Don't access a message after it has been enqueued. It may be deleted

runtime/vm/isolate.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/isolate.h"
 
 #include "include/dart_api.h"
 #include "platform/assert.h"
 #include "vm/bigint_store.h"
 #include "vm/code_index_table.h"
@@ skipping 82 matching lines @@
     if (source_isolate) {
       source_name = source_isolate->name();
     }
     OS::Print("[>] Posting message:\n"
               "\tsource:     %s\n"
               "\treply_port: %lld\n"
               "\tdest:       %s\n"
               "\tdest_port:  %lld\n",
               source_name, message->reply_port(), name(), message->dest_port());
   }
+
+  Message::Priority priority = message->priority();
   message_queue()->Enqueue(message);
-  ASSERT(message->priority() < Message::kOOBPriority);
-  if (message->priority() >= Message::kOOBPriority) {
+  message = NULL;  // Do not access message.  May have been deleted.
+
+  ASSERT(priority < Message::kOOBPriority);

[siva, 2012/01/26 00:01:46]

Shouldn't this assert be after the if check?

+  if (priority >= Message::kOOBPriority) {
     // Handle out of band messages even if the isolate is busy.
     ScheduleInterrupts(Isolate::kMessageInterrupt);
   }
   Dart_MessageNotifyCallback callback = message_notify_callback();
   if (callback) {
     // Allow the embedder to handle message notification.
     (*callback)(Api::CastIsolate(this));
   }
 }
 
@@ skipping 304 matching lines @@
 }
 
 
 void Isolate::VisitWeakPersistentHandles(HandleVisitor* visitor) {
   if (api_state() != NULL) {
     api_state()->VisitWeakHandles(visitor);
   }
 }
 
 }  // namespace dart