php基于协程实现异步的方法分析

更新时间：2020-04-06 03:35:59 作者：startmvc

本文实例讲述了php基于协程实现异步的方法。分享给大家供大家参考，具体如下：github上php

本文实例讲述了php基于协程实现异步的方法。分享给大家供大家参考，具体如下：

github上php的协程大部分是根据这篇文章实现的：http://nikic.github.io/2012/12/22/Cooperative-multitasking-using-coroutines-in-PHP.html。

它们最终的结果都是把回调变成了优雅的顺序执行的代码，但还是阻塞的，不是真正的异步。

比如最热门的：https://github.com/recoilphp/recoil

先安装：


composer require recoil/recoil

执行：


<?php
//recoil.php
include __DIR__ . '/vendor/autoload.php';
use Recoil\React\ReactKernel;
$i = 100000;
ReactKernel::start(task1());
ReactKernel::start(task2());
function task1(){
 global $i;
 echo "wait start" . PHP_EOL;
 while ($i-- > 0) {
 yield;
 }
 echo "wait end" . PHP_EOL;
};
function task2(){
 echo "Hello " . PHP_EOL;
 yield;
 echo "world!" . PHP_EOL;
}

结果：

wait start //等待若干秒 wait end Hello world!

我本来是想让两个任务并行，结果两个任务变成了串行，中间等待的时间什么事情都干不了。React响应式的编程是严格禁止这种等待的，所以我就参照unity3d的协程自己写了个php版本的。上代码：


<?php
//Coroutine.php
//依赖swoole实现的定时器，也可以用其它方法实现定时器
class Coroutine
{
 //可以根据需要更改定时器间隔，单位ms
 const TICK_INTERVAL = 1;
 private $routineList;
 private $tickId = -1;
 public function __construct()
 {
 $this->routineList = [];
 }
 public function start(Generator $routine)
 {
 $task = new Task($routine);
 $this->routineList[] = $task;
 $this->startTick();
 }
 public function stop(Generator $routine)
 {
 foreach ($this->routineList as $k => $task) {
 if($task->getRoutine() == $routine){
 unset($this->routineList[$k]);
 }
 }
 }
 private function startTick()
 {
 swoole_timer_tick(self::TICK_INTERVAL, function($timerId){
 $this->tickId = $timerId;
 $this->run();
 });
 }
 private function stopTick()
 {
 if($this->tickId >= 0) {
 swoole_timer_clear($this->tickId);
 }
 }
 private function run()
 {
 if(empty($this->routineList)){
 $this->stopTick();
 return;
 }
 foreach ($this->routineList as $k => $task) {
 $task->run();
 if($task->isFinished()){
 unset($this->routineList[$k]);
 }
 }
 }
 
}
class Task
{
 protected $stack;
 protected $routine;
 public function __construct(Generator $routine)
 {
 $this->routine = $routine;
 $this->stack = new SplStack();
 }
 /**
 * [run 协程调度]
 * @return [type] [description]
 */
 public function run()
 {
 $routine = &$this->routine;
 try {
 if(!$routine){
 return;
 }
 $value = $routine->current();
 //嵌套的协程
 if ($value instanceof Generator) {
 $this->stack->push($routine);
 $routine = $value;
 return;
 }
 //嵌套的协程返回
 if(!$routine->valid() && !$this->stack->isEmpty()) {
 $routine = $this->stack->pop();
 }
 $routine->next();
 } catch (Exception $e) {
 if ($this->stack->isEmpty()) {
 /*
 throw the exception
 */
 return;
 }
 }
 }
 /**
 * [isFinished 判断该task是否完成]
 * @return boolean [description]
 */
 public function isFinished()
 {
 return $this->stack->isEmpty() && !$this->routine->valid();
 }
 public function getRoutine()
 {
 return $this->routine;
 }
}

测试代码：


<?php
//test.php
 require 'Coroutine.php';
$i = 10000;
$c = new Coroutine();
$c->start(task1());
$c->start(task2());
function task1(){
 global $i;
 echo "wait start" . PHP_EOL;
 while ($i-- > 0) {
 yield;
 }
 echo "wait end" . PHP_EOL;
};
function task2(){
 echo "Hello " . PHP_EOL;
 yield;
 echo "world!" . PHP_EOL;
}

结果：