PHP和并发中静态成员的范围

I have a class that is declared in my application that has a private static member like so:

class SomeClass{
private static myMember =  array(); 

public static getterFunction(){}
public static setterFunction(){}

}

My question / concern is that multiple requests (i'm thinking like a thread in Java) would be able to modify this static member. My understanding of php scope and static members is that they are in the request scope and a new variable is created for each new request and subsequently destroyed after the request has been fulfilled. That said, this would be a difficult thing to test (at least i can't think of an easy way) so i'd rather be safe than sorry.

Is my assessment correct? The PHP docs i've read are pretty crappy in terms of detail so I haven't been able to authoritatively answer yet...

No data, none, is persistent or shared across different instances of PHP scripts unless you explicitly make it so (for example using sessions, databases, files, shared memory). Each PHP instance is its own thing, and each new request causes the webserver to start a separate instance.

So yes, you are correct.

You don't have shared memory by default in PHP. Every single request is being processed in separate process, so they do not know about each other.

I hope I understood your question correctly.

For example:

You have a simple script.php file that sets private field in a class when GET parameter passed:

<?
class A {
  private $x = 1;
  public function setX($x) {$this->x = $x;}
  public function getX() {return $this->x;}
}

$a = new A();
if (!empty($_GET['x'])) {
  $a->setX($_GET['x']);
  sleep(3);
}

echo $a->getX();
?>

You do two requests at once:

GET /script.php?x=5
GET /script.php

Second request will print you "1". Yes, you are correct!