Re-land "Add finalize sweeping event to GCIdleTimeHandler."

src/heap/gc-idle-time-handler.cc

 // Copyright 2014 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/gc-idle-time-handler.h"
 #include "src/heap/gc-tracer.h"
 #include "src/utils.h"
 
 namespace v8 {
 namespace internal {
 
 const double GCIdleTimeHandler::kConservativeTimeRatio = 0.9;
 const size_t GCIdleTimeHandler::kMaxMarkCompactTimeInMs = 1000000;
+const size_t GCIdleTimeHandler::kMinTimeForFinalizeSweeping = 100;
 
 
 size_t GCIdleTimeHandler::EstimateMarkingStepSize(
     size_t idle_time_in_ms, size_t marking_speed_in_bytes_per_ms) {
   DCHECK(idle_time_in_ms > 0);
 
   if (marking_speed_in_bytes_per_ms == 0) {
     marking_speed_in_bytes_per_ms = kInitialConservativeMarkingSpeed;
   }
 
   size_t marking_step_size = marking_speed_in_bytes_per_ms * idle_time_in_ms;
   if (marking_step_size / marking_speed_in_bytes_per_ms != idle_time_in_ms) {
     // In the case of an overflow we return maximum marking step size.
     return kMaximumMarkingStepSize;
   }
 
   if (marking_step_size > kMaximumMarkingStepSize)
     return kMaximumMarkingStepSize;
 
-  return static_cast<size_t>(marking_step_size *
-                             GCIdleTimeHandler::kConservativeTimeRatio);
+  return static_cast<size_t>(marking_step_size * kConservativeTimeRatio);
 }
 
 
 size_t GCIdleTimeHandler::EstimateMarkCompactTime(
     size_t size_of_objects, size_t mark_compact_speed_in_bytes_per_ms) {
   if (mark_compact_speed_in_bytes_per_ms == 0) {
     mark_compact_speed_in_bytes_per_ms = kInitialConservativeMarkCompactSpeed;
   }
   size_t result = size_of_objects / mark_compact_speed_in_bytes_per_ms;
   return Min(result, kMaxMarkCompactTimeInMs);
 }
 
 
-GCIdleTimeAction GCIdleTimeHandler::Compute(int idle_time_in_ms,
+GCIdleTimeAction GCIdleTimeHandler::Compute(size_t idle_time_in_ms,
                                             HeapState heap_state,
                                             GCTracer* gc_tracer) {
   if (IsIdleRoundFinished()) {
     if (EnoughGarbageSinceLastIdleRound() || heap_state.contexts_disposed > 0) {
       StartIdleRound();
     } else {
       return GCIdleTimeAction::Nothing();
     }
   }
   if (heap_state.incremental_marking_stopped) {
     size_t speed =
         static_cast<size_t>(gc_tracer->MarkCompactSpeedInBytesPerMillisecond());
-    if (idle_time_in_ms >= static_cast<int>(EstimateMarkCompactTime(
-                               heap_state.size_of_objects, speed))) {
+    if (idle_time_in_ms >=
+        EstimateMarkCompactTime(heap_state.size_of_objects, speed)) {
       // If there are no more than two GCs left in this idle round and we are
       // allowed to do a full GC, then make those GCs full in order to compact
       // the code space.
       // TODO(ulan): Once we enable code compaction for incremental marking, we
       // can get rid of this special case and always start incremental marking.
       int remaining_mark_sweeps =
           kMaxMarkCompactsInIdleRound - mark_compacts_since_idle_round_started_;
       if (heap_state.contexts_disposed > 0 || remaining_mark_sweeps <= 2 ||
           !heap_state.can_start_incremental_marking) {
         return GCIdleTimeAction::FullGC();
       }
     }
     if (!heap_state.can_start_incremental_marking) {
       return GCIdleTimeAction::Nothing();
     }
   }
+  // TODO(hpayer): Estimate finalize sweeping time.
+  if (heap_state.sweeping_in_progress &&
+      idle_time_in_ms >= kMinTimeForFinalizeSweeping) {
+    return GCIdleTimeAction::FinalizeSweeping();
+  }
+
   intptr_t speed = gc_tracer->IncrementalMarkingSpeedInBytesPerMillisecond();
   size_t step_size =
       static_cast<size_t>(EstimateMarkingStepSize(idle_time_in_ms, speed));
   return GCIdleTimeAction::IncrementalMarking(step_size);
 }
 }
 }