<?php

/**
 * 動態(tài)進程池，類似fpm
 * 動態(tài)新建進程
 * 有初始進程數(shù)，最小進程數(shù)，進程不夠處理時候新建進程，不超過最大進程數(shù)
 */

// 一個進程定時投遞任務

/**
 * 1. tick
 * 2. process及其管道通訊
 * 3. event loop 事件循環(huán)
 */
class processPool
{
  private $pool;

  /**
   * @var swoole_process[] 記錄所有worker的process對象
   */
  private $workers = [];

  /**
   * @var array 記錄worker工作狀態(tài)
   */
  private $used_workers = [];

  /**
   * @var int 最小進程數(shù)
   */
  private $min_woker_num = 5;

  /**
   * @var int 初始進程數(shù)
   */
  private $start_worker_num = 10;

  /**
   * @var int 最大進程數(shù)
   */
  private $max_woker_num = 20;

  /**
   * 進程閑置銷毀秒數(shù)
   * @var int
   */
  private $idle_seconds = 5;

  /**
   * @var int 當前進程數(shù)
   */
  private $curr_num;

  /**
   * 閑置進程時間戳
   * @var array
   */
  private $active_time = [];

  public function __construct()
  {
    $this->pool = new swoole_process(function () {
      // 循環(huán)建立worker進程
      for ($i = 0; $i < $this->start_worker_num; $i++) {
        $this->createWorker();
      }
      echo '初始化進程數(shù)：' . $this->curr_num . PHP_EOL;
      // 每秒定時往閑置的worker的管道中投遞任務
      swoole_timer_tick(1000, function ($timer_id) {
        static $count = 0;
        $count++;
        $need_create = true;
        foreach ($this->used_workers as $pid => $used) {
          if ($used == 0) {
            $need_create = false;
            $this->workers[$pid]->write($count . ' job');
            // 標記使用中
            $this->used_workers[$pid] = 1;
            $this->active_time[$pid] = time();
            break;
          }
        }
        foreach ($this->used_workers as $pid => $used)
          // 如果所有worker隊列都沒有閑置的，則新建一個worker來處理
          if ($need_create && $this->curr_num < $this->max_woker_num) {
            $new_pid = $this->createWorker();
            $this->workers[$new_pid]->write($count . ' job');
            $this->used_workers[$new_pid] = 1;
            $this->active_time[$new_pid] = time();
          }

        // 閑置超過一段時間則銷毀進程
        foreach ($this->active_time as $pid => $timestamp) {
          if ((time() - $timestamp) > $this->idle_seconds && $this->curr_num > $this->min_woker_num) {
            // 銷毀該進程
            if (isset($this->workers[$pid]) && $this->workers[$pid] instanceof swoole_process) {
              $this->workers[$pid]->write('exit');
              unset($this->workers[$pid]);
              $this->curr_num = count($this->workers);
              unset($this->used_workers[$pid]);
              unset($this->active_time[$pid]);
              echo "{$pid} destroyed\n";
              break;
            }
          }
        }

        echo "任務{(diào)$count}/{$this->curr_num}\n";

        if ($count == 20) {
          foreach ($this->workers as $pid => $worker) {
            $worker->write('exit');
          }
          // 關閉定時器
          swoole_timer_clear($timer_id);
          // 退出進程池
          $this->pool->exit(0);
          exit();
        }
      });

    });

    $master_pid = $this->pool->start();
    echo "Master $master_pid start\n";

    while ($ret = swoole_process::wait()) {
      $pid = $ret['pid'];
      echo "process {$pid} existed\n";
    }
  }

  /**
   * 創(chuàng)建一個新進程
   * @return int 新進程的pid
   */
  public function createWorker()
  {
    $worker_process = new swoole_process(function (swoole_process $worker) {
      // 給子進程管道綁定事件
      swoole_event_add($worker->pipe, function ($pipe) use ($worker) {
        $data = trim($worker->read());
        if ($data == 'exit') {
          $worker->exit(0);
          exit();
        }
        echo "{$worker->pid} 正在處理 {$data}\n";
        sleep(5);
        // 返回結(jié)果，表示空閑
        $worker->write("complete");
      });
    });

    $worker_pid = $worker_process->start();

    // 給父進程管道綁定事件
    swoole_event_add($worker_process->pipe, function ($pipe) use ($worker_process) {
      $data = trim($worker_process->read());
      if ($data == 'complete') {
        // 標記為空閑
//        echo "{$worker_process->pid} 空閑了\n";
        $this->used_workers[$worker_process->pid] = 0;
      }
    });

    // 保存process對象
    $this->workers[$worker_pid] = $worker_process;
    // 標記為空閑
    $this->used_workers[$worker_pid] = 0;
    $this->active_time[$worker_pid] = time();
    $this->curr_num = count($this->workers);
    return $worker_pid;
  }

}

new processPool();