Pool 类

(PECL pthreads >= 2.0.0)

简介

Pool 对象是多个 Worker 对象的容器,同时也是它们的控制器。

线程池是对 Worker 功能的高层抽象,包括按照 pthreads 需要的方式来管理应用的功能。

类摘要

Pool {
/* 属性 */
protected $size ;
protected $class ;
protected $workers ;
protected $work ;
protected $ctor ;
protected $last ;
/* 方法 */
public void collect ( Callable $collector )
public Pool __construct ( integer $size , string $class [, array $ctor ] )
public void resize ( integer $size )
public void shutdown ( void )
public integer submit ( Threaded $task )
public integer submitTo ( integer $worker , Threaded $task )
}

属性

size

Pool 对象可容纳的 Worker 对象的最大数量

class

Worker 的类

ctor

构造新的 Worker 对象时所需的参数

workers

指向 Worker 对象的引用

work

指向提交到 Pool 对象中的 Threaded 对象的引用

last

最后使用的 Worker 对象在池中的位置偏移量

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fajan
1 month ago
Example class to demonstrate usage of Pool/Worker mechanism, also to show a few tricks & hints ;)
<?php
class Config extends Threaded{    // shared global object
   
protected $val=0, $val2=0;
    protected function
inc(){++$this->val;}    // protected synchronizes by-object
   
public function inc2(){++$this->val2;}    // no synchronization
}
class
WorkerClass extends Worker{
    protected static
$worker_id_next = -1;
    protected
$worker_id;
    protected
$config;
    public function
__construct($config){
       
$this->worker_id = ++static::$worker_id_next;    // static members are not avalable in thread but are in 'main thread'
       
$this->config = $config;
    }
    public function
run(){
        global
$config;
       
$config = $this->config;    // NOTE: setting by reference WON'T work
       
global $worker_id;
       
$worker_id = $this->worker_id;
        echo
"working context {$worker_id} is created!\n";
       
//$this->say_config();    // globally synchronized function.
   
}
    protected function
say_config(){    // 'protected' is synchronized by-object so WON'T work between multiple instances
       
global $config;        // you can use the shared $config object as synchronization source.
       
$config->synchronized(function() use (&$config){    // NOTE: you can use Closures here, but if you attach a Closure to a Threaded object it will be destroyed as can't be serialized
           
var_dump($config);
        });
    }
}
class
Task extends Stackable{    // Stackable still exists, it's just somehow dissappeared from docs (probably by mistake). See older version's docs for more details.
   
protected $set;
    public function
__construct($set){
       
$this->set = $set;
    }
    public function
run(){
        global
$worker_id;
        echo
"task is running in {$worker_id}!\n";
       
usleep(mt_rand(1,100)*100);
       
$config = $this->getConfig();
       
$val = $config->arr->shift();
       
$config->arr[] = $this->set;
        for (
$i = 0 ; $i < 1000; ++$i){
           
$config->inc();
           
$config->inc2();
        }
    }
    public function
getConfig(){
        global
$config;    // WorkerClass set this on thread's scope, can be reused by Tasks for additional asynch data source. (ie: connection pool or taskqueue to demultiplexer)
       
return $config;
    }
}

$config = new Config;
$config->arr = new \Threaded();
$config->arr->merge(array(1,2,3,4,5,6));
class
PoolClass extends Pool{
    public function
worker_list(){
        if (
$this->workers !== null)
            return
array_keys($this->workers);
        return
null;
    }
}
$pool = new PoolClass(3, 'WorkerClass', [$config] );
$pool->worker_list();
//$pool->submitTo(0,new Task(-10));    // submitTo DOES NOT try to create worker

$spammed_id = -1;
for (
$i = 1; $i <= 100; ++$i){    // add some jobs
   
if ($spammed_id == -1 && ($x = $pool->worker_list())!= null && @$x[2]){
       
$spammed_id = $x[2];
        echo
"spamming worker {$spammed_id} with lots of tasks from now on\n";
    }
    if (
$spammed_id != -1 && ($i % 5) == 0)    // every 5th job is routed to one worker, so it has 20% of the total jobs (with 3 workers it should do ~33%, not it has (33+20)%, so only delegate to worker if you plan to do balancing as well... )
       
$pool->submitTo($spammed_id,new Task(10*$i));   
    else
       
$pool->submit(new Task(10*$i));
}
$pool->shutdown();
var_dump($config); // "val" is exactly 100000, "val2" is probably a bit less
// also: if you disable the spammer, you'll that the order of the "arr" is random.
?>
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