Move idle notification handling to GCIdleTimeHandler.

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/v8.h"
 
 #include "src/accessors.h"
 #include "src/api.h"
 #include "src/base/once.h"
 #include "src/base/utils/random-number-generator.h"
@@ skipping 102 matching lines @@
       max_gc_pause_(0.0),
       total_gc_time_ms_(0.0),
       max_alive_after_gc_(0),
       min_in_mutator_(kMaxInt),
       marking_time_(0.0),
       sweeping_time_(0.0),
       mark_compact_collector_(this),
       store_buffer_(this),
       marking_(this),
       incremental_marking_(this),
-      number_idle_notifications_(0),
-      last_idle_notification_gc_count_(0),
-      last_idle_notification_gc_count_init_(false),
-      mark_sweeps_since_idle_round_started_(0),
       gc_count_at_last_idle_gc_(0),
-      scavenges_since_last_idle_round_(kIdleScavengeThreshold),
       full_codegen_bytes_generated_(0),
       crankshaft_codegen_bytes_generated_(0),
       gcs_since_last_deopt_(0),
 #ifdef VERIFY_HEAP
       no_weak_object_verification_scope_depth_(0),
 #endif
       allocation_sites_scratchpad_length_(0),
       promotion_queue_(this),
       configured_(false),
       external_string_table_(this),
@@ skipping 1413 matching lines @@
       new_space_.inline_allocation_limit_step());
 
   // Update how much has survived scavenge.
   IncrementYoungSurvivorsCounter(static_cast<int>(
       (PromotedSpaceSizeOfObjects() - survived_watermark) + new_space_.Size()));
 
   LOG(isolate_, ResourceEvent("scavenge", "end"));
 
   gc_state_ = NOT_IN_GC;
 
-  scavenges_since_last_idle_round_++;
+  gc_idle_time_handler_.NotifyScavenge();
 }
 
 
 String* Heap::UpdateNewSpaceReferenceInExternalStringTableEntry(Heap* heap,
                                                                 Object** p) {
   MapWord first_word = HeapObject::cast(*p)->map_word();
 
   if (!first_word.IsForwardingAddress()) {
     // Unreachable external string can be finalized.
     heap->FinalizeExternalString(String::cast(*p));
@@ skipping 2684 matching lines @@
   if (!IsHeapIterable()) {
     CollectAllGarbage(kMakeHeapIterableMask, "Heap::MakeHeapIterable");
   }
   if (mark_compact_collector()->sweeping_in_progress()) {
     mark_compact_collector()->EnsureSweepingCompleted();
   }
   DCHECK(IsHeapIterable());
 }
 
 
-void Heap::AdvanceIdleIncrementalMarking(int idle_time_in_ms) {
-  intptr_t step_size = GCIdleTimeHandler::EstimateMarkingStepSize(
-      idle_time_in_ms, tracer_.IncrementalMarkingSpeedInBytesPerMillisecond());
-
+void Heap::AdvanceIdleIncrementalMarking(intptr_t step_size) {
   incremental_marking()->Step(step_size,
                               IncrementalMarking::NO_GC_VIA_STACK_GUARD, true);
 
   if (incremental_marking()->IsComplete()) {
     bool uncommit = false;
     if (gc_count_at_last_idle_gc_ == gc_count_) {
       // No GC since the last full GC, the mutator is probably not active.
       isolate_->compilation_cache()->Clear();
       uncommit = true;
     }
     CollectAllGarbage(kReduceMemoryFootprintMask,
                       "idle notification: finalize incremental");
-    mark_sweeps_since_idle_round_started_++;
+    gc_idle_time_handler_.NotifyIdleFullGC();
     gc_count_at_last_idle_gc_ = gc_count_;
     if (uncommit) {
       new_space_.Shrink();
       UncommitFromSpace();
     }
   }
 }
 
 
 bool Heap::IdleNotification(int idle_time_in_ms) {
   // If incremental marking is off, we do not perform idle notification.
   if (!FLAG_incremental_marking) return true;
-
-  // Minimal hint that allows to do full GC.
-  const int kMinHintForFullGC = 100;
   isolate()->counters()->gc_idle_time_allotted_in_ms()->AddSample(
       idle_time_in_ms);
   HistogramTimerScope idle_notification_scope(
       isolate_->counters()->gc_idle_notification());
 
-  if (contexts_disposed_ > 0) {
-    contexts_disposed_ = 0;
-    int mark_sweep_time = Min(TimeMarkSweepWouldTakeInMs(), 1000);
-    if (idle_time_in_ms >= mark_sweep_time && !FLAG_expose_gc &&
-        incremental_marking()->IsStopped()) {
+  GCIdleTimeAction action = gc_idle_time_handler_.Compute(
+      idle_time_in_ms, contexts_disposed_, SizeOfObjects(),
+      incremental_marking()->IsStopped(), tracer());
+  contexts_disposed_ = 0;
+  bool result = false;
+  switch (action.type) {
+    case DO_INCREMENTAL_MARKING:
+      if (incremental_marking()->IsStopped()) {

[Hannes Payer (out of office), 2014/08/20 18:24:11]

I think this check should be in the Compute function.

