使用gateway-worker绑定了client和uid，如何判断uid是否已离线？

http请求可以直接用workerman或者webman自定义进程来做，做成非阻塞http服务，包括服务端会继续向客户端A发送请求获取金额这个过程做成非阻塞的请求。
如果你不会做，也可以把服务端会继续向客户端A发送请求获取金额这个过程设置个超时时间，比如1秒。

准备工作

安装channel

composer require workerman/channel

代码

start.php

<?php
use Workerman\Worker;
define('GLOBAL_START', 1);
require_once __DIR__ . '/vendor/autoload.php';

// 加载所有Applications/*/start.php，以便启动所有服务
foreach(glob(__DIR__.'/Applications/*/start*.php') as $start_file)
{
    require_once $start_file;
}

// channel服务用来多进程或者跨服务器通讯
$channel_server = new Channel\Server('0.0.0.0', 2206);

// 保存设备到connection的映射
global $connection_maps;
$connection_maps = [];
$http_worker = new Worker('http://0.0.0.0:1234');
$http_worker->onWorkerStart = function () {
    // Channel客户端连接到Channel服务端
    Channel\Client::connect('127.0.0.1', 2206);
    Channel\Client::on('get_amount_result', function($data)  {
        global $connection_maps;
        $device_id = $data['device_id'];
        foreach ($connection_maps[$device_id]??[] as $connection) {
            $connection->close($data['amount']);
        }
    });
};
$http_worker->onMessage = function (\Workerman\Connection\TcpConnection $connection, \Workerman\Protocols\Http\Request $request) {
    global $connection_maps;
    $device_id = $request->get('device_id');
    if (!$device_id) {
        $connection->send('not found');
        return;
    }
    $connection->device_id = $device_id;
    $connection_maps[$device_id][$connection->id] = $connection;
    // 通过channel向gatewayWorker咨询客户端金额
    Channel\Client::publish('get_amount', [
        'device_id' => $device_id
    ]);
};
$http_worker->onClose = function (\Workerman\Connection\TcpConnection $connection) {
    if (empty($connection->device_id)) {
        return;
    }
    // 删除$connection_maps对应的连接，避免内存泄漏
    $device_id = $connection->device_id;
    global $connection_maps;
    unset($connection_maps[$device_id][$connection->id]);
    if (empty($connection_maps[$device_id])) {
        unset($connection_maps[$device_id]);
    }
};

// 运行所有服务
Worker::runAll();

Events.php

<?php
use \GatewayWorker\Lib\Gateway;
class Events
{
    public static function onWorkerStart($worker)
    {
        // Channel客户端连接到Channel服务端
        Channel\Client::connect('127.0.0.1', 2206);
        // 只需要在0号进程上开启get_amount监听
        if ($worker->id !== 0) {
            Channel\Client::on('get_amount', function($data)  {
                $device_id = $data['device_id'];
                Gateway::sendToUid($device_id, 'get_amount');
            });
        }
    }
   public static function onMessage($client_id, $message)
   {
       // 忽略客户端心跳
       if ($message === '{"type":"ping"}') {
           return;
       }
       // 假设客户端发的第一个消息当作device_id
       if (empty($_SESSION['device_id'])) {
           $device_id = trim($message);
           Gateway::bindUid($client_id, $device_id);
           $_SESSION['device_id'] = $device_id;
           return;
       }
       // 客户端后续发的消息当作金额
       $amount = $message;
       // 通知http进程得到device_id的金额
       Channel\Client::publish('get_amount_result', [
           'device_id' => $_SESSION['device_id'],
           'amount' => $amount
       ]);
   }
}

启动

php start.php start

测试

浏览器打开页面 http://127.0.0.1:1234/?device_id=d2

开启一个终端，输入

telnet 127.0.0.1 8282
Trying 127.0.0.1...
Connected to 127.0.0.1.
Escape character is '^]'.
d2
800

提示
d2代表设备id
800代表金额

浏览器显示 800

原理

启动一个channel server作为多进程或者跨服务器通讯组件
businessWorker的Events里onWorkerStart连接channelserver并监听http进程发来的get_amount请求(请求中包含设备id)
启动一个httpworker作为http接口，onWorkerStart里连接channelserver并监听get_amount_result结果(结果中包含设备id)
浏览器向httpworker发起请求，httpworker获得要查询的设备id，并将连接保存到connection_maps中，然后通过channel发布一个get_amount事件给businessWorke的Events.php
设备返回金额后在Events里的onMessage里通过channel发送get_amount_result事件通知http进程对应的设备返回了金额
httpworker获得金额后查找本地连接里($connection_maps)是否有查询对应设备金额的连接，有的话返回金额