From 5fd4b87267ba8f3c667533b0336554a7cc008876 Mon Sep 17 00:00:00 2001 From: wolfbeast Date: Wed, 15 May 2019 19:37:25 +0000 Subject: Remove unboxed objects from GC --- js/src/gc/Marking.cpp | 46 +--------------------------------- js/src/gc/Tracer.cpp | 69 ++------------------------------------------------- 2 files changed, 3 insertions(+), 112 deletions(-) (limited to 'js/src/gc') diff --git a/js/src/gc/Marking.cpp b/js/src/gc/Marking.cpp index 3ea4c9d29f..47d2314c1a 100644 --- a/js/src/gc/Marking.cpp +++ b/js/src/gc/Marking.cpp @@ -18,6 +18,7 @@ #include "builtin/ModuleObject.h" #include "gc/GCInternals.h" #include "gc/Policy.h" +#include "gc/StoreBuffer-inl.h" #include "jit/IonCode.h" #include "js/SliceBudget.h" #include "vm/ArgumentsObject.h" @@ -28,7 +29,6 @@ #include "vm/Shape.h" #include "vm/Symbol.h" #include "vm/TypedArrayObject.h" -#include "vm/UnboxedObject.h" #include "wasm/WasmJS.h" #include "jscompartmentinlines.h" @@ -37,7 +37,6 @@ #include "gc/Nursery-inl.h" #include "vm/String-inl.h" -#include "vm/UnboxedObject-inl.h" using namespace js; using namespace js::gc; @@ -1395,14 +1394,6 @@ js::ObjectGroup::traceChildren(JSTracer* trc) if (maybePreliminaryObjects()) maybePreliminaryObjects()->trace(trc); - if (maybeUnboxedLayout()) - unboxedLayout().trace(trc); - - if (ObjectGroup* unboxedGroup = maybeOriginalUnboxedGroup()) { - TraceManuallyBarrieredEdge(trc, &unboxedGroup, "group_original_unboxed_group"); - setOriginalUnboxedGroup(unboxedGroup); - } - if (JSObject* descr = maybeTypeDescr()) { TraceManuallyBarrieredEdge(trc, &descr, "group_type_descr"); setTypeDescr(&descr->as()); @@ -1436,12 +1427,6 @@ js::GCMarker::lazilyMarkChildren(ObjectGroup* group) if (group->maybePreliminaryObjects()) group->maybePreliminaryObjects()->trace(this); - if (group->maybeUnboxedLayout()) - group->unboxedLayout().trace(this); - - if (ObjectGroup* unboxedGroup = group->maybeOriginalUnboxedGroup()) - traverseEdge(group, unboxedGroup); - if (TypeDescr* descr = group->maybeTypeDescr()) traverseEdge(group, static_cast(descr)); @@ -1484,23 +1469,6 @@ CallTraceHook(Functor f, JSTracer* trc, JSObject* obj, CheckGeneration check, Ar return nullptr; } - if (clasp == &UnboxedPlainObject::class_) { - JSObject** pexpando = obj->as().addressOfExpando(); - if (*pexpando) - f(pexpando, mozilla::Forward(args)...); - - UnboxedPlainObject& unboxed = obj->as(); - const UnboxedLayout& layout = check == CheckGeneration::DoChecks - ? unboxed.layout() - : unboxed.layoutDontCheckGeneration(); - if (layout.traceList()) { - VisitTraceList(f, layout.traceList(), unboxed.data(), - mozilla::Forward(args)...); - } - - return nullptr; - } - clasp->doTrace(trc, obj); if (!clasp->isNative()) @@ -2293,18 +2261,6 @@ static inline void TraceWholeCell(TenuringTracer& mover, JSObject* object) { mover.traceObject(object); - - // Additionally trace the expando object attached to any unboxed plain - // objects. Baseline and Ion can write properties to the expando while - // only adding a post barrier to the owning unboxed object. Note that - // it isn't possible for a nursery unboxed object to have a tenured - // expando, so that adding a post barrier on the original object will - // capture any tenured->nursery edges in the expando as well. - - if (object->is()) { - if (UnboxedExpandoObject* expando = object->as().maybeExpando()) - expando->traceChildren(&mover); - } } static inline void diff --git a/js/src/gc/Tracer.cpp b/js/src/gc/Tracer.cpp index 63cd9b08a4..3416464ddf 100644 --- a/js/src/gc/Tracer.cpp +++ b/js/src/gc/Tracer.cpp @@ -201,80 +201,15 @@ gc::TraceCycleCollectorChildren(JS::CallbackTracer* trc, Shape* shape) } while (shape); } -// Object groups can point to other object groups via an UnboxedLayout or the -// the original unboxed group link. There can potentially be deep or cyclic -// chains of such groups to trace through without going through a thing that -// participates in cycle collection. These need to be handled iteratively to -// avoid blowing the stack when running the cycle collector's callback tracer. -struct ObjectGroupCycleCollectorTracer : public JS::CallbackTracer -{ - explicit ObjectGroupCycleCollectorTracer(JS::CallbackTracer* innerTracer) - : JS::CallbackTracer(innerTracer->runtime(), DoNotTraceWeakMaps), - innerTracer(innerTracer) - {} - - void onChild(const JS::GCCellPtr& thing) override; - - JS::CallbackTracer* innerTracer; - Vector seen, worklist; -}; - -void -ObjectGroupCycleCollectorTracer::onChild(const JS::GCCellPtr& thing) -{ - if (thing.is()) { - // The CC does not care about BaseShapes, and no additional GC things - // will be reached by following this edge. - return; - } - - if (thing.is() || thing.is()) { - // Invoke the inner cycle collector callback on this child. It will not - // recurse back into TraceChildren. - innerTracer->onChild(thing); - return; - } - - if (thing.is()) { - // If this group is required to be in an ObjectGroup chain, trace it - // via the provided worklist rather than continuing to recurse. - ObjectGroup& group = thing.as(); - if (group.maybeUnboxedLayout()) { - for (size_t i = 0; i < seen.length(); i++) { - if (seen[i] == &group) - return; - } - if (seen.append(&group) && worklist.append(&group)) { - return; - } else { - // If append fails, keep tracing normally. The worst that will - // happen is we end up overrecursing. - } - } - } - - TraceChildren(this, thing.asCell(), thing.kind()); -} - void gc::TraceCycleCollectorChildren(JS::CallbackTracer* trc, ObjectGroup* group) { MOZ_ASSERT(trc->isCallbackTracer()); - // Early return if this group is not required to be in an ObjectGroup chain. - if (!group->maybeUnboxedLayout()) - return group->traceChildren(trc); - - ObjectGroupCycleCollectorTracer groupTracer(trc->asCallbackTracer()); - group->traceChildren(&groupTracer); - - while (!groupTracer.worklist.empty()) { - ObjectGroup* innerGroup = groupTracer.worklist.popCopy(); - innerGroup->traceChildren(&groupTracer); - } + group->traceChildren(trc); } - + /*** Traced Edge Printer *************************************************************************/ static size_t -- cgit v1.2.3