問(wèn)題描述

在例子中，onMessage是一個(gè)協(xié)程，從這個(gè)協(xié)程進(jìn)入新的協(xié)Coroutine::create，這個(gè)新的協(xié)程結(jié)束后返回onMessage協(xié)程，然后通過(guò)context獲取user_info是成功，這樣做法與user_info保存到一個(gè)變量$user_info中，然后進(jìn)入新協(xié)程，協(xié)程結(jié)束后返回onMessage協(xié)程，照樣拿到$user_info的值，那context方式跟用變量保存方式好像沒(méi)什么區(qū)別？有沒(méi)有人知道context主要用在什么樣的場(chǎng)景呢？

<?php

use Workerman\Connection\TcpConnection;
use Workerman\Coroutine;
use Workerman\Coroutine\Context;
use Workerman\Events\Swoole;
use Workerman\Protocols\Http\Request;
use Workerman\Worker;
require_once __DIR__ . '/vendor/autoload.php';

$worker = new Worker('http://0.0.0.0:8001');

$worker->eventLoop = Swoole::class; // Or Swow::class or Fiber::class

$worker->onMessage = function (TcpConnection $connection, Request $request) {
    // 在當(dāng)前協(xié)程設(shè)置context數(shù)據(jù)
    Context::set('user_info', ['id' => 1, 'name' => 'name']);
    // 新建協(xié)程
    Coroutine::create(function () use ($connection) {
        // 協(xié)程間context數(shù)據(jù)是隔離的，所以新協(xié)程里獲取的是null
        $userInfo = Context::get('user_info');
        var_dump($userInfo); // 輸出null
    });
    // 獲取當(dāng)前協(xié)程的context數(shù)據(jù)
    $userInfo = Context::get('user_info'); // 得到['id' => 1, 'name' => 'name']
    $connection->send(json_encode($userInfo));
};
$worker->onClose = function(TcpConnection $connection)use($worker,&$all_golbal_count)
{
    echo json_encode(Context::get('user_info'))."\n";
    echo connection closed."\n";
};
Worker::runAll();
?>