last_error(). This code may be passed to socket_strerror() to get a textual explanation of the error.
        */
        public static function socket_write_smart(&$sock,$string,$crlf = "\r\n")
        {
            SocketServer::debug("<-- {$string}");
            if($crlf) { $string = "{$string}{$crlf}"; }
            return socket_write($sock,$string,strlen($string));
        }

        /*! @function   __get
            @abstract   Magic Method used for allowing the reading of protected variables.
            @discussion You never need to use this method, simply calling $server->variable works because of this method's existence.
            @param      string  - Variable to retrieve
            @result     mixed   - Returns the reference to the variable called.
        */
        function &__get($name)
        {
            return $this->{$name};
        }
    }

    /*! @class      SocketServerClient
        @author     Navarr Barnier
        @abstract   A Client Instance for use with SocketServer
     */
    class SocketServerClient
    {
        /*! @var        socket
            @abstract   resource - The client's socket resource, for sending and receiving data with.
         */
        protected $socket;

        /*! @var        ip
            @abstract   string - The client's IP address, as seen by the server.
         */
        protected $ip;

        /*! @var        hostname
            @abstract   string - The client's hostname, as seen by the server.
            @discussion This variable is only set after calling lookup_hostname, as hostname lookups can take up a decent amount of time.
            @see        lookup_hostname
         */
        protected $hostname;

        /*! @var        server_clients_index
            @abstract   int - The index of this client in the SocketServer's client array.
         */
        protected $server_clients_index;

        /*! @function   __construct
            @param      resource- The resource of the socket the client is connecting by, generally the master socket.
            @param      int - The Index in the Server's client array.
            @result     void
         */
        public function __construct(&$socket,$i)
        {
            $this->server_clients_index = $i;
            $this->socket = socket_accept($socket) or die("Failed to Accept");
            SocketServer::debug("New Client Connected");
            socket_getpeername($this->socket,$ip);
            $this->ip = $ip;
        }

        /*! @function   lookup_hostname
            @abstract   Searches for the user's hostname and stores the result to hostname.
            @see        hostname
            @param      void
            @result     string  - The hostname on success or the IP address on failure.
         */
        public function lookup_hostname()
        {
            $this->hostname = gethostbyaddr($this->ip);
            return $this->hostname;
        }

        /*! @function   destroy
            @abstract   Closes the socket.  Thats pretty much it.
            @param      void
            @result     void
         */
        public function destroy()
        {
            socket_close($this->socket);
        }

        function &__get($name)
        {
            return $this->{$name};
        }

        function __isset($name)
        {
            return isset($this->{$name});
        }
    }

Github 上的源代码


答案 2

目前这里最重要的答案是错误的,你不需要多个线程来处理多个客户端。您可以使用非阻塞 I/O 和 / 来处理来自可操作客户端的消息。我建议使用函数而不是.stream_selectsocket_selectstream_socket_*socket_*

虽然非阻塞 I/O 工作正常,但您无法使用涉及阻塞 I/O 进行任何函数调用,否则阻塞 I/O 会阻塞整个进程,并且所有客户端都会挂起,而不仅仅是一个。

这意味着所有I / O都必须是非阻塞的或保证非常快的(这并不完美,但可能是可以接受的)。因为不仅你的套接字需要使用,而且你需要在所有开放流上选择,所以我推荐一个库,提供注册读取和写入观察程序,一旦流变得可读/可写,就会执行这些观察程序。stream_select

有多种这样的框架可用,最常见的是ReactPHPAmp。底层事件循环非常相似,但Amp在该侧提供了更多功能。

两者之间的主要区别在于 API 的方法。虽然 ReactPHP 在任何地方都使用回调,但 Amp 试图通过使用协程并针对此类用法优化其 API 来避免回调。

Amp 的“入门”指南基本上就是关于这个主题的。您可以在此处阅读完整指南。我将在下面包括一个工作示例。

<?php

require __DIR__ . "/vendor/autoload.php";

// Non-blocking server implementation based on amphp/socket.

use Amp\Loop;
use Amp\Socket\ServerSocket;
use function Amp\asyncCall;

Loop::run(function () {
    $uri = "tcp://127.0.0.1:1337";

    $clientHandler = function (ServerSocket $socket) {
        while (null !== $chunk = yield $socket->read()) {
            yield $socket->write($chunk);
        }
    };

    $server = Amp\Socket\listen($uri);

    while ($socket = yield $server->accept()) {
        asyncCall($clientHandler, $socket);
    }
});

Loop::run()运行事件循环并监视计时器事件、信号和可操作流,这些事件、信号和可操作流可以使用方法注册。服务器套接字是使用 创建的。 返回 可用于等待新客户端连接的 a。一旦客户端被接受,它就会执行一个协程,从客户端读取并将相同的数据回显回它。有关更多详细信息,请参阅 Amp 的文档。Loop::on*()Amp\Socket\listen()Server::accept()Promise


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