Perform context disposal garbage collections only if contexts disposals happen at a high rate.

test/unittests/heap/gc-idle-time-handler-unittest.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 <limits>
 
 #include "src/heap/gc-idle-time-handler.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace v8 {
 namespace internal {
 
 namespace {
 
 class GCIdleTimeHandlerTest : public ::testing::Test {
  public:
   GCIdleTimeHandlerTest() {}
   virtual ~GCIdleTimeHandlerTest() {}
 
   GCIdleTimeHandler* handler() { return &handler_; }
 
   GCIdleTimeHandler::HeapState DefaultHeapState() {
     GCIdleTimeHandler::HeapState result;
     result.contexts_disposed = 0;
+    result.contexts_disposal_rate = GCIdleTimeHandler::kHighContextDisposalRate;
     result.size_of_objects = kSizeOfObjects;
     result.incremental_marking_stopped = false;
     result.can_start_incremental_marking = true;
     result.sweeping_in_progress = false;
     result.mark_compact_speed_in_bytes_per_ms = kMarkCompactSpeed;
     result.incremental_marking_speed_in_bytes_per_ms = kMarkingSpeed;
     result.scavenge_speed_in_bytes_per_ms = kScavengeSpeed;
     result.used_new_space_size = 0;
     result.new_space_capacity = kNewSpaceCapacity;
     result.new_space_allocation_throughput_in_bytes_per_ms =
@@ skipping 137 matching lines @@
 }
 
 
 TEST_F(GCIdleTimeHandlerTest, DontDoMarkCompact) {
   size_t idle_time_in_ms = 1;
   EXPECT_FALSE(GCIdleTimeHandler::ShouldDoMarkCompact(
       idle_time_in_ms, kSizeOfObjects, kMarkingSpeed));
 }
 
 
+TEST_F(GCIdleTimeHandlerTest, ContextDisposeLowRate) {
+  GCIdleTimeHandler::HeapState heap_state = DefaultHeapState();
+  heap_state.contexts_disposed = 1;
+  heap_state.incremental_marking_stopped = true;
+  int idle_time_ms = 0;
+  GCIdleTimeAction action = handler()->Compute(idle_time_ms, heap_state);
+  EXPECT_EQ(DO_NOTHING, action.type);
+}
+
+
+TEST_F(GCIdleTimeHandlerTest, ContextDisposeHighRate) {
+  GCIdleTimeHandler::HeapState heap_state = DefaultHeapState();
+  heap_state.contexts_disposed = 1;
+  heap_state.contexts_disposal_rate =
+      GCIdleTimeHandler::kHighContextDisposalRate - 1;
+  heap_state.incremental_marking_stopped = true;
+  int idle_time_ms = 0;
+  GCIdleTimeAction action = handler()->Compute(idle_time_ms, heap_state);
+  EXPECT_EQ(DO_NOTHING, action.type);
+}
+
+
 TEST_F(GCIdleTimeHandlerTest, AfterContextDisposeLargeIdleTime) {
   GCIdleTimeHandler::HeapState heap_state = DefaultHeapState();
   heap_state.contexts_disposed = 1;
+  heap_state.contexts_disposal_rate = 1.0;
   heap_state.incremental_marking_stopped = true;
+  heap_state.can_start_incremental_marking = false;
   size_t speed = heap_state.mark_compact_speed_in_bytes_per_ms;
   int idle_time_ms =
       static_cast<int>((heap_state.size_of_objects + speed - 1) / speed);
   GCIdleTimeAction action = handler()->Compute(idle_time_ms, heap_state);
   EXPECT_EQ(DO_FULL_GC, action.type);
 }
 
 
 TEST_F(GCIdleTimeHandlerTest, AfterContextDisposeZeroIdleTime) {
   GCIdleTimeHandler::HeapState heap_state = DefaultHeapState();
   heap_state.contexts_disposed = 1;
+  heap_state.contexts_disposal_rate = 1.0;
   heap_state.incremental_marking_stopped = true;
   heap_state.size_of_objects = GCIdleTimeHandler::kSmallHeapSize / 2;
   int idle_time_ms = 0;
   GCIdleTimeAction action = handler()->Compute(idle_time_ms, heap_state);
   EXPECT_EQ(DO_FULL_GC, action.type);
 }
 
 
 TEST_F(GCIdleTimeHandlerTest, AfterContextDisposeSmallIdleTime1) {
   GCIdleTimeHandler::HeapState heap_state = DefaultHeapState();
   heap_state.contexts_disposed = 1;
+  heap_state.contexts_disposal_rate = 1.0;
   heap_state.incremental_marking_stopped = true;
   size_t speed = heap_state.mark_compact_speed_in_bytes_per_ms;
   int idle_time_ms = static_cast<int>(heap_state.size_of_objects / speed - 1);
   GCIdleTimeAction action = handler()->Compute(idle_time_ms, heap_state);
   EXPECT_EQ(DO_INCREMENTAL_MARKING, action.type);
 }
 
 
 TEST_F(GCIdleTimeHandlerTest, AfterContextDisposeSmallIdleTime2) {
   GCIdleTimeHandler::HeapState heap_state = DefaultHeapState();
   heap_state.contexts_disposed = 1;
+  heap_state.contexts_disposal_rate = 1.0;
   size_t speed = heap_state.mark_compact_speed_in_bytes_per_ms;
   int idle_time_ms = static_cast<int>(heap_state.size_of_objects / speed - 1);
   GCIdleTimeAction action = handler()->Compute(idle_time_ms, heap_state);
   EXPECT_EQ(DO_INCREMENTAL_MARKING, action.type);
 }
 
 
 TEST_F(GCIdleTimeHandlerTest, IncrementalMarking1) {
   GCIdleTimeHandler::HeapState heap_state = DefaultHeapState();
   size_t speed = heap_state.incremental_marking_speed_in_bytes_per_ms;
@@ skipping 158 matching lines @@
   // Emulate mutator work.
   for (int i = 0; i < GCIdleTimeHandler::kIdleScavengeThreshold; i++) {
     handler()->NotifyScavenge();
   }
   action = handler()->Compute(0, heap_state);
   EXPECT_EQ(DO_NOTHING, action.type);
 }
 
 }  // namespace internal
 }  // namespace v8