Remove SharedBuffer::unlock() and keep Resource's SharedBuffer always locked

third_party/WebKit/Source/core/fetch/MemoryCache.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, 2007, 2008 Apple Inc. All rights reserved.
 
     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
     version 2 of the License, or (at your option) any later version.
@@ skipping 183 matching lines @@
     if (!resourceURL.isValid() || resourceURL.isNull())
         return nullptr;
     ASSERT(!cacheIdentifier.isNull());
     ResourceMap* resources = m_resourceMaps.get(cacheIdentifier);
     if (!resources)
         return nullptr;
     KURL url = removeFragmentIdentifierIfNeeded(resourceURL);
     MemoryCacheEntry* entry = resources->get(url);
     if (!entry)
         return nullptr;
-    Resource* resource = entry->resource();
-    if (resource && !resource->lock())
-        return nullptr;
-    return resource;
+    return entry->resource();
 }
 
 HeapVector<Member<Resource>> MemoryCache::resourcesForURL(const KURL& resourceURL)
 {
     ASSERT(WTF::isMainThread());
     KURL url = removeFragmentIdentifierIfNeeded(resourceURL);
     HeapVector<Member<Resource>> results;
     for (const auto& resourceMapIter : m_resourceMaps) {
         if (MemoryCacheEntry* entry = resourceMapIter.value->get(url))
             results.append(entry->resource());
@@ skipping 357 matching lines @@
 
 void MemoryCache::removeURLFromCache(const KURL& url)
 {
     HeapVector<Member<Resource>> resources = resourcesForURL(url);
     for (Resource* resource : resources)
         memoryCache()->remove(resource);
 }
 
 void MemoryCache::TypeStatistic::addResource(Resource* o)
 {
-    bool purgeable = o->isPurgeable();
-    size_t pageSize = (o->encodedSize() + o->overheadSize() + 4095) & ~4095;
     count++;
     size += o->size();
     liveSize += o->hasClientsOrObservers() ? o->size() : 0;
     decodedSize += o->decodedSize();
     encodedSize += o->encodedSize();
     encodedSizeDuplicatedInDataURLs += o->url().protocolIsData() ? o->encodedSize() : 0;
-    purgeableSize += purgeable ? pageSize : 0;

[haraken, 2016/08/17 08:13:31]

Can you remove the purgeableSize member entirely?

[hiroshige, 2016/08/17 09:02:37]

Yes.
Created a separate CL: https://codereview.chromium.org/2254593003/.

 }
 
 MemoryCache::Statistics MemoryCache::getStatistics()
 {
     Statistics stats;
     for (const auto& resourceMapIter : m_resourceMaps) {
         for (const auto& resourceIter : *resourceMapIter.value) {
             Resource* resource = resourceIter.value->resource();
             switch (resource->getType()) {
             case Resource::Image:
@@ skipping 178 matching lines @@
                 printf("(%.1fK, %.1fK, %uA, %dR, %d); ", currentResource->decodedSize() / 1024.0f, (currentResource->encodedSize() + currentResource->overheadSize()) / 1024.0f, current->m_accessCount, currentResource->hasClientsOrObservers(), currentResource->isPurgeable());
 
             current = current->m_previousInAllResourcesList;
         }
     }
 }
 
 #endif // MEMORY_CACHE_STATS
 
 } // namespace blink