saveCache does not use lock

[matej21]

• bug report? yes
• version: 3.0.1

saveCache does not use lock and therefore it may fail on this line with following error

E_WARNING: rename(/root/ss/temp/tests/cache/Nette.RobotLoader/b118fb0ce0dea7bbc63b1ce28466196d.php.tmp,/root/ss/temp/tests/cache/Nette.RobotLoader/b118fb0ce0dea7bbc63b1ce28466196d.php): No such file or directory
   
   in /root/ss/vendor/nette/robot-loader/src/RobotLoader/RobotLoader.php(414) rename()
   in /root/ss/vendor/nette/robot-loader/src/RobotLoader/RobotLoader.php(96) Nette\Loaders\RobotLoader->saveCache()
   in [internal function]Nette\Loaders\RobotLoader->tryLoad()
   in [internal function]spl_autoload_call()
....

[dg]

Do you have an idea how to solve it?

[JanTvrdik]

Any of the following should work

1. use lock
2. use @rename(...) + is_file check in case of failure I changed my mind. This won't work.
3. generate random suffix for temporary file

[JanTvrdik]

Unfortunately, it still does not seem to work reliably.

To replicate it's enough to run the following scripts multiple time in parallel after temp directory has been clear.

<?php declare(strict_types = 1);

require __DIR__ . '/../../vendor/autoload.php';

$loader = new Nette\Loaders\RobotLoader;
$loader->setAutoRefresh(true);
$loader->setTempDirectory(__DIR__ . '/../temp');
$loader->addDirectory(__DIR__);
$loader->register();

assert(class_exists(Foo::class) === true);
assert(class_exists(Unknown::class) === false);

Occasionally it fails with error

Warning: rename(.../temp/aed3679f15f72267b5350e48491c0e0e.phpefeebef3986753080eda337bc0681ea6.tmp,.../temp/aed3679f15f72267b5350e48491c0e0e.php): Access is denied. (code: 5) in ...\vendor\nette\robot-loader\src\RobotLoader\RobotLoader.php on line 415

(I tried using random_bytes instead of uniqid but it make no difference)

[dg]

Can you fix it somehow?

[ondrejmirtes]

I'm experiencing this often when implementing parallel analysis in PHPStan. But only on Windows. I think it might be because the system only allows one process to write to a file at a time, so the rename() sometimes isn't successful.

[dg]

It seems that file cannot be deleted / renamed on Windows if it is open. So when PHP is reading it (include $file), renaming will fail.

So I'll use read lock.

[paveljanda]

Sadly, on our projects, robot-loader stopped working in gitlab CI pipeline after updating package to 3.2.2:

Unable to create or acquire shared lock on file '/builds/.......some-package...../tests/integration/../../tests/temp/cache/nette.application/dc419f19af  
   b02aef8183855ed290885d.php

I will provide further details if needed.

[dg]

😐😣😫😭😭😭