[heap] Do more incremental marking work in tasks.

src/heap/heap.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/heap/heap.h"
 
 #include "src/accessors.h"
 #include "src/api.h"
 #include "src/ast/context-slot-cache.h"
 #include "src/base/bits.h"
@@ skipping 919 matching lines @@
         static_cast<double>(external_memory_ -
                             external_memory_at_last_mark_compact_ -
                             kExternalAllocationSoftLimit) /
         external_memory_hard_limit();
     DCHECK_GE(1, pressure);
     const double kMaxStepSizeOnExternalLimit = 25;
     const double deadline = MonotonicallyIncreasingTimeInMs() +
                             pressure * kMaxStepSizeOnExternalLimit;
     incremental_marking()->AdvanceIncrementalMarking(
         deadline, IncrementalMarking::GC_VIA_STACK_GUARD,
-        IncrementalMarking::FORCE_COMPLETION);
+        IncrementalMarking::FORCE_COMPLETION, StepOrigin::kV8);
   }
 }
 
 
 void Heap::EnsureFillerObjectAtTop() {
   // There may be an allocation memento behind objects in new space. Upon
   // evacuation of a non-full new space (or if we are on the last page) there
   // may be uninitialized memory behind top. We fill the remainder of the page
   // with a filler.
   Address to_top = new_space_->top();
@@ skipping 96 matching lines @@
   }
 
   if (collector == MARK_COMPACTOR &&
       (gc_callback_flags & (kGCCallbackFlagForced |
                             kGCCallbackFlagCollectAllAvailableGarbage)) != 0) {
     isolate()->CountUsage(v8::Isolate::kForcedGC);
   }
 
   // Start incremental marking for the next cycle. The heap snapshot
   // generator needs incremental marking to stay off after it aborted.
-  if (!ShouldAbortIncrementalMarking()) {
+  // We do this only for scavener to avoid a loop where mark-compact

[Michael Lippautz, 2016/09/07 15:46:24]

nit: scavenger

+  // causes another mark-compact.
+  if (collector == SCAVENGER && !ShouldAbortIncrementalMarking()) {
     StartIncrementalMarkingIfAllocationLimitIsReached(kNoGCFlags,
                                                       kNoGCCallbackFlags);
   }
 
   return next_gc_likely_to_collect_more;
 }
 
 
 int Heap::NotifyContextDisposed(bool dependant_context) {
   if (!dependant_context) {
@@ skipping 3225 matching lines @@
 
 bool Heap::PerformIdleTimeAction(GCIdleTimeAction action,
                                  GCIdleTimeHeapState heap_state,
                                  double deadline_in_ms) {
   bool result = false;
   switch (action.type) {
     case DONE:
       result = true;
       break;
     case DO_INCREMENTAL_STEP: {
-      if (incremental_marking()->incremental_marking_job()->IdleTaskPending()) {
-        result = true;
-      } else {
-        incremental_marking()
-            ->incremental_marking_job()
-            ->NotifyIdleTaskProgress();
-        result = IncrementalMarkingJob::IdleTask::Step(this, deadline_in_ms) ==
-                 IncrementalMarkingJob::IdleTask::kDone;
+      const double remaining_idle_time_in_ms =
+          incremental_marking()->AdvanceIncrementalMarking(
+              deadline_in_ms, IncrementalMarking::NO_GC_VIA_STACK_GUARD,
+              IncrementalMarking::FORCE_COMPLETION, StepOrigin::kTask);
+      if (remaining_idle_time_in_ms > 0.0) {
+        TryFinalizeIdleIncrementalMarking(
+            remaining_idle_time_in_ms,
+            GarbageCollectionReason::kFinalizeMarkingViaTask);
       }
+      result = incremental_marking()->IsStopped();
       break;
     }
     case DO_FULL_GC: {
       DCHECK(contexts_disposed_ > 0);
       HistogramTimerScope scope(isolate_->counters()->gc_context());
       TRACE_EVENT0("v8", "V8.GCContext");
       CollectAllGarbage(kNoGCFlags, GarbageCollectionReason::kContextDisposal);
       break;
     }
     case DO_NOTHING:
@@ skipping 2207 matching lines @@
 }
 
 
 // static
 int Heap::GetStaticVisitorIdForMap(Map* map) {
   return StaticVisitorBase::GetVisitorId(map);
 }
 
 }  // namespace internal
 }  // namespace v8