bug #29376 [EventDispatcher] Fix eventListener wrapper loop in TraceableEventDispatcher (jderusse)

nicolas-grekas · nicolas-grekas · commit fb4b75db1b13 · 2018-12-01T09:20:40.000+01:00
This PR was merged into the 3.4 branch. Discussion ---------- [EventDispatcher] Fix eventListener wrapper loop in TraceableEventDispatcher | Q | A | ------------- | --- | Branch? | 3.4 | Bug fix? | yes | New feature? | no | BC breaks? | no | Deprecations? | no | Tests pass? | yes | Fixed tickets | none | License | MIT | Doc PR | na The `TracableEventDispatcher` wrap decorate (in the method `preProcess`) each listeners in a `WrappedListener` before delegating the dispatch to the real dispatcher, then remove the wrapper (in the method `postProcess`. But, if a listener triggers an exception, the `postProcess` method is not called, and the wrapper in not removed. If the same event is triggered a second time, the listeners will be decorated twice, etc, etc.. This is an issue with php-pm where the same event is triggered hundred of times within the same process. This PR moves the `postProcess` in a finally block in order to be called even if an exception in thrown. Commits ------- 3830a9e Fix wrapped loop of event listener
diff --git a/src/Symfony/Component/EventDispatcher/Debug/TraceableEventDispatcher.php b/src/Symfony/Component/EventDispatcher/Debug/TraceableEventDispatcher.php
@@ -132,19 +132,24 @@ public function dispatch($eventName, Event $event = null)
         }
 
         $this->preProcess($eventName);
-        $this->preDispatch($eventName, $event);
-
-        $e = $this->stopwatch->start($eventName, 'section');
-
-        $this->dispatcher->dispatch($eventName, $event);
-
-        if ($e->isStarted()) {
-            $e->stop();
+        try {
+            $this->preDispatch($eventName, $event);
+            try {
+                $e = $this->stopwatch->start($eventName, 'section');
+                try {
+                    $this->dispatcher->dispatch($eventName, $event);
+                } finally {
+                    if ($e->isStarted()) {
+                        $e->stop();
+                    }
+                }
+            } finally {
+                $this->postDispatch($eventName, $event);
+            }
+        } finally {
+            $this->postProcess($eventName);
         }
 
-        $this->postDispatch($eventName, $event);
-        $this->postProcess($eventName);
-
         return $event;
     }
 
