base/memory/discardable_memory_emulated.h

   1 // Copyright 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef BASE_MEMORY_DISCARDABLE_MEMORY_EMULATED_H_
   6 #define BASE_MEMORY_DISCARDABLE_MEMORY_EMULATED_H_
   7
   8 #include "base/memory/discardable_memory.h"
   9
  10 #include "base/memory/discardable_memory_manager.h"
  11
  12 namespace base {
  13 namespace internal {
  14
  15 class DiscardableMemoryEmulated
  16     : public DiscardableMemory,
  17       public internal::DiscardableMemoryManagerAllocation {
  18  public:
  19   explicit DiscardableMemoryEmulated(size_t bytes);
  20   virtual ~DiscardableMemoryEmulated();
  21
  22   static void RegisterMemoryPressureListeners();
  23   static void UnregisterMemoryPressureListeners();
  24
  25   static void PurgeForTesting();
  26
  27   bool Initialize();
  28
  29   // Overridden from DiscardableMemory:
  30   virtual DiscardableMemoryLockStatus Lock() OVERRIDE;
  31   virtual void Unlock() OVERRIDE;
  32   virtual void* Memory() const OVERRIDE;
  33
  34   // Overridden from internal::DiscardableMemoryManagerAllocation:
  35   virtual bool AllocateAndAcquireLock() OVERRIDE;
  36   virtual void ReleaseLock() OVERRIDE {}
  37   virtual void Purge() OVERRIDE;
  38
  39  private:
  40   const size_t bytes_;
  41   scoped_ptr<uint8[]> memory_;
  42   bool is_locked_;
  43
  44   DISALLOW_COPY_AND_ASSIGN(DiscardableMemoryEmulated);
  45 };
  46
  47 }  // namespace internal
  48 }  // namespace base
  49
  50 #endif  // BASE_MEMORY_DISCARDABLE_MEMORY_EMULATED_H_