Re-land: Distinguish beween final incremental mark-compact and full mark-compact event in IdleNotif…

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

 // 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.
 
 #ifndef V8_HEAP_GC_IDLE_TIME_HANDLER_H_
 #define V8_HEAP_GC_IDLE_TIME_HANDLER_H_
 
 #include "src/globals.h"
 
 namespace v8 {
@@ skipping 74 matching lines @@
   static const size_t kMaximumMarkingStepSize = 700 * MB;
 
   // We have to make sure that we finish the IdleNotification before
   // idle_time_in_ms. Hence, we conservatively prune our workload estimate.
   static const double kConservativeTimeRatio;
 
   // If we haven't recorded any mark-compact events yet, we use
   // conservative lower bound for the mark-compact speed.
   static const size_t kInitialConservativeMarkCompactSpeed = 2 * MB;
 
+  // If we haven't recorded any final incremental mark-compact events yet, we
+  // use conservative lower bound for the mark-compact speed.
+  static const size_t kInitialConservativeFinalIncrementalMarkCompactSpeed =
+      2 * MB;
+
   // Maximum mark-compact time returned by EstimateMarkCompactTime.
   static const size_t kMaxMarkCompactTimeInMs;
 
+  // Maximum final incremental mark-compact time returned by
+  // EstimateFinalIncrementalMarkCompactTime.
+  static const size_t kMaxFinalIncrementalMarkCompactTimeInMs;
+
   // Minimum time to finalize sweeping phase. The main thread may wait for
   // sweeper threads.
   static const size_t kMinTimeForFinalizeSweeping;
 
   // Number of idle mark-compact events, after which idle handler will finish
   // idle round.
   static const int kMaxMarkCompactsInIdleRound;
 
   // Number of scavenges that will trigger start of new idle round.
   static const int kIdleScavengeThreshold;
@@ skipping 13 matching lines @@
     void Print();
 
     int contexts_disposed;
     double contexts_disposal_rate;
     size_t size_of_objects;
     bool incremental_marking_stopped;
     bool can_start_incremental_marking;
     bool sweeping_in_progress;
     size_t mark_compact_speed_in_bytes_per_ms;
     size_t incremental_marking_speed_in_bytes_per_ms;
+    size_t final_incremental_mark_compact_speed_in_bytes_per_ms;
     size_t scavenge_speed_in_bytes_per_ms;
     size_t used_new_space_size;
     size_t new_space_capacity;
     size_t new_space_allocation_throughput_in_bytes_per_ms;
   };
 
   GCIdleTimeHandler()
       : mark_compacts_since_idle_round_started_(0),
         scavenges_since_last_idle_round_(0) {}
 
@@ skipping 10 matching lines @@
   }
 
   void NotifyScavenge() { ++scavenges_since_last_idle_round_; }
 
   static size_t EstimateMarkingStepSize(size_t idle_time_in_ms,
                                         size_t marking_speed_in_bytes_per_ms);
 
   static size_t EstimateMarkCompactTime(
       size_t size_of_objects, size_t mark_compact_speed_in_bytes_per_ms);
 
+  static size_t EstimateFinalIncrementalMarkCompactTime(
+      size_t size_of_objects, size_t mark_compact_speed_in_bytes_per_ms);
+
   static bool ShouldDoMarkCompact(size_t idle_time_in_ms,
                                   size_t size_of_objects,
                                   size_t mark_compact_speed_in_bytes_per_ms);
 
   static bool ShouldDoContextDisposalMarkCompact(bool context_disposed,
                                                  double contexts_disposal_rate);
 
+  static bool ShouldDoFinalIncrementalMarkCompact(
+      size_t idle_time_in_ms, size_t size_of_objects,
+      size_t final_incremental_mark_compact_speed_in_bytes_per_ms);
+
   static bool ShouldDoScavenge(
       size_t idle_time_in_ms, size_t new_space_size, size_t used_new_space_size,
       size_t scavenger_speed_in_bytes_per_ms,
       size_t new_space_allocation_throughput_in_bytes_per_ms);
 
  private:
   void StartIdleRound() { mark_compacts_since_idle_round_started_ = 0; }
   bool IsMarkCompactIdleRoundFinished() {
     return mark_compacts_since_idle_round_started_ ==
            kMaxMarkCompactsInIdleRound;
   }
   bool EnoughGarbageSinceLastIdleRound() {
     return scavenges_since_last_idle_round_ >= kIdleScavengeThreshold;
   }
 
   int mark_compacts_since_idle_round_started_;
   int scavenges_since_last_idle_round_;
 
   DISALLOW_COPY_AND_ASSIGN(GCIdleTimeHandler);
 };
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_HEAP_GC_IDLE_TIME_HANDLER_H_