[WIP] WebFonts cache-aware timeout adaption

third_party/WebKit/Source/core/fetch/Resource.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) 2006 Samuel Weinig (sam.weinig@gmail.com)
     Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 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
@@ skipping 294 matching lines @@
       m_preloadCount(0),
       m_preloadDiscoveryTime(0.0),
       m_cacheIdentifier(MemoryCache::defaultCacheIdentifier()),
       m_preloadResult(PreloadNotReferenced),
       m_type(type),
       m_status(NotStarted),
       m_needsSynchronousCacheHit(false),
       m_linkPreload(false),
       m_isRevalidating(false),
       m_isAlive(false),
+      m_isAddClientProhibited(false),
       m_options(options),
       m_responseTimestamp(currentTime()),
       m_cancelTimer(this, &Resource::cancelTimerFired),
       m_resourceRequest(request) {
   DCHECK_EQ(
       m_type,
       unsigned(
           type));  // m_type is a bitfield, so this tests careless updates of the enum.
   InstanceCounters::incrementCounter(InstanceCounters::ResourceCounter);
 
@@ skipping 354 matching lines @@
     }
   }
   if (!hasClientsOrObservers()) {
     m_isAlive = true;
     memoryCache()->makeLive(this);
   }
 }
 
 void Resource::addClient(ResourceClient* client,
                          PreloadReferencePolicy policy) {
+  DCHECK(!m_isAddClientProhibited);
+
   willAddClientOrObserver(policy);
 
   if (m_isRevalidating) {
     m_clients.add(client);
     return;
   }
 
   // If we have existing data to send to the new client and the resource type supprts it, send it asynchronously.
   if (!m_response.isNull() &&
       !shouldSendCachedDataSynchronouslyForType(getType()) &&
@@ skipping 368 matching lines @@
     case Resource::LinkPrefetch:
     case Resource::TextTrack:
     case Resource::Media:
     case Resource::Manifest:
       return false;
   }
   NOTREACHED();
   return false;
 }
 
+void Resource::willReloadAfterDiskCacheMiss() {
+  m_resourceRequest.deactivateCacheAwareLoading();

[yhirano, 2016/10/04 05:27:10]

DCHECK(!m_isAddClientProhibited);

[Shao-Chuan Lee, 2016/10/04 09:08:04]

Done.

+
+  m_isAddClientProhibited = true;

[kouhei (in TOK), 2016/10/03 08:11:47]

AutoReset
https://cs.chromium.org/chromium/src/third_party/WebKit/Source/wtf/AutoReset....

[Shao-Chuan Lee, 2016/10/04 01:39:46]

I made this a bit-field like other fields in Resource, and the address cannot be
taken for AutoReset. Maybe make this a debug-only field if there are memory
usage concerns?

[hiroshige, 2016/10/05 08:27:10]

Probably we can make a normal bool and use AutoReset, because I think we don't
have to save ~1 byte per Resource by sacrificing readability.

[Shao-Chuan Lee, 2016/10/07 08:10:06]

Now we have ProhibitAddRemoveClientInScope.

[kouhei (in TOK), 2016/10/20 10:43:07]

You are right. You may want to introduce your own ForbiddenScope here as in:
https://cs.chromium.org/chromium/src/third_party/WebKit/Source/wtf/Vector.h?q...

+  ResourceClientWalker<ResourceClient> w(m_clients);
+  while (ResourceClient* c = w.next()) {
+    c->willReloadAfterDiskCacheMiss(this);
+  }
+  m_isAddClientProhibited = false;
+}
+
 }  // namespace blink