Do not use recursive mkdir() - it's not thread-safe

src/Cache/FileCacheStorage.php

@@ -15,13 +15,18 @@ public function __construct(string $directory)
 		$this->directory = $directory;
 	}
 
+	public function makeRootDir(): void
+	{
+		$this->makeDir($this->directory);
+	}
+
 	private function makeDir(string $directory): void
 	{
 		if (is_dir($directory)) {
 			return;
 		}
 
-		$result = @mkdir($directory, 0777, true);
+		$result = @mkdir($directory, 0777);
 		if ($result === false) {
 			clearstatcache();
 			if (is_dir($directory)) {
@@ -41,7 +46,7 @@ private function makeDir(string $directory): void
 	public function load(string $key, string $variableKey)
 	{
 		return (function (string $key, string $variableKey) {
-			$filePath = $this->getFilePath($key);
+			[,, $filePath] = $this->getFilePaths($key);
 			if (!is_file($filePath)) {
 				return null;
 			}
@@ -66,8 +71,9 @@ public function load(string $key, string $variableKey)
 	 */
 	public function save(string $key, string $variableKey, $data): void
 	{
-		$path = $this->getFilePath($key);
-		$this->makeDir(dirname($path));
+		[$firstDirectory, $secondDirectory, $path] = $this->getFilePaths($key);
+		$this->makeDir($firstDirectory);
+		$this->makeDir($secondDirectory);
 
 		$tmpPath = sprintf('%s/%s.tmp', $this->directory, Random::generate());
 		$tmpSuccess = @file_put_contents(
@@ -92,16 +98,22 @@ public function save(string $key, string $variableKey, $data): void
 		}
 	}
 
-	private function getFilePath(string $key): string
+	/**
+	 * @param string $key
+	 * @return array{string, string, string}
+	 */
+	private function getFilePaths(string $key): array
 	{
 		$keyHash = sha1($key);
-		return sprintf(
-			'%s/%s/%s/%s.php',
-			$this->directory,
-			substr($keyHash, 0, 2),
-			substr($keyHash, 2, 2),
-			$keyHash
-		);
+		$firstDirectory = sprintf('%s/%s', $this->directory, substr($keyHash, 0, 2));
+		$secondDirectory = sprintf('%s/%s', $firstDirectory, substr($keyHash, 2, 2));
+		$filePath = sprintf('%s/%s.php', $secondDirectory, $keyHash);
+
+		return [
+			$firstDirectory,
+			$secondDirectory,
+			$filePath,
+		];
 	}
 
 }

src/Command/CommandHelper.php

@@ -9,6 +9,7 @@
 use Nette\Schema\Processor;
 use Nette\Utils\Strings;
 use Nette\Utils\Validators;
+use PHPStan\Cache\FileCacheStorage;
 use PHPStan\Command\Symfony\SymfonyOutput;
 use PHPStan\Command\Symfony\SymfonyStyle;
 use PHPStan\DependencyInjection\ContainerFactory;
@@ -208,7 +209,7 @@ public static function begin(
 
 		if (!isset($tmpDir)) {
 			$tmpDir = sys_get_temp_dir() . '/phpstan';
-			if (!@mkdir($tmpDir, 0777, true) && !is_dir($tmpDir)) {
+			if (!@mkdir($tmpDir, 0777) && !is_dir($tmpDir)) {
 				$errorOutput->writeLineFormatted(sprintf('Cannot create a temp directory %s', $tmpDir));
 				throw new \PHPStan\Command\InceptionNotSuccessfulException();
 			}
@@ -327,6 +328,11 @@ public static function begin(
 			}
 		}
 
+		$fileCacheStorage = $container->getService('cacheStorage')->makeRootDir();
+		if ($fileCacheStorage instanceof FileCacheStorage) {
+			$fileCacheStorage->makeRootDir();
+		}
+
 		/** @var FileFinder $fileFinder */
 		$fileFinder = $container->getByType(FileFinder::class);
 

src/Testing/TestCase.php

@@ -72,7 +72,7 @@ public static function getContainer(): Container
 
 		if (!isset(self::$containers[$cacheKey])) {
 			$tmpDir = sys_get_temp_dir() . '/phpstan-tests';
-			if (!@mkdir($tmpDir, 0777, true) && !is_dir($tmpDir)) {
+			if (!@mkdir($tmpDir, 0777) && !is_dir($tmpDir)) {
 				self::fail(sprintf('Cannot create temp directory %s', $tmpDir));
 			}
 

tests/bootstrap.php

@@ -1,5 +1,6 @@
 <?php declare(strict_types = 1);
 
+use PHPStan\Cache\FileCacheStorage;
 use PHPStan\Testing\TestCase;
 
 error_reporting(E_ALL);
@@ -21,4 +22,8 @@ public function doFoo($i)
 
 }');
 
-TestCase::getContainer();
+$container = TestCase::getContainer();
+$fileCacheStorage = $container->getService('cacheStorage');
+if ($fileCacheStorage instanceof FileCacheStorage) {
+	$fileCacheStorage->makeRootDir();
+}