http請(qǐng)求可以直接用workerman或者webman自定義進(jìn)程來做，做成非阻塞http服務(wù)，包括服務(wù)端會(huì)繼續(xù)向客戶端A發(fā)送請(qǐng)求獲取金額這個(gè)過程做成非阻塞的請(qǐng)求。
如果你不會(huì)做，也可以把服務(wù)端會(huì)繼續(xù)向客戶端A發(fā)送請(qǐng)求獲取金額這個(gè)過程設(shè)置個(gè)超時(shí)時(shí)間，比如1秒。

準(zhǔn)備工作

安裝channel

composer require workerman/channel

代碼

start.php

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

// 加載所有Applications/*/start.php，以便啟動(dòng)所有服務(wù)
foreach(glob(__DIR__.'/Applications/*/start*.php') as $start_file)
{
    require_once $start_file;
}

// channel服務(wù)用來多進(jìn)程或者跨服務(wù)器通訊
$channel_server = new Channel\Server('0.0.0.0', 2206);

// 保存設(shè)備到connection的映射
global $connection_maps;
$connection_maps = [];
$http_worker = new Worker('http://0.0.0.0:1234');
$http_worker->onWorkerStart = function () {
    // Channel客戶端連接到Channel服務(wù)端
    Channel\Client::connect('127.0.0.1', 2206);
    Channel\Client::on('get_amount_result', function($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;
    // 通過channel向gatewayWorker咨詢客戶端金額
    Channel\Client::publish('get_amount', [
        'device_id' => $device_id
    ]);
};
$http_worker->onClose = function (\Workerman\Connection\TcpConnection $connection) {
    if (empty($connection->device_id)) {
        return;
    }
    // 刪除$connection_maps對(duì)應(yīng)的連接，避免內(nèi)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]);
    }
};

// 運(yùn)行所有服務(wù)
Worker::runAll();

Events.php

<?php
use \GatewayWorker\Lib\Gateway;
class Events
{
    public static function onWorkerStart($worker)
    {
        // Channel客戶端連接到Channel服務(wù)端
        Channel\Client::connect('127.0.0.1', 2206);
        // 只需要在0號(hào)進(jìn)程上開啟get_amount監(jiān)聽
        if ($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, $message)
   {
       // 忽略客戶端心跳
       if ($message === '{"type":"ping"}') {
           return;
       }
       // 假設(shè)客戶端發(fā)的第一個(gè)消息當(dāng)作device_id
       if (empty($_SESSION['device_id'])) {
           $device_id = trim($message);
           Gateway::bindUid($client_id, $device_id);
           $_SESSION['device_id'] = $device_id;
           return;
       }
       // 客戶端后續(xù)發(fā)的消息當(dāng)作金額
       $amount = $message;
       // 通知http進(jìn)程得到device_id的金額
       Channel\Client::publish('get_amount_result', [
           'device_id' => $_SESSION['device_id'],
           'amount' => $amount
       ]);
   }
}

啟動(dòng)

php start.php start

測(cè)試

瀏覽器打開頁(yè)面 http://127.0.0.1:1234/?device_id=d2

開啟一個(gè)終端，輸入

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代表設(shè)備id
800代表金額

瀏覽器顯示 800

原理

啟動(dòng)一個(gè)channel server作為多進(jìn)程或者跨服務(wù)器通訊組件
businessWorker的Events里onWorkerStart連接channelserver并監(jiān)聽http進(jìn)程發(fā)來的get_amount請(qǐng)求(請(qǐng)求中包含設(shè)備id)
啟動(dòng)一個(gè)httpworker作為http接口，onWorkerStart里連接channelserver并監(jiān)聽get_amount_result結(jié)果(結(jié)果中包含設(shè)備id)
瀏覽器向httpworker發(fā)起請(qǐng)求，httpworker獲得要查詢的設(shè)備id，并將連接保存到connection_maps中，然后通過channel發(fā)布一個(gè)get_amount事件給businessWorke的Events.php
設(shè)備返回金額后在Events里的onMessage里通過channel發(fā)送get_amount_result事件通知http進(jìn)程對(duì)應(yīng)的設(shè)備返回了金額
httpworker獲得金額后查找本地連接里($connection_maps)是否有查詢對(duì)應(yīng)設(shè)備金額的連接，有的話返回金額