[heap] Fix scavenger --trace-gc-nvp glitches.

src/heap/gc-tracer.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 "src/heap/gc-tracer.h"
 
 #include "src/counters.h"
 #include "src/heap/heap-inl.h"
 #include "src/isolate.h"
 
@@ skipping 317 matching lines @@
   old_generation_allocation_counter_bytes_ = old_generation_counter_bytes;
   allocation_duration_since_gc_ += duration;
   new_space_allocation_in_bytes_since_gc_ += new_space_allocated_bytes;
   old_generation_allocation_in_bytes_since_gc_ +=
       old_generation_allocated_bytes;
 }
 
 
 void GCTracer::AddAllocation(double current_ms) {
   allocation_time_ms_ = current_ms;
-  new_space_allocation_events_.push_front(AllocationEvent(
-      allocation_duration_since_gc_, new_space_allocation_in_bytes_since_gc_));
-  old_generation_allocation_events_.push_front(
-      AllocationEvent(allocation_duration_since_gc_,
-                      old_generation_allocation_in_bytes_since_gc_));
+  if (allocation_duration_since_gc_ > 0) {
+    new_space_allocation_events_.push_front(
+        AllocationEvent(allocation_duration_since_gc_,
+                        new_space_allocation_in_bytes_since_gc_));
+    old_generation_allocation_events_.push_front(
+        AllocationEvent(allocation_duration_since_gc_,
+                        old_generation_allocation_in_bytes_since_gc_));
+  }
   allocation_duration_since_gc_ = 0;
   new_space_allocation_in_bytes_since_gc_ = 0;
   old_generation_allocation_in_bytes_since_gc_ = 0;
 }
 
 
 void GCTracer::AddContextDisposalTime(double time) {
   context_disposal_events_.push_front(ContextDisposalEvent(time));
 }
 
@@ skipping 109 matching lines @@
                    "mutator=%.1f "
                    "gc=%s "
                    "reduce_memory=%d "
                    "scavenge=%.2f "
                    "old_new=%.2f "
                    "weak=%.2f "
                    "roots=%.2f "
                    "code=%.2f "
                    "semispace=%.2f "
                    "object_groups=%.2f "
-                   "external_prologue=$.2f "
-                   "external_epilogue=$.2f "
-                   "external_weak_global_handles=$.2f "
+                   "external_prologue=%.2f "
+                   "external_epilogue=%.2f "
+                   "external_weak_global_handles=%.2f "
                    "steps_count=%d "
                    "steps_took=%.1f "
                    "scavenge_throughput=%" V8_PTR_PREFIX
                    "d "
                    "total_size_before=%" V8_PTR_PREFIX
                    "d "
                    "total_size_after=%" V8_PTR_PREFIX
                    "d "
                    "holes_size_before=%" V8_PTR_PREFIX
                    "d "
                    "holes_size_after=%" V8_PTR_PREFIX
                    "d "
                    "allocated=%" V8_PTR_PREFIX
                    "d "
                    "promoted=%" V8_PTR_PREFIX
                    "d "
                    "semi_space_copied=%" V8_PTR_PREFIX
                    "d "
                    "nodes_died_in_new=%d "
                    "nodes_copied_in_new=%d "
                    "nodes_promoted=%d "
                    "promotion_ratio=%.1f%% "
                    "average_survival_ratio=%.1f%% "
                    "promotion_rate=%.1f%% "
                    "semi_space_copy_rate=%.1f%% "
-                   "new_space_allocation_throughput=%" V8_PTR_PREFIX
-                   "d "
+                   "new_space_allocation_throughput=%.1f "
                    "context_disposal_rate=%.1f\n",
                    heap_->isolate()->time_millis_since_init(), duration,
                    spent_in_mutator, current_.TypeName(true),
                    current_.reduce_memory,
                    current_.scopes[Scope::SCAVENGER_SCAVENGE],
                    current_.scopes[Scope::SCAVENGER_OLD_TO_NEW_POINTERS],
                    current_.scopes[Scope::SCAVENGER_WEAK],
                    current_.scopes[Scope::SCAVENGER_ROOTS],
                    current_.scopes[Scope::SCAVENGER_CODE_FLUSH_CANDIDATES],
                    current_.scopes[Scope::SCAVENGER_SEMISPACE],
@@ skipping 82 matching lines @@
           "d "
           "semi_space_copied=%" V8_PTR_PREFIX
           "d "
           "nodes_died_in_new=%d "
           "nodes_copied_in_new=%d "
           "nodes_promoted=%d "
           "promotion_ratio=%.1f%% "
           "average_survival_ratio=%.1f%% "
           "promotion_rate=%.1f%% "
           "semi_space_copy_rate=%.1f%% "
-          "new_space_allocation_throughput=%" V8_PTR_PREFIX
-          "d "
+          "new_space_allocation_throughput=%.1f "
           "context_disposal_rate=%.1f "
           "compaction_speed=%" V8_PTR_PREFIX "d\n",
           heap_->isolate()->time_millis_since_init(), duration,
           spent_in_mutator, current_.TypeName(true), current_.reduce_memory,
           current_.scopes[Scope::MC_CLEAR],
           current_.scopes[Scope::MC_CLEAR_CODE_FLUSH],
           current_.scopes[Scope::MC_CLEAR_DEPENDENT_CODE],
           current_.scopes[Scope::MC_CLEAR_GLOBAL_HANDLES],
           current_.scopes[Scope::MC_CLEAR_MAPS],
           current_.scopes[Scope::MC_CLEAR_SLOTS_BUFFER],
@@ skipping 188 matching lines @@
     combined_mark_compact_speed_cache_ =
         static_cast<double>(MarkCompactSpeedInBytesPerMillisecond());
   } else {
     // Combine the speed of incremental step and the speed of the final step.
     // 1 / (1 / speed1 + 1 / speed2) = speed1 * speed2 / (speed1 + speed2).
     combined_mark_compact_speed_cache_ = speed1 * speed2 / (speed1 + speed2);
   }
   return combined_mark_compact_speed_cache_;
 }
 