[ulan, 2014/08/21 08:45:19]

Acknowledged.

+        incremental_marking()->Start();
+      }
+      AdvanceIdleIncrementalMarking(action.parameter);
+      break;
+    case DO_FULL_GC: {
       HistogramTimerScope scope(isolate_->counters()->gc_context());
-      CollectAllGarbage(kReduceMemoryFootprintMask,
-                        "idle notification: contexts disposed");
-    } else {
-      AdvanceIdleIncrementalMarking(idle_time_in_ms);
+      const char* message = contexts_disposed_
+                                ? "idle notification: contexts disposed"
+                                : "idle notification: finalize idle round";
+      CollectAllGarbage(kReduceMemoryFootprintMask, message);
+      gc_idle_time_handler_.NotifyIdleFullGC();
+      break;
     }
-
-    // After context disposal there is likely a lot of garbage remaining, reset
-    // the idle notification counters in order to trigger more incremental GCs
-    // on subsequent idle notifications.
-    StartIdleRound();
-    return false;
+    case DO_SCAVENGE:
+      CollectGarbage(NEW_SPACE, "idle notification: scavenge");
+      break;
+    case DO_NOTHING:
+      result = true;
+      break;
   }
-
-  // By doing small chunks of GC work in each IdleNotification,
-  // perform a round of incremental GCs and after that wait until
-  // the mutator creates enough garbage to justify a new round.
-  // An incremental GC progresses as follows:
-  // 1. many incremental marking steps,
-  // 2. one old space mark-sweep-compact,
-  // Use mark-sweep-compact events to count incremental GCs in a round.
-
-  if (mark_sweeps_since_idle_round_started_ >= kMaxMarkSweepsInIdleRound) {
-    if (EnoughGarbageSinceLastIdleRound()) {
-      StartIdleRound();
-    } else {
-      return true;
-    }
-  }
-
-  int remaining_mark_sweeps =
-      kMaxMarkSweepsInIdleRound - mark_sweeps_since_idle_round_started_;
-
-  if (incremental_marking()->IsStopped()) {
-    // 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.
-    if (remaining_mark_sweeps <= 2 && idle_time_in_ms >= kMinHintForFullGC) {
-      CollectAllGarbage(kReduceMemoryFootprintMask,
-                        "idle notification: finalize idle round");
-      mark_sweeps_since_idle_round_started_++;
-    } else {
-      incremental_marking()->Start();
-    }
-  }
-  if (!incremental_marking()->IsStopped()) {
-    AdvanceIdleIncrementalMarking(idle_time_in_ms);
-  }
-
-  if (mark_sweeps_since_idle_round_started_ >= kMaxMarkSweepsInIdleRound) {
-    FinishIdleRound();
-    return true;
-  }
-
   // If the IdleNotifcation is called with a large hint we will wait for
   // the sweepter threads here.
+  const int kMinHintForFullGC = 100;
   if (idle_time_in_ms >= kMinHintForFullGC &&
       mark_compact_collector()->sweeping_in_progress()) {

[Hannes Payer (out of office), 2014/08/20 18:24:11]

Should we do a SWEEP action., which is selected when the "hint" is large enough
and sweeping is in progress. WDYT?

[ulan, 2014/08/21 08:45:19]

Agreed, but let's do this in a separate CL to reduce risk of reverting CL.

     mark_compact_collector()->EnsureSweepingCompleted();
   }
 
-  return false;
+  return result;
 }
 
 
 #ifdef DEBUG
 
 void Heap::Print() {
   if (!HasBeenSetUp()) return;
   isolate()->PrintStack(stdout);
   AllSpaces spaces(this);
   for (Space* space = spaces.next(); space != NULL; space = spaces.next()) {
@@ skipping 1758 matching lines @@
       static_cast<int>(object_sizes_last_time_[index]));
   CODE_AGE_LIST_COMPLETE(ADJUST_LAST_TIME_OBJECT_COUNT)
 #undef ADJUST_LAST_TIME_OBJECT_COUNT
 
   MemCopy(object_counts_last_time_, object_counts_, sizeof(object_counts_));
   MemCopy(object_sizes_last_time_, object_sizes_, sizeof(object_sizes_));
   ClearObjectStats();
 }
 }
 }  // namespace v8::internal