協(xié)程編程注意事項(xiàng)

use Swoole\Coroutine;class Context{   protected static $pool = []; //進(jìn)程創(chuàng)建后此靜態(tài)變量就會(huì)存在，但只會(huì)根據(jù)對(duì)應(yīng)的id去覆蓋對(duì)應(yīng)協(xié)程下的數(shù)據(jù)     // 基于協(xié)程 `ID` 獲取數(shù)據(jù)    static function get($key){        $cid = Coroutine::getCid();        if ($cid < 0)        {            return null;        }        if(isset(self::$pool[$cid][$key])){            return self::$pool[$cid][$key];        }        return null;    }     // 基于協(xié)程 `ID` 寫入數(shù)據(jù)    static function put($key, $item){        $cid = Coroutine::getCid();        if ($cid > 0)        {            self::$pool[$cid][$key] = $item;        }     }     // 基于協(xié)程 `ID` 刪除數(shù)據(jù)    static function delete($key = null){        $cid = Coroutine::getCid();        if ($cid > 0)        {            if($key){                unset(self::$pool[$cid][$key]);            }else{                unset(self::$pool[$cid]);            }        }    }}

$pool = new RedisPool();$server = new Swoole\Http\Server('127.0.0.1', 9501);$server->set([    // 如開(kāi)啟異步安全重啟, 需要在workerExit釋放連接池資源    'reload_async' => true]);$server->on('start', function (swoole_http_server $server) {    var_dump($server->master_pid);});$server->on('workerExit', function (swoole_http_server $server) use ($pool) {    $pool->destruct();});$server->on('request', function (swoole_http_request $req, swoole_http_response $resp) use ($pool) {    //從連接池中獲取一個(gè)Redis協(xié)程客戶端    $redis = $pool->get();    //連接失敗    if ($redis === false) {        $resp->end("ERROR");        return;    }    $result = $redis->hgetall('key');    $resp->end(var_export($result, true));    //釋放客戶端，其他協(xié)程可復(fù)用此對(duì)象    $pool->put($redis);});$server->start();
class RedisPool{    protected $available = true;    protected $pool;
    public function __construct(){        $this->pool = new SplQueue;    }
    public function put($redis){        $this->pool->push($redis);    }
    /**     * @return bool|mixed|\Swoole\Coroutine\Redis     */    public function get(){        //有空閑連接且連接池處于可用狀態(tài)        if ($this->available && count($this->pool) > 0) {            return $this->pool->pop();        }
        //無(wú)空閑連接，創(chuàng)建新連接        $redis = new Swoole\Coroutine\Redis();        $res = $redis->connect('127.0.0.1', 6379);        if ($res == false) {            return false;        } else {            return $redis;        }    }
    public function destruct(){        // 連接池銷毀, 置不可用狀態(tài), 防止新的客戶端進(jìn)入常駐連接池, 導(dǎo)致服務(wù)器無(wú)法平滑退出        $this->available = false;        while (!$this->pool->isEmpty()) {            $this->pool->pop();        }    }}

錯(cuò)誤：try {    Swoole\Coroutine::create(function () {        throw new \RuntimeException(__FILE__, __LINE__);    });}catch (\Throwable $e) {    echo $e;}#try/catch和throw在不同的協(xié)程中，協(xié)程內(nèi)無(wú)法捕獲到此異常。當(dāng)協(xié)程退出時(shí)，發(fā)現(xiàn)有未捕獲的異常，將引起致命錯(cuò)誤。
正解：function test() {    throw new \RuntimeException(__FILE__, __LINE__);}Swoole\Coroutine::create(function () {    try {        test();    }    catch (\Throwable $e) {        echo $e;    }});