Use deadline in IdleNotification.

src/heap/heap.cc

Index: src/heap/heap.cc
diff --git a/src/heap/heap.cc b/src/heap/heap.cc
index 715e7ba300cca4d052c205c72acdd44ca0752e3a..a29992c72ac3dfebe77e0d968b096bc2d3900632 100644
--- a/src/heap/heap.cc
+++ b/src/heap/heap.cc
@@ -4392,10 +4392,17 @@ bool Heap::WorthActivatingIncrementalMarking() {
 
 
 bool Heap::IdleNotification(int idle_time_in_ms) {
-  base::ElapsedTimer timer;
-  timer.Start();
-  isolate()->counters()->gc_idle_time_allotted_in_ms()->AddSample(
-      idle_time_in_ms);
+  return IdleNotification(
+      V8::GetCurrentPlatform()->MonotonicallyIncreasingTime() +
+      (static_cast<double>(idle_time_in_ms) /
+       static_cast<double>(base::Time::kMillisecondsPerSecond)));
+}
+
+
+bool Heap::IdleNotification(double deadline_in_seconds) {
+  double deadline_in_ms =
+      deadline_in_seconds *
+      static_cast<double>(base::Time::kMillisecondsPerSecond);
   HistogramTimerScope idle_notification_scope(
       isolate_->counters()->gc_idle_notification());
 
@@ -4425,11 +4432,16 @@ bool Heap::IdleNotification(int idle_time_in_ms) {
       static_cast<size_t>(
           tracer()->NewSpaceAllocationThroughputInBytesPerMillisecond());
 
+  double idle_time_in_ms =
+      deadline_in_ms -
+      (V8::GetCurrentPlatform()->MonotonicallyIncreasingTime() *
+       static_cast<double>(base::Time::kMillisecondsPerSecond));
   GCIdleTimeAction action =
       gc_idle_time_handler_.Compute(idle_time_in_ms, heap_state);
+  isolate()->counters()->gc_idle_time_allotted_in_ms()->AddSample(
+      static_cast<int>(idle_time_in_ms));
 
   bool result = false;
-  int actual_time_in_ms = 0;
   switch (action.type) {
     case DONE:
       result = true;
@@ -4442,11 +4454,14 @@ bool Heap::IdleNotification(int idle_time_in_ms) {
                                   IncrementalMarking::NO_GC_VIA_STACK_GUARD,
                                   IncrementalMarking::FORCE_MARKING,
                                   IncrementalMarking::DO_NOT_FORCE_COMPLETION);
-      actual_time_in_ms = static_cast<int>(timer.Elapsed().InMilliseconds());
-      int remaining_idle_time_in_ms = idle_time_in_ms - actual_time_in_ms;
-      if (remaining_idle_time_in_ms > 0) {
+      double remaining_idle_time_in_ms =
+          deadline_in_ms -
+          (V8::GetCurrentPlatform()->MonotonicallyIncreasingTime() *
+           static_cast<double>(base::Time::kMillisecondsPerSecond));

[rmcilroy, 2014/11/26 11:35:41]

nit - would be good to have a helper for MonotonicallyIncreasingTimeInMs() (in
Platform?) instead of doing this each time.

[Hannes Payer (out of office), 2014/11/27 12:19:15]

Done.

+      if (remaining_idle_time_in_ms > 0.0) {
         TryFinalizeIdleIncrementalMarking(
-            remaining_idle_time_in_ms, heap_state.size_of_objects,
+            static_cast<size_t>(remaining_idle_time_in_ms),
+            heap_state.size_of_objects,
             heap_state.final_incremental_mark_compact_speed_in_bytes_per_ms);
       }
       break;
@@ -4472,20 +4487,26 @@ bool Heap::IdleNotification(int idle_time_in_ms) {
       break;
   }
 
-  actual_time_in_ms = static_cast<int>(timer.Elapsed().InMilliseconds());
-  if (actual_time_in_ms <= idle_time_in_ms) {
+
+  double deadline_difference =
+      deadline_in_ms -
+      (V8::GetCurrentPlatform()->MonotonicallyIncreasingTime() *
+       static_cast<double>(base::Time::kMillisecondsPerSecond));
+  if (deadline_difference >= 0) {
     if (action.type != DONE && action.type != DO_NOTHING) {
       isolate()->counters()->gc_idle_time_limit_undershot()->AddSample(
-          idle_time_in_ms - actual_time_in_ms);
+          static_cast<int>(deadline_difference));
     }
   } else {
     isolate()->counters()->gc_idle_time_limit_overshot()->AddSample(
-        actual_time_in_ms - idle_time_in_ms);
+        static_cast<int>(-deadline_difference));
   }
 
   if (FLAG_trace_idle_notification) {
-    PrintF("Idle notification: requested idle time %d ms, actual time %d ms [",
-           idle_time_in_ms, actual_time_in_ms);
+    PrintF(
+        "Idle notification: requested idle time %.2f ms, deadline difference "
+        "%.2f ms [",
+        idle_time_in_ms, deadline_difference);
     action.Print();
     PrintF("]");
     if (FLAG_trace_idle_notification_verbose) {