symfony
diff --git a/‎src/Symfony/Component/HttpKernel/Kernel.php
Copy file name to clipboardExpand all lines: src/Symfony/Component/HttpKernel/Kernel.php
+10-1Lines changed: 10 additions & 1 deletion b/‎src/Symfony/Component/HttpKernel/Kernel.php
Copy file name to clipboardExpand all lines: src/Symfony/Component/HttpKernel/Kernel.php
+10-1Lines changed: 10 additions & 1 deletion
diff --git a/‎src/Symfony/Component/HttpKernel/Tests/KernelTest.php
Copy file name to clipboardExpand all lines: src/Symfony/Component/HttpKernel/Tests/KernelTest.php
+2-1Lines changed: 2 additions & 1 deletion b/‎src/Symfony/Component/HttpKernel/Tests/KernelTest.php
Copy file name to clipboardExpand all lines: src/Symfony/Component/HttpKernel/Tests/KernelTest.php
+2-1Lines changed: 2 additions & 1 deletion
@@ -644,7 +644,16 @@ protected function initializeContainer()
         }
 
         if ($oldContainer && get_class($this->container) !== $oldContainer->name) {
-            (new Filesystem())->remove(dirname($oldContainer->getFileName()));
+            // Because concurrent requests might still be using them,
+            // old container files are not removed immediately,
+            // but on a next dump of the container.
+            $oldContainerDir = dirname($oldContainer->getFileName());
+            foreach (glob(dirname($oldContainerDir).'/*.legacyContainer') as $legacyContainer) {
+                if (@unlink($legacyContainer)) {
+                    (new Filesystem())->remove(substr($legacyContainer, 0, -16));
+                }
+            }
+            touch($oldContainerDir.'.legacyContainer');
         }
 
         if ($this->container->has('cache_warmer')) {
 
@@ -832,7 +832,8 @@ public function testKernelReset()
         $kernel->boot();
 
         $this->assertTrue(get_class($kernel->getContainer()) !== $containerClass);
-        $this->assertFileNotExists($containerFile);
+        $this->assertFileExists($containerFile);
+        $this->assertFileExists(dirname($containerFile).'.legacyContainer');
     }
 
     public function testKernelPass()
Original file line number	Diff line number	Diff line change
`@@ -832,7 +832,8 @@ public function testKernelReset()`
`832`	`832`	`$kernel->boot();`
`833`	`833`
`834`	`834`	`$this->assertTrue(get_class($kernel->getContainer()) !== $containerClass);`
`835`		`- $this->assertFileNotExists($containerFile);`
	`835`	`+ $this->assertFileExists($containerFile);`
	`836`	`+ $this->assertFileExists(dirname($containerFile).'.legacyContainer');`
`836`	`837`	`}`
`837`	`838`
`838`	`839`	`public function testKernelPass()`