Unit test fails with "parallel" extension

[reeperbahnause]

The following PHPUnit test fails if I try to use parallel threads

I'm using php-lock version 2.1 on windows with php version 7.4.6

If I deactivate the $this->mutex->synchronized function by commenting out the function the test is executed without an error.
Does anyone have an idea whats wrong with my test case?

<?php
namespace Squeeze;

use Exception;
use malkusch\lock\mutex\FlockMutex;
use PHPUnit\Framework\TestCase;

class ThreadLockTest extends TestCase
{

    /**
     * @var FlockMutex
     */
    private $mutex;

    /**
     * @var resource
     */
    private $file;

    protected function setUp(): void
    {
        parent::setUp();

        $this->file = __DIR__ . DIRECTORY_SEPARATOR . 'flock';
        $this->mutex = new FlockMutex(fopen($this->file, 'w'), 1);
    }

    protected function tearDown(): void
    {
        unlink($this->file);

        parent::tearDown();
    }

    public function testThreadLock(): void
    {
        $syncFunction = function ($i) {
            try {
                require_once __DIR__ . '/../../../bootstrap/app.php';
                echo $i .' Running ' . PHP_EOL;
                return $this->mutex->synchronized(function () use ($i) : string {
                    sleep(1);
                    return $i .' Finished.' . PHP_EOL;
                });
            } catch (Exception $e) {
                return $e->getMessage() . PHP_EOL;
            }
        };

        $results = array();
        for ($i = 1; $i < 6; $i++) {
            $results[] = \parallel\run($syncFunction, array($i));
        }

        foreach ($results as $item) {
            echo $item->value();
        }
    }
}

[willemstuursma]

Try creating the mutex inside $syncFunction.

[mvorisek]

I copied your repro/test code to CI - b00e0e9.

and hit krakjoe/parallel#337. Let's wait until this MM issue is fixed.

[mvorisek]

I am closing this issue for now as I am not sure how krakjoe/parallel ext should behave. It seems the main memory is not shared with the child thread fully or there is some issue in that ext at least. If there will be some positive progress in krakjoe/parallel#337 we can reopen this this anytime.