Changeset 96432 in webkit for trunk/Source/JavaScriptCore/heap/Heap.cpp

Timestamp:

Sep 30, 2011, 3:23:33 PM (14 years ago)

Author:

[email protected]

Message:

2011-09-30 Oliver Hunt <​[email protected]>

Need a sensible GGC policy

Reviewed by Geoff Garen.

This replaces the existing random collection policy
with a deterministic policy based on nursery size.

• heap/AllocationSpace.cpp: (JSC::AllocationSpace::allocateSlowCase):
• heap/Heap.cpp: (JSC::Heap::Heap): (JSC::Heap::markRoots): (JSC::Heap::collect):
• heap/Heap.h:
• heap/MarkedSpace.cpp: (JSC::MarkedSpace::MarkedSpace): (JSC::MarkedSpace::resetAllocator):
• heap/MarkedSpace.h: (JSC::MarkedSpace::nurseryWaterMark): (JSC::MarkedSpace::allocate):

File:

• trunk/Source/JavaScriptCore/heap/Heap.cpp (modified) (6 diffs)

trunk/Source/JavaScriptCore/heap/Heap.cpp

@@ -215 +215 @@
     : m_heapSize(heapSize)
     , m_minBytesPerCycle(heapSizeForHint(heapSize))
+    , m_lastFullGCSize(0)
     , m_operationInProgress(NoOperation)
     , m_objectSpace(this)
@@ -454 +455 @@
 }
 
-void Heap::markRoots()
-{
+void Heap::markRoots(bool fullGC)
+{
+    UNUSED_PARAM(fullGC);
     ASSERT(isValidThreadState(m_globalData));
     if (m_operationInProgress != NoOperation)
@@ -474 +476 @@
 #if ENABLE(GGC)
     MarkedBlock::DirtyCellVector dirtyCells;
-    // Until we have a sensible policy we just random choose to perform
-    // young generation collections 90% of the time.
-    if (WTF::randomNumber() > 0.1)
+    if (!fullGC)
         m_objectSpace.gatherDirtyCells(dirtyCells);
     else
@@ -487 +487 @@
 
 #if ENABLE(GGC)
-    for (size_t i = 0; i < dirtyObjectCount; i++) {
+    size_t dirtyCellCount = dirtyCells.size();
+    for (size_t i = 0; i < dirtyCellCount; i++) {
         heapRootVisitor.visitChildren(dirtyCells[i]);
         visitor.drain();
@@ -600 +601 @@
     ASSERT(m_isSafeToCollect);
     JAVASCRIPTCORE_GC_BEGIN();
-    
+    bool fullGC = sweepToggle == DoSweep;
+    if (!fullGC)
+        fullGC = (capacity() > 4 * m_lastFullGCSize);  
     canonicalizeCellLivenessData();
-    markRoots();
+
+    markRoots(fullGC);
 
     harvestWeakReferences();
@@ -622 +626 @@
     // new bytes allocated) proportion, and seems to work well in benchmarks.
     size_t proportionalBytes = 2 * size();
+    if (fullGC)
+        m_lastFullGCSize = proportionalBytes / 2;
+    
     m_objectSpace.setHighWaterMark(max(proportionalBytes, m_minBytesPerCycle));
     JAVASCRIPTCORE_GC_END();