Fix race condition causing filemtime() warnings during concurrent garbage collection

src/Storage/FileStorage.php

@@ -6,9 +6,11 @@
 
 use Yiisoft\Files\FileHelper;
 
+use function array_filter;
 use function array_slice;
 use function count;
 use function dirname;
+use function file_exists;
 use function filemtime;
 use function glob;
 use function json_decode;
@@ -113,9 +115,17 @@ private function findFilesOrderedByModifiedTime(string $pattern): array
 
         usort(
             $files,
-            static fn (string $a, string $b) => filemtime($b) <=> filemtime($a)
+            static function (string $a, string $b): int {
+                // Use @ to suppress warnings when files are deleted concurrently by another process
+                $mtimeA = @filemtime($a);
+                $mtimeB = @filemtime($b);
+                // filemtime() returns false if file doesn't exist, treat as 0 for sorting
+                return ($mtimeB ?: 0) <=> ($mtimeA ?: 0);
+            }
         );
-        return $files;
+
+        // Filter out files that no longer exist (due to concurrent deletion)
+        return array_filter($files, static fn(string $file): bool => @file_exists($file));
     }
 
     private function encode(mixed $value): string

tests/Unit/Storage/FileStorageTest.php

@@ -51,6 +51,34 @@ public function testClear(): void
         $this->assertDirectoryDoesNotExist($this->path);
     }
 
+    public function testConcurrentDeletion(): void
+    {
+        $storage = $this->getStorage();
+        $storage->setHistorySize(10);
+
+        // Write some data
+        for ($i = 1; $i <= 5; $i++) {
+            $storage->write('test' . $i, [['data' . $i]], [], ['id' => 'test' . $i]);
+            usleep(1000); // 1ms delay to ensure different modification times
+        }
+
+        // Find all summary files
+        $pattern = $this->path . '/**/**/summary.json';
+        $summaryFiles = glob($pattern, GLOB_NOSORT);
+        $this->assertNotEmpty($summaryFiles, 'Should have summary files');
+
+        // Delete one summary file to simulate concurrent deletion during gc
+        if (!empty($summaryFiles)) {
+            unlink($summaryFiles[0]);
+        }
+
+        // This should not produce any warnings even though a file was deleted
+        $summary = $storage->read(StorageInterface::TYPE_SUMMARY);
+
+        // We should get 4 results (5 written - 1 deleted)
+        $this->assertCount(4, $summary);
+    }
+
     public function getStorage(): FileStorage
     {
         return new FileStorage($this->path);