Unify memory optimization modes and flags.

src/heap/heap.h

 // Copyright 2012 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.
 
 #ifndef V8_HEAP_HEAP_H_
 #define V8_HEAP_HEAP_H_
 
 #include <cmath>
 #include <map>
 
@@ skipping 545 matching lines @@
   static const int kMaxExecutableSizeHugeMemoryDevice =
       256 * kPointerMultiplier;
 
   static const int kTraceRingBufferSize = 512;
   static const int kStacktraceBufferSize = 512;
 
   static const double kMinHeapGrowingFactor;
   static const double kMaxHeapGrowingFactor;
   static const double kMaxHeapGrowingFactorMemoryConstrained;
   static const double kMaxHeapGrowingFactorIdle;
+  static const double kConservativeHeapGrowingFactor;
   static const double kTargetMutatorUtilization;
 
   static const int kNoGCFlags = 0;
   static const int kReduceMemoryFootprintMask = 1;
   static const int kAbortIncrementalMarkingMask = 2;
   static const int kFinalizeIncrementalMarkingMask = 4;
 
   // Making the heap iterable requires us to abort incremental marking.
   static const int kMakeHeapIterableMask = kAbortIncrementalMarkingMask;
 
@@ skipping 305 matching lines @@
   // This event is triggered after object is moved to a new place.
   inline void OnMoveEvent(HeapObject* target, HeapObject* source,
                           int size_in_bytes);
 
   bool deserialization_complete() const { return deserialization_complete_; }
 
   bool HasLowAllocationRate();
   bool HasHighFragmentation();
   bool HasHighFragmentation(intptr_t used, intptr_t committed);
 
-  void SetOptimizeForLatency() { optimize_for_memory_usage_ = false; }
-  void SetOptimizeForMemoryUsage();
-  bool ShouldOptimizeForMemoryUsage() {
-    return optimize_for_memory_usage_ || HighMemoryPressure();
+  void ActivateMemoryReducerIfNeeded();
+
+  bool ShouldOptimizeForMemoryUsage();
+
+  bool IsLowMemoryDevice() {
+    return max_old_generation_size_ <= kMaxOldSpaceSizeLowMemoryDevice;
   }
+
+  bool IsMemoryConstrainedDevice() {
+    return max_old_generation_size_ <= kMaxOldSpaceSizeMediumMemoryDevice;
+  }
+
   bool HighMemoryPressure() {
     return memory_pressure_level_.Value() != MemoryPressureLevel::kNone;
   }
 
   // ===========================================================================
   // Initialization. ===========================================================
   // ===========================================================================
 
   // Configure heap size in MB before setup. Return false if the heap has been
   // set up already.
@@ skipping 1206 matching lines @@
   // Limit that triggers a global GC on the next (normally caused) GC.  This
   // is checked when we have already decided to do a GC to help determine
   // which collector to invoke, before expanding a paged space in the old
   // generation and on every allocation in large object space.
   intptr_t old_generation_allocation_limit_;
 
   // Indicates that an allocation has failed in the old generation since the
   // last GC.
   bool old_gen_exhausted_;
 
-  // Indicates that memory usage is more important than latency.
-  // TODO(ulan): Merge it with memory reducer once chromium:490559 is fixed.
-  bool optimize_for_memory_usage_;
-
   // Indicates that inline bump-pointer allocation has been globally disabled
   // for all spaces. This is used to disable allocations in generated code.
   bool inline_allocation_disabled_;
 
   // Weak list heads, threaded through the objects.
   // List heads are initialized lazily and contain the undefined_value at start.
   Object* native_contexts_list_;
   Object* allocation_sites_list_;
 
   // List of encountered weak collections (JSWeakMap and JSWeakSet) during
@@ skipping 562 matching lines @@
   friend class LargeObjectSpace;
   friend class NewSpace;
   friend class PagedSpace;
   DISALLOW_COPY_AND_ASSIGN(AllocationObserver);
 };
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_HEAP_HEAP_H_