Method static variables cannot be changed via reflection

[mvorisek]

Description

The following code:

<?php

class A
{
    public function test()
    {
        static $v = [];
        $v[] = 'x';
    }
}

$r = new \ReflectionMethod(A::class, 'test');
print_r($r->getStaticVariables());

$a = new A();
$a->test();
print_r($r->getStaticVariables());
$a->test();
print_r($r->getStaticVariables());

$r->getStaticVariables()['v'][0] = ['replace_first_x'];
print_r($r->getStaticVariables());

$a->test();
print_r($r->getStaticVariables());

demo: https://3v4l.org/e67fY

Resulted in this output:

...
    [v] => Array
        (
            [0] => x
            [1] => x
            [2] => x
        )
)

But I expected this output instead:

...
    [v] => Array
        (
            [0] => replace_first_x
            [1] => x
            [2] => x
        )
)

The usecase might look absurd, but I have 3rd party lib which stores some objects in static variable which are never released and causes php memory to grow infinitely.

Is there any workaround to my problem (ie. how clear/modify method's static variable from outside the method)?

Also, can this be considerer a bug? I would expect the variable to be returned by a reference, so it can be modified via reflection.

PHP Version

any

Operating System

any

[cmb69]

I would expect the variable to be returned by a reference, so it can be modified via reflection.

ReflectionFunctionAbstract::getStaticVariable() doesn't return the variables, but rather an array mapping from variable names to their values. It may make sense to introduce something like ::setStaticVariableValue().

Is there any workaround to my problem (ie. how clear/modify method's static variable from outside the method)?

Well, there is uopz_set_static(), but it might not be the best idea to use that extension in production. Have you tried to contact the maintainers of the library to improve/fix the issue there?

[mvorisek]

::setStaticVariableValue() would be great!

[krakjoe]

This is just past the remit of normal reflection/introspection: The case for adding this as part of normal reflection doesn't seem obvious, introspection doesn't necessarily include modification, and usually doesn't.

Secondarily and with regard to this specific use case, it looks best to go back to the authors of said library and point out the design flaw.

[bkdotcom]

introspection doesn't necessarily include modification, and usually doesn't.

There's usually, and then there's PHP

• ReflectionProperty::setValue()

(Tracked this "issue" down when attempting to write unit tests for a method with a static var)