JavaScriptCore: Changed GC from mark-sweep to mark-allocate.
        
Reviewed by Sam Weinig.

Added WeakGCMap to keep WebCore blissfully ignorant about objects that
have become garbage but haven't run their destructors yet.
        
1% SunSpider speedup.
7.6% v8 speedup (37% splay speedup).
17% speedup on bench-alloc-nonretained.js.
18% speedup on bench-alloc-retained.js.

* API/JSBase.cpp:
(JSGarbageCollect):
* API/JSContextRef.cpp:
* JavaScriptCore.exp:
* JavaScriptCore.xcodeproj/project.pbxproj: Updated for renames and new
files.

* debugger/Debugger.cpp:
(JSC::Debugger::recompileAllJSFunctions): Updated to use the Collector
iterator abstraction.

* jsc.cpp:
(functionGC): Updated for rename.

* runtime/Collector.cpp: Slightly reduced the number of allocations per
collection, so that small workloads only allocate on collector block,
rather than two.

(JSC::Heap::Heap): Updated to use the new allocateBlock function.

(JSC::Heap::destroy): Updated to use the new freeBlocks function.

(JSC::Heap::allocateBlock): New function to initialize a block when
allocating it.

(JSC::Heap::freeBlock): Consolidated the responsibility for running
destructors into this function.

(JSC::Heap::freeBlocks): Updated to use freeBlock.

(JSC::Heap::recordExtraCost): Sweep the heap in this reporting function,
so that allocation, which is more common, doesn't have to check extraCost.

(JSC::Heap::heapAllocate): Run destructors right before recycling a
garbage cell. This has better cache utilization than a separate sweep phase.

(JSC::Heap::resizeBlocks):
(JSC::Heap::growBlocks):
(JSC::Heap::shrinkBlocks): New set of functions for managing the size of
the heap, now that the heap doesn't maintain any information about its
size.

(JSC::isPointerAligned):
(JSC::isHalfCellAligned):
(JSC::isPossibleCell):
(JSC::isCellAligned):
(JSC::Heap::markConservatively): Cleaned up this code a bit.

(JSC::Heap::clearMarkBits):
(JSC::Heap::markedCells): Some helper functions for examining the the mark
bitmap.

(JSC::Heap::sweep): Simplified this function by using a DeadObjectIterator.

(JSC::Heap::markRoots): Reordered some operations for clarity.

(JSC::Heap::objectCount):
(JSC::Heap::addToStatistics):
(JSC::Heap::statistics): Rewrote these functions to calculate an object
count on demand, since the heap doesn't maintain this information by 
itself.

(JSC::Heap::reset): New function for resetting the heap once we've
exhausted heap space.

(JSC::Heap::collectAllGarbage): This function matches the old collect()
behavior, but it's now an uncommon function used only by API.

* runtime/Collector.h:
(JSC::CollectorBitmap::count):
(JSC::CollectorBitmap::isEmpty): Added some helper functions for managing
the collector mark bitmap.

(JSC::Heap::reportExtraMemoryCost): Changed reporting from cell equivalents
to bytes, so it's easier to understand.
        
* runtime/CollectorHeapIterator.h:
(JSC::CollectorHeapIterator::CollectorHeapIterator):
(JSC::CollectorHeapIterator::operator!=):
(JSC::CollectorHeapIterator::operator*):
(JSC::CollectorHeapIterator::advance):
(JSC::::LiveObjectIterator):
(JSC::::operator):
(JSC::::DeadObjectIterator):
(JSC::::ObjectIterator): New iterators for encapsulating details about
heap layout, and what's live and dead on the heap.

* runtime/JSArray.cpp:
(JSC::JSArray::putSlowCase):
(JSC::JSArray::increaseVectorLength): Delay reporting extra cost until
we're fully constructed, so the heap mark phase won't visit us in an
invalid state.

* runtime/JSCell.h:
(JSC::JSCell::):
(JSC::JSCell::createDummyStructure):
(JSC::JSCell::JSCell):
* runtime/JSGlobalData.cpp:
(JSC::JSGlobalData::JSGlobalData):
* runtime/JSGlobalData.h: Added a dummy cell to simplify allocation logic.

* runtime/JSString.h:
(JSC::jsSubstring): Don't report extra cost for substrings, since they
share a buffer that's already reported extra cost.

* runtime/Tracing.d:
* runtime/Tracing.h: Changed these dtrace hooks not to report object
counts, since they're no longer cheap to compute.

