Cond 类

(PECL pthreads < 3.0.0)

简介

Warning

pthreads v3 中已经将 Cond 类移除。

Cond 类中的静态方法可以用来直接访问 Posix 的条件变量。

类摘要

Cond {
/* 方法 */
final public static broadcast ( int $condition ) : bool
final public static create ( void ) : int
final public static destroy ( int $condition ) : bool
final public static signal ( int $condition ) : bool
final public static wait ( int $condition , int $mutex [, int $timeout ] ) : bool
}

Table of Contents

User Contributed Notes

312036773 at qq dot com 20-Dec-2015 06:39
public function run(){
        Mutex::lock($this->mutex);
        if($this->account->getBalance() >= drawCost){
            usleep ( 500 );
            $this->account->draw(drawCost);
            echo \Thread::getCurrentThreadId () . "__get__" . drawCost . ",The current Balance is:{$this->account->getBalance()}<br/>";
            Cond::broadcast($this->cond);
        }
        else {
            echo \Thread::getCurrentThreadId () . "__get fail__,the current Balance is:{$this->account->getBalance()}<br/>";

//Use Wait Can be not Running......Why ???

            Cond::wait($this->cond,$this->mutex);
        }
        Mutex::unlock($this->mutex);
  }
jan 25-May-2013 01:11
As Cond (nor Mutex) is good for queuing tasks, and arrays/objects stored a "serialized" (can't use it as excepted for signals outside the run()) here is a simple task queue trait:
<?php
define('T',1000000);
trait TaskQueue{
    private $queue_len = 0;
    private $queue_pointer = 0;
    private $queue_curr = 0;
    protected function queueInit(){$this->queue_len = 0; $this->queue_pointer = 0; $this->queue_curr = 0;}
    protected function getNextQueued(){
        if ($this->queue_len == 0) return null;
        $p = $this->queue_curr;
        $x = 0;
        $ret = [];
        do{
            $key = "queue_func_{$p}";
            if ($this->$key){
                $ret['func'] = $this->$key;
                unset($this->$key);
                $key = "queue_params_{$p}";
                $prs = $this->$key;
                unset($this->$key);
                $ret['params'] = [];
                for ($i = 0; $i < $prs; $i++){
                    $key = "queue_param_{$p}_{$i}";
                    $ret['params'][] =  $this->$key;
                    unset($this->$key);
                }
                $this->queue_len--;
                $this->queue_curr++;
                return $ret;
            }
            else $p++;
            if ($x++ > 1000){   // the queue is corrupt
                echo "\n\t\t task queue is corrupt for ".get_called_class()."\n";
                $this->queue_len = 0;
                $this->queue_pointer = 0;
                return null;
            }
        }while(isset($this->$key));
        return null;

    }
    protected function addToQueue($func,$params = []){
        if (!is_array($params) || !@method_exists($this,$func)) return false;
        $p = $this->queue_pointer;
        $key = "queue_func_{$p}";
        $this->$key = $func;
        $key = "queue_params_{$p}";
        $this->$key = count($params);
        $i = 0;
        foreach ($params as $pa){
            $key = "queue_param_{$p}_{$i}";
            $this->$key = $pa;
            $i++;
        }
        $this->queue_pointer++;
        $this->queue_len++;
        return true;
    }
}

class A extends Thread{
    use TaskQueue;
    private $sig_term;
    public function __construct(){
        $this->cond = Cond::create();
        $this->sig_term = false;
        $this->queueInit(); // threads don't like default parameters
        $this->start();
    }

    public function run(){
        while(!$this->sig_term){
            while(($qi = $this->getNextQueued())){
                call_user_func_array([$this,$qi['func']],$qi['params']);
            }
            echo "now doing MAIN -- ";
            usleep(1*T);
            echo "finished MAIN\n";
        }
        Mutex::destroy($m);
    }

    private function reallyDoA($a){
        echo "doing A: {$a} -- ";
        usleep(0.7*T);
        echo "finished A\n";

    }
    public function doA($param1){
        $this->addToQueue('reallyDoA',[$param1]);
    }
    private function reallyDoB($a,$b){
        echo "doing B: {$a},{$b} -- ";
        usleep(0.1*T);
        echo "finished B\n";

    }
    public function doB($param1, $param2){
        $this->addToQueue('reallyDoB',[$param1,$param2]);
    }
    public function term(){$this->sig_term = true;}
}

$a = new A();
usleep(1.2*T);
$a->doA(2);
$a->doA(3);
$a->doB("now b","something");
usleep(5.4*T);
$a->doA(5);
$a->doA(7);

usleep(3*T);
$a->term();
$a->join();
?>
very useful if you need syncronization from an outside event (ie: async socket read/write - your run() takes care of reading with timeout / signalig on_packet events, but writing may occur at any time (ie async heartbeeting) and fwrite($sock) while stream_select($sock) is waiting for timeout causes segfaults...)