Merge 92143 - .: REGRESSION (r39725?): Resources removed from document can not be freed until the...

Source/WebCore/loader/cache/CachedResourceLoader.cpp

 /*
     Copyright (C) 1998 Lars Knoll (knoll@mpi-hd.mpg.de)
     Copyright (C) 2001 Dirk Mueller (mueller@kde.org)
     Copyright (C) 2002 Waldo Bastian (bastian@kde.org)
     Copyright (C) 2004, 2005, 2006, 2008 Apple Inc. All rights reserved.
     Copyright (C) 2009 Torch Mobile Inc. http://www.torchmobile.com/
 
     This library is free software; you can redistribute it and/or
     modify it under the terms of the GNU Library General Public
     License as published by the Free Software Foundation; either
@@ skipping 68 matching lines @@
         return new CachedResource(request, CachedResource::LinkSubresource);
 #endif
     }
     ASSERT_NOT_REACHED();
     return 0;
 }
 
 CachedResourceLoader::CachedResourceLoader(Document* document)
     : m_document(document)
     , m_requestCount(0)
+    , m_garbageCollectDocumentResourcesTimer(this, &CachedResourceLoader::garbageCollectDocumentResourcesTimerFired)
     , m_autoLoadImages(true)
     , m_loadFinishing(false)
     , m_allowStaleResources(false)
 {
 }
 
 CachedResourceLoader::~CachedResourceLoader()
 {
     m_document = 0;
 
@@ skipping 466 matching lines @@
 #endif
     m_documentResources.remove(resource->url());
 }
 
 void CachedResourceLoader::loadDone()
 {
     m_loadFinishing = false;
     if (frame())
         frame()->loader()->loadDone();
     performPostLoadActions();
+
+    if (!m_garbageCollectDocumentResourcesTimer.isActive())
+        m_garbageCollectDocumentResourcesTimer.startOneShot(0);
+}
+
+// Garbage collecting m_documentResources is a workaround for the
+// CachedResourceHandles on the RHS being strong references. Ideally this
+// would be a weak map, however CachedResourceHandles perform additional
+// bookkeeping on CachedResources, so instead pseudo-GC them -- when the
+// reference count reaches 1, m_documentResources is the only reference, so
+// remove it from the map.
+void CachedResourceLoader::garbageCollectDocumentResourcesTimerFired(Timer<CachedResourceLoader>* timer)
+{
+    ASSERT_UNUSED(timer, timer == &m_garbageCollectDocumentResourcesTimer);
+
+    typedef Vector<String, 10> StringVector;
+    StringVector resourcesToDelete;
+
+    for (DocumentResourceMap::iterator it = m_documentResources.begin(); it != m_documentResources.end(); ++it) {
+        if (it->second->hasOneHandle()) {
+            resourcesToDelete.append(it->first);
+            it->second->setOwningCachedResourceLoader(0);
+        }
+    }
+
+    for (StringVector::const_iterator it = resourcesToDelete.begin(); it != resourcesToDelete.end(); ++it)
+        m_documentResources.remove(*it);
 }
 
 void CachedResourceLoader::performPostLoadActions()
 {
     checkForPendingPreloads();
     resourceLoadScheduler()->servePendingRequests();
 }
 
 void CachedResourceLoader::notifyLoadedFromMemoryCache(CachedResource* resource)
 {
@@ skipping 168 matching lines @@
     if (scripts)
         printf("SCRIPTS: %d (%d hits, hit rate %d%%)\n", scripts, scripts - scriptMisses, (scripts - scriptMisses) * 100 / scripts);
     if (stylesheets)
         printf("STYLESHEETS: %d (%d hits, hit rate %d%%)\n", stylesheets, stylesheets - stylesheetMisses, (stylesheets - stylesheetMisses) * 100 / stylesheets);
     if (images)
         printf("IMAGES:  %d (%d hits, hit rate %d%%)\n", images, images - imageMisses, (images - imageMisses) * 100 / images);
 }
 #endif
     
 }