IndexedDB: Ensure pending callbacks are fired before dispatcher is torn down

content/common/indexed_db/indexed_db_dispatcher.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/common/indexed_db/indexed_db_dispatcher.h"
 
 #include "base/lazy_instance.h"
 #include "base/threading/thread_local.h"
 #include "content/common/child_thread.h"
 #include "content/common/indexed_db/indexed_db_messages.h"
@@ skipping 36 matching lines @@
 }
 }  // unnamed namespace
 
 const size_t kMaxIDBValueSizeInBytes = 64 * 1024 * 1024;
 
 IndexedDBDispatcher::IndexedDBDispatcher() {
   g_idb_dispatcher_tls.Pointer()->Set(this);
 }
 
 IndexedDBDispatcher::~IndexedDBDispatcher() {
+
+  // Clear any pending callbacks - which may result in dispatch requests -
+  // before marking the dispatcher as deleted.
+  for (IDMap<WebKit::WebIDBCallbacks, IDMapOwnPointer>::iterator
+           it(&pending_callbacks_); !it.IsAtEnd(); it.Advance()) {
+    pending_callbacks_.Remove(it.GetCurrentKey());

[michaeln, 2012/10/24 19:54:49]

Odd that there's no .Clear() method on the IDMap<> collection?

+  }
+  for (IDMap<WebKit::WebIDBDatabaseCallbacks, IDMapOwnPointer>::iterator
+           it(&pending_database_callbacks_); !it.IsAtEnd(); it.Advance()) {
+    pending_database_callbacks_.Remove(it.GetCurrentKey());
+  }
+  for (IDMap<WebKit::WebIDBTransactionCallbacks, IDMapOwnPointer>::iterator
+           it(&pending_transaction_callbacks_); !it.IsAtEnd(); it.Advance()) {
+    pending_transaction_callbacks_.Remove(it.GetCurrentKey());
+  }
+
+  DCHECK(pending_callbacks_.IsEmpty());
+  DCHECK(pending_database_callbacks_.IsEmpty());
+  DCHECK(pending_transaction_callbacks_.IsEmpty());
+
   g_idb_dispatcher_tls.Pointer()->Set(kHasBeenDeleted);
 }
 
 IndexedDBDispatcher* IndexedDBDispatcher::ThreadSpecificInstance() {
   if (g_idb_dispatcher_tls.Pointer()->Get() == kHasBeenDeleted) {
     NOTREACHED() << "Re-instantiating TLS IndexedDBDispatcher.";
     g_idb_dispatcher_tls.Pointer()->Set(NULL);
   }
   if (g_idb_dispatcher_tls.Pointer()->Get())
     return g_idb_dispatcher_tls.Pointer()->Get();
@@ skipping 702 matching lines @@
 void IndexedDBDispatcher::ResetCursorPrefetchCaches(int32 exception_cursor_id) {
   typedef std::map<int32, RendererWebIDBCursorImpl*>::iterator Iterator;
   for (Iterator i = cursors_.begin(); i != cursors_.end(); ++i) {
     if (i->first == exception_cursor_id)
       continue;
     i->second->ResetPrefetchCache();
   }
 }
 
 }  // namespace content