collectAllGarbage(): bail on reaching fixed point.

Source/platform/heap/Heap.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 2378 matching lines @@
     ASSERT(s_markingStack->isEmpty());
 }
 
 void Heap::collectAllGarbage()
 {
     // FIXME: Oilpan: we should perform a single GC and everything
     // should die. Unfortunately it is not the case for all objects
     // because the hierarchy was not completely moved to the heap and
     // some heap allocated objects own objects that contain persistents
     // pointing to other heap allocated objects.
-    for (int i = 0; i < 5; ++i)
+    size_t previousLiveObjects = 0;
+    for (int i = 0; i < 5; ++i) {
         collectGarbage(ThreadState::NoHeapPointersOnStack, ThreadState::GCWithSweep, ForcedGCForTesting);
+        size_t liveObjects = Heap::estimatedLiveObjectSize();

[haraken, 2015/04/13 23:12:12]

Shall we use Heap::markedObjectSize()?

Conceptually Heap::estimatedLiveObjectSize() is a size calculated based on
Heap::markedObjectSize() with some heuristics.

[sof, 2015/04/14 06:40:51]

ok, let's leave estimatedLiveObjectSize() for the ThreadState shouldGC
predicates only to use.

+        if (liveObjects == previousLiveObjects)
+            break;
+        previousLiveObjects = liveObjects;
+    }
 }
 
 double Heap::estimatedMarkingTime()
 {
     ASSERT(ThreadState::current()->isMainThread());
 
     // Use 8 ms as initial estimated marking time.
     // 8 ms is long enough for low-end mobile devices to mark common
     // real-world object graphs.
     if (s_estimatedMarkingTimePerByte == 0)
@@ skipping 283 matching lines @@
 // We don't want to use 0 KB for the initial value because it may end up
 // triggering the first GC of some thread too prematurely.
 size_t Heap::s_estimatedLiveObjectSize = 512 * 1024;
 
 size_t Heap::s_externallyAllocatedBytes = 0;
 size_t Heap::s_externallyAllocatedBytesAlive = 0;
 unsigned Heap::s_requestedUrgentGC = false;
 double Heap::s_estimatedMarkingTimePerByte = 0.0;
 
 } // namespace blink