Shrink new space on compacting collections.

src/heap.cc

 // Copyright 2009 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 447 matching lines @@
   EnsureFromSpaceIsCommitted();
   if (collector == MARK_COMPACTOR) {
     MarkCompact(tracer);
 
     int old_gen_size = PromotedSpaceSize();
     old_gen_promotion_limit_ =
         old_gen_size + Max(kMinimumPromotionLimit, old_gen_size / 3);
     old_gen_allocation_limit_ =
         old_gen_size + Max(kMinimumAllocationLimit, old_gen_size / 2);
     old_gen_exhausted_ = false;
+  } else {
+    Scavenge();
   }
-  Scavenge();
   Counters::objs_since_last_young.Set(0);
 
   PostGarbageCollectionProcessing();
 
   if (collector == MARK_COMPACTOR) {
     // Register the amount of external allocated memory.
     amount_of_external_allocated_memory_at_last_global_gc_ =
         amount_of_external_allocated_memory_;
   }
 
@@ skipping 33 matching lines @@
   MarkCompactEpilogue(is_compacting);
 
   LOG(ResourceEvent("markcompact", "end"));
 
   gc_state_ = NOT_IN_GC;
 
   Shrink();
 
   Counters::objs_since_last_full.Set(0);
   context_disposed_pending_ = false;
+
+  Scavenge();
+
+  // Shrink new space as much as possible after compacting full
+  // garbage collections.
+  if (is_compacting) new_space_.Shrink();
 }
 
 
 void Heap::MarkCompactPrologue(bool is_compacting) {
   // At any old GC clear the keyed lookup cache to enable collection of unused
   // maps.
   KeyedLookupCache::Clear();
   ContextSlotCache::Clear();
   DescriptorLookupCache::Clear();
 
@@ skipping 128 matching lines @@
   // Clear descriptor cache.
   DescriptorLookupCache::Clear();
 
   // Used for updating survived_since_last_expansion_ at function end.
   int survived_watermark = PromotedSpaceSize();
 
   if (new_space_.Capacity() < new_space_.MaximumCapacity() &&
       survived_since_last_expansion_ > new_space_.Capacity()) {
     // Grow the size of new space if there is room to grow and enough
     // data has survived scavenge since the last expansion.
-    // TODO(1240712): NewSpace::Grow has a return value which is
-    // ignored here.
     new_space_.Grow();
     survived_since_last_expansion_ = 0;
   }
 
   // Flip the semispaces.  After flipping, to space is empty, from space has
   // live objects.
   new_space_.Flip();
   new_space_.ResetAllocationInfo();
 
   // We need to sweep newly copied objects which can be either in the
@@ skipping 3238 matching lines @@
 #ifdef DEBUG
 bool Heap::GarbageCollectionGreedyCheck() {
   ASSERT(FLAG_gc_greedy);
   if (Bootstrapper::IsActive()) return true;
   if (disallow_allocation_failure()) return true;
   return CollectGarbage(0, NEW_SPACE);
 }
 #endif
 
 } }  // namespace v8::internal