Prevent FontResource load limit timers from restarting during loading

third_party/WebKit/Source/core/fetch/FontResource.cpp

 /*
  * Copyright (C) 2006, 2007, 2008 Apple Inc. All rights reserved.
  * Copyright (C) 2009 Torch Mobile, Inc.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 67 matching lines @@
       WebURLRequest::RequestContextFont);
   return toFontResource(
       fetcher->requestResource(request, FontResourceFactory()));
 }
 
 FontResource::FontResource(const ResourceRequest& resourceRequest,
                            const ResourceLoaderOptions& options)
     : Resource(resourceRequest, Font, options),
       m_loadLimitState(UnderLimit),
       m_corsFailed(false),
+      m_isLoadLimitTimersStarted(false),
       m_fontLoadShortLimitTimer(this,
                                 &FontResource::fontLoadShortLimitCallback),
       m_fontLoadLongLimitTimer(this, &FontResource::fontLoadLongLimitCallback) {
 }
 
 FontResource::~FontResource() {}
 
 void FontResource::didAddClient(ResourceClient* c) {
   DCHECK(FontResourceClient::isExpectedType(c));
   Resource::didAddClient(c);
   if (m_loadLimitState == ShortLimitExceeded ||
       m_loadLimitState == LongLimitExceeded)
     static_cast<FontResourceClient*>(c)->fontLoadShortLimitExceeded(this);
   if (m_loadLimitState == LongLimitExceeded)
     static_cast<FontResourceClient*>(c)->fontLoadLongLimitExceeded(this);
 }
 
 void FontResource::setRevalidatingRequest(const ResourceRequest& request) {
   // Reload will use the same object, and needs to reset |m_loadLimitState|
   // before any didAddClient() is called again.
   m_loadLimitState = UnderLimit;
   Resource::setRevalidatingRequest(request);
 }
 
-void FontResource::startLoadLimitTimersIfNeeded() {
-  DCHECK(!stillNeedsLoad());
-  if (isLoaded() || m_fontLoadLongLimitTimer.isActive())
-    return;
+void FontResource::startLoadLimitTimers() {
+  DCHECK(!m_isLoadLimitTimersStarted);

[Kunihiko Sakamoto, 2016/10/13 05:55:19]

Can you add DCHECK(isLoading()) here?

[Shao-Chuan Lee, 2016/10/13 06:12:58]

Done.

   DCHECK_EQ(m_loadLimitState, UnderLimit);
   m_fontLoadShortLimitTimer.startOneShot(fontLoadWaitShortLimitSec,
                                          BLINK_FROM_HERE);
   m_fontLoadLongLimitTimer.startOneShot(fontLoadWaitLongLimitSec,
                                         BLINK_FROM_HERE);
+  m_isLoadLimitTimersStarted = true;
 }
 
 bool FontResource::ensureCustomFontData() {
   if (!m_fontData && !errorOccurred() && !isLoading()) {
     if (data())
       m_fontData = FontCustomPlatformData::create(data(), m_otsParsingMessage);
 
     if (m_fontData) {
       recordPackageFormatHistogram(packageFormatOf(data()));
     } else {
@@ skipping 34 matching lines @@
 }
 
 void FontResource::allClientsAndObserversRemoved() {
   m_fontData.reset();
   Resource::allClientsAndObserversRemoved();
 }
 
 void FontResource::checkNotify() {
   m_fontLoadShortLimitTimer.stop();
   m_fontLoadLongLimitTimer.stop();
+  m_isLoadLimitTimersStarted = false;

[Kunihiko Sakamoto, 2016/10/13 05:55:19]

Does this mean startLoadLimitTimers() can be called again?

[Shao-Chuan Lee, 2016/10/13 06:12:58]

Yes, in revalidation cases.

[Kunihiko Sakamoto, 2016/10/13 06:36:18]

Hm, then we have to reset m_loadLimitState too?
Can we remove m_isLoadLimitTimersStarted flag by introducing a new state to
LoadLimitState?

[Shao-Chuan Lee, 2016/10/13 07:14:06]

Adding new LoadLimitState to indicate that timers are not yet started. This
looks more consistent, thanks.

 
   Resource::checkNotify();
 }
 
 }  // namespace blink