Constrain the zone segment pool size

src/zone/accounting-allocator.h

 // Copyright 2016 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_ZONE_ACCOUNTING_ALLOCATOR_H_
 #define V8_ZONE_ACCOUNTING_ALLOCATOR_H_
 
 #include "include/v8-platform.h"
 #include "src/base/atomic-utils.h"
 #include "src/base/atomicops.h"
 #include "src/base/macros.h"
 #include "src/base/platform/mutex.h"
 #include "src/base/platform/semaphore.h"
 #include "src/base/platform/time.h"
 #include "src/zone/zone-segment.h"
 
 namespace v8 {
 namespace internal {
 
 class V8_EXPORT_PRIVATE AccountingAllocator {
  public:
+  static const size_t kMaxPoolSizeLowMemoryDevice = 8ul * KB;
+  static const size_t kMaxPoolSizeMediumMemoryDevice = 1ul * MB;
+  static const size_t kMaxPoolSizeHighMemoryDevice = 2ul * MB;
+  static const size_t kMaxPoolSizeHugeMemoryDevice = 3ul * MB;
+
   AccountingAllocator();
   virtual ~AccountingAllocator();
 
   // Gets an empty segment from the pool or creates a new one.
   virtual Segment* GetSegment(size_t bytes);
   // Return unneeded segments to either insert them into the pool or release
   // them if the pool is already full or memory pressure is high.
   virtual void ReturnSegment(Segment* memory);
 
   size_t GetCurrentMemoryUsage() const;
   size_t GetMaxMemoryUsage() const;
 
   size_t GetCurrentPoolSize() const;
 
   void MemoryPressureNotification(MemoryPressureLevel level);
+  void ConfigureSegmentPool(const size_t max_pool_size);
 
   virtual void ZoneCreation(const Zone* zone) {}
   virtual void ZoneDestruction(const Zone* zone) {}
 
  private:
   static const uint8_t kMinSegmentSizePower = 13;
   static const uint8_t kMaxSegmentSizePower = 18;
-  static const uint8_t kMaxSegmentsPerBucket = 5;
 
   STATIC_ASSERT(kMinSegmentSizePower <= kMaxSegmentSizePower);
 
+  static const uint8_t kNumberBuckets =
+      1 + kMaxSegmentSizePower - kMinSegmentSizePower;
+
   // Allocates a new segment. Returns nullptr on failed allocation.
   Segment* AllocateSegment(size_t bytes);
   void FreeSegment(Segment* memory);
 
   // Returns a segment from the pool of at least the requested size.
   Segment* GetSegmentFromPool(size_t requested_size);
   // Trys to add a segment to the pool. Returns false if the pool is full.
   bool AddSegmentToPool(Segment* segment);
 
   // Empties the pool and puts all its contents onto the garbage stack.
   void ClearPool();
 
-  Segment*
-      unused_segments_heads_[1 + kMaxSegmentSizePower - kMinSegmentSizePower];
+  Segment* unused_segments_heads_[kNumberBuckets];
 
-  size_t unused_segments_sizes[1 + kMaxSegmentSizePower - kMinSegmentSizePower];
+  uint8_t unused_segments_sizes[kNumberBuckets];
+  uint8_t unused_segments_max_sizes[kNumberBuckets];
 
   base::Mutex unused_segments_mutex_;
 
   base::AtomicWord current_memory_usage_ = 0;
   base::AtomicWord max_memory_usage_ = 0;
   base::AtomicWord current_pool_size_ = 0;
 
   base::AtomicValue<MemoryPressureLevel> memory_pressure_level_;
 
   DISALLOW_COPY_AND_ASSIGN(AccountingAllocator);
 };
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_ZONE_ACCOUNTING_ALLOCATOR_H_