不同于php-fpm每次請求都會(huì)加載一次PHP代碼，常駐型應(yīng)用只會(huì)讀取一次源文件，為了避免每次發(fā)布/調(diào)試代碼都需要手動(dòng)重啟swoft應(yīng)用，swoft提供了自動(dòng)重載代碼的功能。

文件重載管理進(jìn)程

swoft注冊了一個(gè)名為reload的Process,該進(jìn)程會(huì)在系統(tǒng)引導(dǎo)的最后一個(gè)階段，即swoole啟動(dòng)前啟動(dòng)。該P(yáng)rocess會(huì)啟動(dòng)名為reload的Bean

//Swoft\Process\Bootstrap\Process\ReloadProcess.php
/**
 * Relaod process
 *
 * @Process(name="reload", boot=true)
 */
class ReloadProcess implements ProcessInterface
{
    /**
     * @param \Swoft\Process\Process $process
     */
    public function run(SwoftProcess $process)
    {
        $pname = App::$server->getPname();
        $processName = sprintf('%s reload process', $pname);
        $process->name($processName);

        /* @var \Swoft\Process\Bootstrap\Reload $relaod */
        $relaod = App::getBean(Reload::class);
        $relaod->run();
    }
    //.....
}

文件更新監(jiān)聽Bean

//\Swoft\Process\Bootstrap\Reload::class
/**
*  @Bean()
*/
class Reload
{
    //code .....

    /**
     * 啟動(dòng)監(jiān)聽
     */
    public function run()
    {
        $server = App::$server;
        while (true) {
            sleep($this->interval);
            //FileHelper::md5File()負(fù)責(zé)遞歸的計(jì)算文件夾的md5,其實(shí)改名為FileHelper::md5Dir()更合適，因?yàn)樗唤邮芊悄夸浀奈募鳛閰?shù)
            $md5File = FileHelper::md5File($this->watchDir);//$this->watchDir固定為@app別名對應(yīng)的文件夾
            if (strcmp($this->md5File, $md5File) !== 0) {
                echo "Start reloading...\n";
                $server->isRunning();
                //md5和上次不一致就通知swoole重啟服務(wù)
                $server->getServer()->reload();
                echo "Reloaded\n";
            }
            $this->md5File = $md5File;
        }
    }
}

代碼自動(dòng)重載的機(jī)制也很簡單，每間隔幾秒遞歸的計(jì)算@app目錄下所有php文件的哈希值，發(fā)現(xiàn)文件夾的md5和之前的值有差別則通知swoole重啟work進(jìn)程。

Swoole WorkerStart事件

swoole會(huì)通知各個(gè)worker重啟，觸發(fā)swoole事件WorkerStart，具體的回調(diào)事件如下

namespace Swoft\Bootstrap\Server\ServerTrait.php;
    /**
     * OnWorkerStart event callback
     *
     * @param Server $server server
     * @param int $workerId workerId
     * @throws \InvalidArgumentException
     */
    public function onWorkerStart(Server $server, int $workerId)
    {
        // Init Worker and TaskWorker
        $setting = $server->setting;
        $isWorker = false;

        if ($workerId >= $setting['worker_num']) {
            // TaskWorker
            ApplicationContext::setContext(ApplicationContext::TASK);
            ProcessHelper::setProcessTitle($this->serverSetting['pname'] . ' task process');
        } else {
            // Worker
            $isWorker = true;
            ApplicationContext::setContext(ApplicationContext::WORKER);
            ProcessHelper::setProcessTitle($this->serverSetting['pname'] . ' worker process');
        }
        //觸發(fā)一個(gè)Swoft服務(wù)事件```SwooleEvent::ON_START```,其監(jiān)聽者使用@ServerListener(event=SwooleEvent::ON_START)聲明
        $this->fireServerEvent(SwooleEvent::ON_WORKER_START, [$server, $workerId, $isWorker]);
        //主要是重新掃描加載注解和Bean的重載
        $this->beforeWorkerStart($server, $workerId, $isWorker);
    }

Swoft源碼剖析系列目錄：http://m.itdecent.cn/p/2f679e0b4d58