-
-size_t GCTracer::NewSpaceAllocationThroughputInBytesPerMillisecond(
+double GCTracer::NewSpaceAllocationThroughputInBytesPerMillisecond(
     double time_ms) const {
   size_t bytes = new_space_allocation_in_bytes_since_gc_;
   double durations = allocation_duration_since_gc_;
   AllocationEventBuffer::const_iterator iter =
       new_space_allocation_events_.begin();
   const size_t max_bytes = static_cast<size_t>(-1);
   while (iter != new_space_allocation_events_.end() &&
          bytes < max_bytes - bytes && (time_ms == 0 || durations < time_ms)) {
     bytes += iter->allocation_in_bytes_;
     durations += iter->duration_;
     ++iter;
   }
 
   if (durations == 0.0) return 0;
+
   // Make sure the result is at least 1.
-  return Max<size_t>(static_cast<size_t>(bytes / durations + 0.5), 1);
+  return Max<double>(bytes / durations, 1);
 }
 
-
-size_t GCTracer::OldGenerationAllocationThroughputInBytesPerMillisecond(
+double GCTracer::OldGenerationAllocationThroughputInBytesPerMillisecond(
     double time_ms) const {
   size_t bytes = old_generation_allocation_in_bytes_since_gc_;
   double durations = allocation_duration_since_gc_;
   AllocationEventBuffer::const_iterator iter =
       old_generation_allocation_events_.begin();
   const size_t max_bytes = static_cast<size_t>(-1);
   while (iter != old_generation_allocation_events_.end() &&
          bytes < max_bytes - bytes && (time_ms == 0 || durations < time_ms)) {
     bytes += iter->allocation_in_bytes_;
     durations += iter->duration_;
     ++iter;
   }
 
   if (durations == 0.0) return 0;
   // Make sure the result is at least 1.
-  return Max<size_t>(static_cast<size_t>(bytes / durations + 0.5), 1);
+  return Max<double>(bytes / durations, 1);
 }
 
-
-size_t GCTracer::AllocationThroughputInBytesPerMillisecond(
+double GCTracer::AllocationThroughputInBytesPerMillisecond(
     double time_ms) const {
   return NewSpaceAllocationThroughputInBytesPerMillisecond(time_ms) +
          OldGenerationAllocationThroughputInBytesPerMillisecond(time_ms);
 }
 
 
 size_t GCTracer::CurrentAllocationThroughputInBytesPerMillisecond() const {
   return AllocationThroughputInBytesPerMillisecond(kThroughputTimeFrameMs);
 }
 
@@ skipping 36 matching lines @@
 
 
 bool GCTracer::SurvivalEventsRecorded() const {
   return survival_events_.size() > 0;
 }
 
 
 void GCTracer::ResetSurvivalEvents() { survival_events_.reset(); }
 }  // namespace internal
 }  // namespace v8