Oilpan: Force a page navigation GC before starting a V8 GC

third_party/WebKit/Source/platform/heap/ThreadState.cpp

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 672 matching lines @@
     }
     if (gcType == V8MajorGC) {
 #if PRINT_HEAP_STATS
         dataLogF("Scheduled IdleGC\n");
 #endif
         scheduleIdleGC();
         return;
     }
 }
 
+void ThreadState::willStartV8GC()
+{
+    // Finish Oilpan's complete sweeping before running a V8 GC.
+    // This will let the GC collect more V8 objects.
+    //
+    // TODO(haraken): It's a bit too late for a major GC to schedule
+    // completeSweep() here, because gcPrologue for a major GC is called
+    // not at the point where the major GC started but at the point where
+    // the major GC requests object grouping.
+    completeSweep();
+
+    // The fact that the PageNavigation GC is scheduled means that there is
+    // a dead frame. In common cases, a sequence of Oilpan's GC => V8 GC =>
+    // Oilpan's GC is needed to collect the dead frame. So we force the
+    // PageNavigation GC before running the V8 GC.
+    if (gcState() == PageNavigationGCScheduled) {
+#if PRINT_HEAP_STATS
+        dataLogF("Scheduled PageNavigationGC\n");
+#endif
+        Heap::collectGarbage(HeapPointersOnStack, GCWithSweep, Heap::PageNavigationGC);
+    }
+}
+
 void ThreadState::schedulePageNavigationGCIfNeeded(float estimatedRemovalRatio)
 {
     ASSERT(checkThread());
     Heap::reportMemoryUsageForTracing();
 
 #if PRINT_HEAP_STATS
     dataLogF("ThreadState::schedulePageNavigationGCIfNeeded (estimatedRemovalRatio=%.2lf)\n", estimatedRemovalRatio);
 #endif
 
     if (isGCForbidden())
@@ skipping 935 matching lines @@
         json->beginArray(it->key.ascii().data());
         for (size_t age = 0; age <= maxHeapObjectAge; ++age)
             json->pushInteger(it->value.ages[age]);
         json->endArray();
     }
     TRACE_EVENT_OBJECT_SNAPSHOT_WITH_ID(TRACE_DISABLED_BY_DEFAULT("blink_gc"), statsName, this, json.release());
 }
 #endif
 
 } // namespace blink