Use size_t in GCIdleTimeHandler to fix undefined behaviour.

BUG=
R=bmeurer@chromium.org

Review URL: https://codereview.chromium.org/490943002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@23248 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

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 <climits>
-
-#include "src/v8.h"
 
 #include "src/heap/gc-idle-time-handler.h"
 
@@ -14,8 +11,8 @@ namespace internal {
 const double GCIdleTimeHandler::kConservativeTimeRatio = 0.9;
 
 
-intptr_t GCIdleTimeHandler::EstimateMarkingStepSize(
-    int idle_time_in_ms, intptr_t marking_speed_in_bytes_per_ms) {
+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) {
@@ -23,16 +20,17 @@ intptr_t GCIdleTimeHandler::EstimateMarkingStepSize(
         GCIdleTimeHandler::kInitialConservativeMarkingSpeed;
   }
 
-  intptr_t marking_step_size = marking_speed_in_bytes_per_ms * idle_time_in_ms;
-  if (static_cast<intptr_t>(marking_step_size / idle_time_in_ms) !=
-      marking_speed_in_bytes_per_ms) {
+  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 INT_MAX;
+    return GCIdleTimeHandler::kMaximumMarkingStepSize;
   }
 
-  return Min(static_cast<intptr_t>(marking_step_size *
-                                   GCIdleTimeHandler::kConservativeTimeRatio),
-             static_cast<intptr_t>(INT_MAX));
+  if (marking_step_size > kMaximumMarkingStepSize)
+    return kMaximumMarkingStepSize;
+
+  return static_cast<size_t>(marking_step_size *
+                             GCIdleTimeHandler::kConservativeTimeRatio);
 }
 }
 }

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

@@ -14,12 +14,15 @@ namespace internal {
 // operations are executing during IdleNotification.
 class GCIdleTimeHandler {
  public:
-  static intptr_t EstimateMarkingStepSize(
-      int idle_time_in_ms, intptr_t marking_speed_in_bytes_per_ms);
+  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 intptr_t kInitialConservativeMarkingSpeed = 100 * KB;
+  static const size_t kInitialConservativeMarkingSpeed = 100 * KB;
+
+  // Maximum marking step size returned by EstimateMarkingStepSize.
+  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.

src/heap/heap.cc

@@ -4265,8 +4265,10 @@ void Heap::MakeHeapIterable() {
 
 
 void Heap::AdvanceIdleIncrementalMarking(int idle_time_in_ms) {
-  intptr_t step_size = GCIdleTimeHandler::EstimateMarkingStepSize(
-      idle_time_in_ms, tracer_.IncrementalMarkingSpeedInBytesPerMillisecond());
+  intptr_t step_size =
+      static_cast<size_t>(GCIdleTimeHandler::EstimateMarkingStepSize(
+          idle_time_in_ms,
+          tracer_.IncrementalMarkingSpeedInBytesPerMillisecond()));
 
   incremental_marking()->Step(step_size,
                               IncrementalMarking::NO_GC_VIA_STACK_GUARD, true);

src/heap/spaces.cc

@@ -2738,6 +2738,9 @@ void PagedSpace::ReportStatistics() {
          Capacity(), Waste(), Available(), pct);
 
   if (!swept_precisely_) return;
+  if (heap()->mark_compact_collector()->sweeping_in_progress()) {
+    heap()->mark_compact_collector()->EnsureSweepingCompleted();
+  }
   ClearHistograms(heap()->isolate());
   HeapObjectIterator obj_it(this);
   for (HeapObject* obj = obj_it.Next(); obj != NULL; obj = obj_it.Next())

test/heap-unittests/heap-unittest.cc

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include <climits>
+#include <limits>
 
 #include "src/heap/gc-idle-time-handler.h"
 
@@ -12,33 +12,37 @@ namespace v8 {
 namespace internal {
 
 TEST(EstimateMarkingStepSizeTest, EstimateMarkingStepSizeInitial) {
-  intptr_t step_size = GCIdleTimeHandler::EstimateMarkingStepSize(1, 0);
-  EXPECT_EQ(static_cast<intptr_t>(
-                GCIdleTimeHandler::kInitialConservativeMarkingSpeed *
-                GCIdleTimeHandler::kConservativeTimeRatio),
-            step_size);
+  size_t step_size = GCIdleTimeHandler::EstimateMarkingStepSize(1, 0);
+  EXPECT_EQ(
+      static_cast<size_t>(GCIdleTimeHandler::kInitialConservativeMarkingSpeed *
+                          GCIdleTimeHandler::kConservativeTimeRatio),
+      step_size);
 }
 
 
 TEST(EstimateMarkingStepSizeTest, EstimateMarkingStepSizeNonZero) {
-  intptr_t marking_speed_in_bytes_per_millisecond = 100;
-  intptr_t step_size = GCIdleTimeHandler::EstimateMarkingStepSize(
+  size_t marking_speed_in_bytes_per_millisecond = 100;
+  size_t step_size = GCIdleTimeHandler::EstimateMarkingStepSize(
       1, marking_speed_in_bytes_per_millisecond);
-  EXPECT_EQ(static_cast<intptr_t>(marking_speed_in_bytes_per_millisecond *
-                                  GCIdleTimeHandler::kConservativeTimeRatio),
+  EXPECT_EQ(static_cast<size_t>(marking_speed_in_bytes_per_millisecond *
+                                GCIdleTimeHandler::kConservativeTimeRatio),
             step_size);
 }
 
 
 TEST(EstimateMarkingStepSizeTest, EstimateMarkingStepSizeOverflow1) {
-  intptr_t step_size = GCIdleTimeHandler::EstimateMarkingStepSize(10, INT_MAX);
-  EXPECT_EQ(INT_MAX, step_size);
+  size_t step_size = GCIdleTimeHandler::EstimateMarkingStepSize(
+      10, std::numeric_limits<size_t>::max());
+  EXPECT_EQ(static_cast<size_t>(GCIdleTimeHandler::kMaximumMarkingStepSize),
+            step_size);
 }
 
 
 TEST(EstimateMarkingStepSizeTest, EstimateMarkingStepSizeOverflow2) {
-  intptr_t step_size = GCIdleTimeHandler::EstimateMarkingStepSize(INT_MAX, 10);
-  EXPECT_EQ(INT_MAX, step_size);
+  size_t step_size = GCIdleTimeHandler::EstimateMarkingStepSize(
+      std::numeric_limits<size_t>::max(), 10);
+  EXPECT_EQ(static_cast<size_t>(GCIdleTimeHandler::kMaximumMarkingStepSize),
+            step_size);
 }
 
 }  // namespace internal