Move idle notification handling to GCIdleTimeHandler.

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

Index: src/heap/gc-idle-time-handler.h
diff --git a/src/heap/gc-idle-time-handler.h b/src/heap/gc-idle-time-handler.h
index 609fdb18ef71e25f0157b931a33d789c32214e61..76cdb9f21cd59d97fde49cc82382e73ffbd35427 100644
--- a/src/heap/gc-idle-time-handler.h
+++ b/src/heap/gc-idle-time-handler.h
@@ -10,13 +10,51 @@
 namespace v8 {
 namespace internal {
 
+enum GCIdleTimeActionType {
+  DO_NOTHING,
+  DO_INCREMENTAL_MARKING,
+  DO_SCAVENGE,
+  DO_FULL_GC
+};
+
+
+class GCIdleTimeAction {
+ public:
+  static GCIdleTimeAction Nothing() {
+    GCIdleTimeAction result;
+    result.type = DO_NOTHING;
+    result.parameter = 0;
+    return result;
+  }
+  static GCIdleTimeAction IncrementalMarking(intptr_t step_size) {
+    GCIdleTimeAction result;
+    result.type = DO_INCREMENTAL_MARKING;
+    result.parameter = step_size;
+    return result;
+  }
+  static GCIdleTimeAction Scavenge() {
+    GCIdleTimeAction result;
+    result.type = DO_SCAVENGE;
+    result.parameter = 0;
+    return result;
+  }
+  static GCIdleTimeAction FullGC() {
+    GCIdleTimeAction result;
+    result.type = DO_FULL_GC;
+    result.parameter = 0;
+    return result;
+  }
+
+  GCIdleTimeActionType type;
+  intptr_t parameter;
+};
+
+class GCTracer;
+
 // The idle time handler makes decisions about which garbage collection
 // operations are executing during IdleNotification.
 class GCIdleTimeHandler {
  public:
-  static size_t EstimateMarkingStepSize(size_t idle_time_in_ms,
-                                        size_t marking_speed_in_bytes_per_ms);
-
   // If we haven't recorded any incremental marking events yet, we carefully
   // mark with a conservative lower bound for the marking speed.
   static const size_t kInitialConservativeMarkingSpeed = 100 * KB;
@@ -28,7 +66,55 @@ class GCIdleTimeHandler {
   // 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;
+
+  // Maximum mark-compact time returned by EstimateMarkCompactTime.
+  static const size_t kMaxMarkCompactTimeInMs;
+
+  GCIdleTimeHandler()
+      : mark_compacts_since_idle_round_started_(0),
+        scavenges_since_last_idle_round_(0) {}
+
+  GCIdleTimeAction Compute(int idle_time_in_ms, int contexts_disposed,
+                           size_t size_of_objects,
+                           bool incremental_marking_stopped,
+                           GCTracer* gc_tracer);
+
+  void NotifyIdleMarkCompact() {
+    if (mark_compacts_since_idle_round_started_ < kMaxMarkCompactsInIdleRound) {
+      ++mark_compacts_since_idle_round_started_;
+      if (mark_compacts_since_idle_round_started_ ==
+          kMaxMarkCompactsInIdleRound) {
+        scavenges_since_last_idle_round_ = 0;
+      }
+    }
+  }
+
+  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);
+
  private:
+  void StartIdleRound() { mark_compacts_since_idle_round_started_ = 0; }
+  bool IsIdleRoundFinished() {
+    return mark_compacts_since_idle_round_started_ ==
+           kMaxMarkCompactsInIdleRound;
+  }
+  bool EnoughGarbageSinceLastIdleRound() {
+    return scavenges_since_last_idle_round_ >= kIdleScavengeThreshold;
+  }
+
+  static const int kMaxMarkCompactsInIdleRound = 7;
+  static const int kIdleScavengeThreshold = 5;
+  int mark_compacts_since_idle_round_started_;
+  int scavenges_since_last_idle_round_;
+
   DISALLOW_COPY_AND_ASSIGN(GCIdleTimeHandler);
 };