PHP下用Swoole實現Actor併發模型

如果的如果發表於2019-06-04
PHP模型

什麼是Actor？

Actor對於PHPer來說，可能會比較陌生，寫過Java的同學會比較熟悉，Java一直都有執行緒的概念（雖然PHP有Pthread,但不普及）,它是一種非共享記憶體的併發模型，每個Actor內的資料獨立存在，Actor之間通過訊息傳遞的形式進行互動排程，且Actor是一種高度抽象化的程式設計模型，非常適合於遊戲、硬體行業。

Swoole協程與信箱

得益於Swoole4.x，我們可以基於Swoole的協程與Channel快速實現一個信箱模式排程。模擬程式碼如下：

use Swoole\Coroutine\Channel;
go(function (){
    //建立十個信箱通道
    $mailBoxes = [];
    for ($i = 1;$i <= 10;$i++){
        $mailBoxes[$i] = new Channel(16);
    }
    //模擬master 郵局排程,隨機像一個信箱投遞訊息
    go(function ()use($mailBoxes){
        while (1){
            \co::sleep(2);
            $key = rand(1,10);
            ($mailBoxes[$key])->push(time());
        }
    });
    //模擬actor 實體消費
    for ($i = 1;$i <= 10;$i++){
        go(function ()use($mailBoxes,$i){
            while (1){
                $msg = ($mailBoxes[$i])->pop();
                echo "Actor {$i} recv msg : {$msg} \n";
            }
        });
    }
});

以上程式碼執行輸出：

php test.php 
Actor 8 recv msg : 1559622691 
Actor 10 recv msg : 1559622693 
Actor 1 recv msg : 1559622695 
Actor 5 recv msg : 1559622697

協程通道每次在POP遇到無資料的時候，都會自動讓出執行權（具體可以去看Swoole協程排程）

Actor庫

基於上面的原理，我們實行了一個多程式分佈的協程Actor庫

composer require easyswoole/actor=2.x-dev
我們依賴dev庫進行測試，生產可以自己依賴stable版本

程式關係

Easyswoole的Actor模型中，存在兩組程式，一組是proxy程式，用來實現Actor對外服務，一組是worker程式，proxy程式與worker程式之間通過unixsock進行通訊，而Actor例項就均勻的分佈worker之中。

樣例程式碼

比如在一個聊天室中，我們可以定義一個房間模型。

namespace EasySwoole\Actor\Test;


use EasySwoole\Actor\AbstractActor;
use EasySwoole\Actor\ActorConfig;

class RoomActor extends AbstractActor
{
    public static function configure(ActorConfig $actorConfig)
    {
        $actorConfig->setActorName('Room');
    }
    public function onStart()
    {
        //每當一個RoomActor實體被建立的時候，都會執行該回撥
        var_dump('room actor '.$this->actorId().' start');
    }
    public function onMessage($msg)
    {
        //每當一個RoomActor實體收到外部訊息的時候，都會執行該回撥當
        var_dump('room actor '.$this->actorId().' onmessage: '.$msg);
        return 'reply at '.time();
    }
    public function onExit($arg)
    { 
        //每當一個RoomActor實體退出的時候，都會執行該回撥
        var_dump('room actor '.$this->actorId().' exit at arg: '.$arg);
        return 'exit at '.time();
    }
    protected function onException(\Throwable $throwable)
    {
        //每當一個RoomActor出現異常的時候，都會執行該回撥
        var_dump($throwable->getMessage());
    }
}

在cli模式下建立一個Actor服務

use EasySwoole\Actor\Actor;
use EasySwoole\Actor\Test\RoomActor;
use EasySwoole\Actor\ProxyProcess;

Actor::getInstance()->register(RoomActor::class);
$list = Actor::getInstance()->generateProcess();

foreach ($list['proxy'] as  $proxy){
    /** @var ProxyProcess $proxy */
    $proxy->getProcess()->start();
}
foreach ($list['worker'] as $actors){
    foreach ($actors as $actorProcess){
        /** @var ProxyProcess $actorProcess */
        $actorProcess->getProcess()->start();
    }
}
while($ret = \Swoole\Process::wait()) {
    echo "PID={$ret['pid']}\n";
}

建立一個cli測試指令碼

use EasySwoole\Actor\Actor;
use EasySwoole\Actor\Test\RoomActor;
Actor::getInstance()->register(RoomActor::class);

go(function (){
    $actorId = RoomActor::client()->create('create arg1');
    var_dump($actorId);
    \co::sleep(3);
    var_dump(RoomActor::client()->send($actorId,'this is msg'));
    \co::sleep(3);
    var_dump(RoomActor::client()->exit($actorId,'this is exit arg'));
    \co::sleep(3);
    RoomActor::client()->create('create arg2');
    \co::sleep(3);
    RoomActor::client()->create('create arg3');
    \co::sleep(3);
    var_dump(RoomActor::client()->sendAll('sendAll msg'));
    \co::sleep(3);
    var_dump(RoomActor::client()->status());
    \co::sleep(3);
    var_dump(RoomActor::client()->exitAll('sendAll exit'));
});

以上程式碼執行結果如下：
服務端

php test.php 
string(40) "room actor 00101000000000000000001 start"
string(57) "room actor 00101000000000000000001 onmessage: this is msg"
string(64) "room actor 00101000000000000000001 exit at arg: this is exit arg"
string(40) "room actor 00101000000000000000002 start"
string(40) "room actor 00103000000000000000001 start"
string(57) "room actor 00101000000000000000002 onmessage: sendAll msg"
string(57) "room actor 00103000000000000000001 onmessage: sendAll msg"
string(60) "room actor 00101000000000000000002 exit at arg: sendAll exit"
string(60) "room actor 00103000000000000000001 exit at arg: sendAll exit"

客戶端

php test2.php 
string(23) "00101000000000000000001"
string(19) "reply at 1559623925"
string(18) "exit at 1559623928"
bool(true)
array(3) {
  [1]=>
  int(1)
  [2]=>
  int(0)
  [3]=>
  int(1)
}
bool(true)

更多細節可以在EasySwoole專案官網得到文件支援 http://easyswoole.com/
喜歡EasySwoole專案的，可以給個star https://github.com/easy-swool...

相關文章