PHP线程应如何存储其数据？

所以我一直在网上搜索和阅读有关PHP pthreads3以及它们应该如何存储数据的信息. (或更确切地说,它们不是)
在我看来,线程正确存储其数据的唯一方法是创建一个新的Threaded对象并将其发送给线程.然后,线程可以使用此Threaded对象存储几乎所有数据.

我的问题,也是掌握PHP线程的最大问题：
是否可以在需要时让线程创建自己的存储对象？
我不知道如何或为什么,因为我在此找到的所有答案都含糊不清,详尽而令人困惑,“也许,但没有”,主要与性能差和内存问题/安全性有关.
这似乎应该可行,无论如何：

class someFantasticThread extends Thread {
    public $someData;

    function run(){
        while(true){
            //Create a fresh storage for the new data this iteration
            $this->someData = new SomeCoolStorage(); // Can this work somehow without all the issues?
            $this->someData[] = 'amazingdata'; // Do something amazing and store the new results in $someData
            $this->someData[] = new SomeCoolStorage(); // This would also be desireable, if it can somehow be done
            //don't mind the obvious loop issues. Imagine this is a well formed loop
        }
    }
}

class SomeCoolStorage extends Threaded{}

// Start the thread
$threadObj = new someFantasticThread();
$threadObj->start();
while(true){
    // at some point, retrieve the data and do something useful with the contained results
    // doSomethingAwesome($threadObj->someData);
}

解决方法:

It seems to me that the only way for a thread to store its data properly is to create a new Threaded object and send it to the thread.

是的,这是一种方法.

Is it possible to have the thread create its own storage objects when it wants?

是的,但前提是您必须在该线程(或它可能产生的任何子线程)中对其进行操作.

在PHP中使用线程时要理解的基本知识之一是,Threaded类的对象与创建它们的上下文相关.这意味着,如果您在主线程中创建一个Threaded对象,将该对象传递给一个生成的子线程,然后加入该生成的子线程,那么您可以继续正常使用该Threaded对象.

示例1(构造函数注入)：

<?php

$store = new Threaded(); // created in the main thread

$thread = new class($store) extends Thread {
    public $store;

    public function __construct(Threaded $store)
    {
        $this->store = $store;
    }

    public function run()
    {
        $this->store[] = 1;
        $this->store[] = 2;
    }
};

$thread->start() && $thread->join();

print_r($store); // continue using it in the main thread

这将输出：

Threaded Object
(
    [0] => 1
    [1] => 2
)

在上面的示例中,我们还可以在构造函数内部创建Threaded对象,然后执行var_dump($thread-> store);在脚本末尾.之所以可行,是因为Threaded对象仍在需要它的最外层范围中创建,因此它并不与可能已经被破坏的任何子线程的范围相关. (PHP中唯一在单独的线程中执行的线程的一部分是Thread :: run方法.)

与以上示例类似,我们也可以使用setter注入. (不过,同样,只要在将使用Threaded对象的最外部作用域中的线程调用setter即可.)

许多不熟悉PHP线程开发的开发人员似乎遇到的问题是,他们从新线程内部创建Threaded对象,然后期望在加入同一线程时能够使用该Threaded对象.

例：

<?php

$thread = new class() extends Thread {
    public $store;

    public function run()
    {
        $this->store = new Threaded(); // created inside of the child thread
        $this->store[] = 1;
        $this->store[] = 2;
    }
};

$thread->start() && $thread->join();

print_r($thread->store); // attempt to use it in the outer context (the main thread)

这将输出：

RuntimeException: pthreads detected an attempt to connect to an object which has already been destroyed in %s:%d

这是因为加入生成的子线程时,$thread-> store中的Threaded对象已被破坏.这个问题也可能更加微妙.例如,在Threaded对象内部创建新数组将自动将其强制转换为Volatile对象(也是Threaded对象).

这意味着以下示例也不起作用：

<?php

$thread = new class() extends Thread {
    public $store;

    public function run()
    {
        $this->store = [];
        $this->store[] = 1;
        $this->store[] = 2;
    }
};

$thread->start() && $thread->join();

print_r($thread->store);

输出：

RuntimeException: pthreads detected an attempt to connect to an object which has already been destroyed in %s:%d

回到示例代码,您的工作绝对没问题,但前提是您不尝试在该子线程之外使用$this-> someData.

标签：php,multithreading,pthreads,php-7-1
来源： https://codeday.me/bug/20191011/1890166.html