【读源码】workerman中如何实现守护进程[B君笔记][博客]

noscript{position: fixed}【读源码】workerman中如何实现守护进程phpworkerman创建时间：2021-11-12 11:33:46

运行

//不传入协议时，只是一个守护进程
new \Workerman\Worker();
Worker::runAll();

开启守护进程

   protected static function daemonize()
    {
        if (!static::$daemonize || static::$_OS !== \OS_TYPE_LINUX) {
            return;
        }
	// 设置进程权限
        \umask(0);
	// 开启子进程
        $pid = \pcntl_fork();
        if (-1 === $pid) {
            throw new Exception('Fork fail');
        } elseif ($pid > 0) {
	// 退出原来的父进程
            exit(0);
        }
	// 此时当前进程为孤儿进程
        if (-1 === \posix_setsid()) {
            throw new Exception("Setsid fail");
        }
        // Fork again avoid SVR4 system regain the control of terminal.
        $pid = \pcntl_fork();
        if (-1 === $pid) {
            throw new Exception("Fork fail");
        } elseif (0 !== $pid) {
            exit(0);
        }
    }

监听子进程状态

    protected static function monitorWorkersForLinux()
    {
        static::$_status = static::STATUS_RUNNING;
        while (1) {
            // Calls signal handlers for pending signals.
            \pcntl_signal_dispatch();
            // Suspends execution of the current process until a child has exited, or until a signal is delivered
            $status = 0;
            $pid    = \pcntl_wait($status, \WUNTRACED);
            // Calls signal handlers for pending signals again.
            \pcntl_signal_dispatch();
            // If a child has already exited.
            if ($pid > 0) {
                // Find out which worker process exited.
                foreach (static::$_pidMap as $worker_id => $worker_pid_array) {
                    if (isset($worker_pid_array[$pid])) {
                        $worker = static::$_workers[$worker_id];
                        // Exit status.
                        if ($status !== 0) {
                            static::log("worker[" . $worker->name . ":$pid] exit with status $status");
                        }

                        // For Statistics.
                        if (!isset(static::$_globalStatistics['worker_exit_info'][$worker_id][$status])) {
                            static::$_globalStatistics['worker_exit_info'][$worker_id][$status] = 0;
                        }
                        ++static::$_globalStatistics['worker_exit_info'][$worker_id][$status];

                        // Clear process data.
                        unset(static::$_pidMap[$worker_id][$pid]);

                        // Mark id is available.
                        $id  == static::getId($worker_id, $pid);
                        static::$_idMap[$worker_id][$id] = 0;

                        break;
                    }
                }
                // Is still running state then fork a new worker process.
                if (static::$_status !== static::STATUS_SHUTDOWN) {
                    static::forkWorkers();
                    // If reloading continue.
                    if (isset(static::$_pidsToRestart[$pid])) {
                        unset(static::$_pidsToRestart[$pid]);
                        static::reload();
                    }
                }
            }

            // If shutdown state and all child processes exited then master process exit.
            if (static::$_status === static::STATUS_SHUTDOWN && !static::getAllWorkerPids()) {
                static::exitAndClearAll();
            }
        }
    }

注释还是写得很清楚的

如果有子进程退出，返回进程id

$pid = \pcntl_wait($status, \WUNTRACED);

清理对应进程数据

unset(static::$_pidMap[$worker_id][$pid]);

标记为可用

static::$_idMap[$worker_id][$id] = 0;

重启进程

static::forkWorkers();

没重启或者停止，暂停当前进程的执行，继续等子进程退出，放回步骤1

孤儿进程

一个父进程退出，而它的一个或多个子进程还在运行，那么那些子进程将成为孤儿进程。孤儿进程将被init进程(进程号为1)所收养，并由init进程对它们完成状态收集工作。
由于孤儿进程会被init进程给收养，所以孤儿进程不会对系统造成危害