* runtime/UString.h: Updated for renames.

* runtime/WeakGCMap.h: Added.
(JSC::WeakGCMap::isEmpty):
(JSC::WeakGCMap::uncheckedGet):
(JSC::WeakGCMap::uncheckedBegin):
(JSC::WeakGCMap::uncheckedEnd):
(JSC::::get):
(JSC::::take):
(JSC::::set):
(JSC::::uncheckedRemove): Mentioned above.

* wtf/StdLibExtras.h:
(WTF::bitCount): Added a bit population count function, so the heap can
count live objects to fulfill statistics questions.

JavaScriptGlue: Changed GC from mark-sweep to mark-allocate.
        
Reviewed by Sam Weinig.

* JavaScriptGlue.cpp:
(JSCollect): Updated for rename. Fixed a bug where JSGlue would not check
to avoid nested GC calls.

WebCore: Changed GC from mark-sweep to mark-allocate.

Reviewed by Sam Weinig.

* ForwardingHeaders/runtime/WeakGCMap.h: Added.
* bindings/js/GCController.cpp:
(WebCore::collect):
(WebCore::GCController::gcTimerFired):
(WebCore::GCController::garbageCollectNow): Updated for rename.

* bindings/js/JSDOMBinding.cpp:
(WebCore::removeWrappers):
(WebCore::hasCachedDOMObjectWrapperUnchecked):
(WebCore::hasCachedDOMObjectWrapper):
(WebCore::hasCachedDOMNodeWrapperUnchecked):
(WebCore::forgetDOMObject):
(WebCore::forgetDOMNode):
(WebCore::isObservableThroughDOM):
(WebCore::markDOMNodesForDocument):
(WebCore::markDOMObjectWrapper):
(WebCore::markDOMNodeWrapper):
* bindings/js/JSDOMBinding.h: Changed DOM wrapper maps to be WeakGCMaps.
Don't ASSERT that an item must be in the WeakGCMap when its destructor
runs, since it might have been overwritten in the map first.

* bindings/js/JSDocumentCustom.cpp:
(WebCore::toJS): Changed Document from a DOM object wrapper to a DOM node
wrapper, to simplify some code.

* bindings/js/JSInspectedObjectWrapper.cpp:
(WebCore::JSInspectedObjectWrapper::JSInspectedObjectWrapper):
(WebCore::JSInspectedObjectWrapper::~JSInspectedObjectWrapper):
* bindings/js/JSInspectorCallbackWrapper.cpp: Use a WeakGCMap for these
wrappers.

* bindings/js/JSNodeCustom.cpp:
(WebCore::JSNode::markChildren): Updated for WeakGCMap and Document using
a DOM node wrapper instead of a DOM object wrapper.

* bindings/js/JSSVGPODTypeWrapper.h:
(WebCore::JSSVGDynamicPODTypeWrapperCache::wrapperMap):
(WebCore::JSSVGDynamicPODTypeWrapperCache::lookupOrCreateWrapper):
(WebCore::JSSVGDynamicPODTypeWrapperCache::forgetWrapper):
(WebCore::::~JSSVGDynamicPODTypeWrapper): Shined a small beam of sanity light
on this code. Use hashtable-based lookup in JSSVGPODTypeWrapper.h instead
of linear lookup through iteration, since that's what hashtables were
invented for. Make JSSVGPODTypeWrapper.h responsible for reomving itself
from the table, instead of its JS wrapper, to decouple these objects from
GC, and because these objects are refCounted, not solely owned by their
JS wrappers.

* bindings/scripts/CodeGeneratorJS.pm:
* dom/Document.h: Adopted changes above.



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@52082 268f45cc-cd09-0410-ab3c-d52691b4dbfc
diff --git a/JavaScriptCore/runtime/Tracing.h b/JavaScriptCore/runtime/Tracing.h
index e544f66..c28c85f 100644
--- a/JavaScriptCore/runtime/Tracing.h
+++ b/JavaScriptCore/runtime/Tracing.h
@@ -33,7 +33,7 @@
 #define JAVASCRIPTCORE_GC_BEGIN()
 #define JAVASCRIPTCORE_GC_BEGIN_ENABLED() 0
 
-#define JAVASCRIPTCORE_GC_END(arg0, arg1)
+#define JAVASCRIPTCORE_GC_END()
 #define JAVASCRIPTCORE_GC_END_ENABLED() 0
 
 #define JAVASCRIPTCORE_GC_MARKED()