Add MemoryCoordinatorClient

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 86 matching lines @@
     , m_maxDeadCapacity(cDefaultCacheCapacity)
     , m_maxDeferredPruneDeadCapacity(cDeferredPruneDeadCapacityFactor * cDefaultCacheCapacity)
     , m_delayBeforeLiveDecodedPrune(cMinDelayBeforeLiveDecodedPrune)
     , m_liveSize(0)
     , m_deadSize(0)
 #ifdef MEMORY_CACHE_STATS
     , m_statsTimer(this, &MemoryCache::dumpStats)
 #endif
 {
     MemoryCacheDumpProvider::instance()->setMemoryCache(this);
+    MemoryCoordinator::instance().registerClient(this);
 #ifdef MEMORY_CACHE_STATS
     const double statsIntervalInSeconds = 15;
     m_statsTimer.startRepeating(statsIntervalInSeconds, BLINK_FROM_HERE);
 #endif
 }
 
 MemoryCache* MemoryCache::create()
 {
     return new MemoryCache;
 }
 
 MemoryCache::~MemoryCache()
 {
     if (m_prunePending)
         Platform::current()->currentThread()->removeTaskObserver(this);
+    MemoryCoordinator::instance().unregisterClient(this);

[haraken, 2016/08/12 02:55:00]

We don't need to call this since the client is automatically removed by Oilpan's
weak processing.

[bashi, 2016/08/16 00:09:06]

Removed.

Does it mean we should have null checks in MemoryCoordinator when it iterates
over |m_clients|?

[haraken, 2016/08/16 02:37:04]

No. Cleared entries are automatically removed from the HashSet by Oilpan, so you
don't need to worry about it. (Also it's guaranteed that Oilpan doesn't collect
the objects while someone is iterating the HashSet on the stack.)

[bashi, 2016/08/16 02:39:41]

I see. Thanks for clarification.

 }
 
 DEFINE_TRACE(MemoryCache)
 {
     visitor->trace(m_allResources);
     visitor->trace(m_liveDecodedResources);
     visitor->trace(m_resourceMaps);
     MemoryCacheDumpClient::trace(visitor);
+    MemoryCoordinatorClient::trace(visitor);
 }
 
 KURL MemoryCache::removeFragmentIdentifierIfNeeded(const KURL& originalURL)
 {
     if (!originalURL.hasFragmentIdentifier())
         return originalURL;
     // Strip away fragment identifier from HTTP URLs.
     // Data URLs must be unmodified. For file and custom URLs clients may expect resources
     // to be unique even when they differ by the fragment identifier only.
     if (!originalURL.protocolIsInHTTPFamily())
@@ skipping 588 matching lines @@
 {
     for (const auto& resourceMapIter : m_resourceMaps) {
         for (const auto& resourceIter : *resourceMapIter.value) {
             Resource* resource = resourceIter.value->resource();
             resource->onMemoryDump(levelOfDetail, memoryDump);
         }
     }
     return true;
 }
 
+void MemoryCache::onMemoryPressure(WebMemoryPressureLevel level)
+{
+    if (ProcessHeap::isLowEndDevice())

[esprehn, 2016/08/15 15:41:07]

Hmm, should we do this in the constructor then? Calling this method and having
it be a no-op seems strange.

[bashi, 2016/08/16 00:09:06]

Done.

tasak@: you might want to move back this condition when you implement
purgeMemory() interface in MemoryCache.

+        pruneAll();
+}
+
 bool MemoryCache::isInSameLRUListForTest(const Resource* x, const Resource* y)
 {
     MemoryCacheEntry* ex = getEntryForResource(x);
     MemoryCacheEntry* ey = getEntryForResource(y);
     ASSERT(ex);
     ASSERT(ey);
     return lruListFor(ex->m_accessCount, x->size()) == lruListFor(ey->m_accessCount, y->size());
 }
 
 #ifdef MEMORY_CACHE_STATS
@@ skipping 34 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