base/memory/discardable_memory_shmem.h

   1 // Copyright 2014 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_SHMEM_H_
   6 #define BASE_MEMORY_DISCARDABLE_MEMORY_SHMEM_H_
   7
   8 #include "base/memory/discardable_memory.h"
   9
  10 #include "base/memory/discardable_memory_manager.h"
  11
  12 namespace base {
  13 class DiscardableMemoryShmemChunk;
  14
  15 namespace internal {
  16
  17 class DiscardableMemoryShmem
  18     : public DiscardableMemory,
  19       public internal::DiscardableMemoryManagerAllocation {
  20  public:
  21   explicit DiscardableMemoryShmem(size_t bytes);
  22   ~DiscardableMemoryShmem() override;
  23
  24   static void ReleaseFreeMemory();
  25
  26   static void PurgeForTesting();
  27
  28   bool Initialize();
  29
  30   // Overridden from DiscardableMemory:
  31   DiscardableMemoryLockStatus Lock() override;
  32   void Unlock() override;
  33   void* Memory() const override;
  34
  35   // Overridden from internal::DiscardableMemoryManagerAllocation:
  36   bool AllocateAndAcquireLock() override;
  37   void ReleaseLock() override;
  38   void Purge() override;
  39   bool IsMemoryResident() const override;
  40
  41  private:
  42   const size_t bytes_;
  43   scoped_ptr<DiscardableMemoryShmemChunk> chunk_;
  44   bool is_locked_;
  45
  46   DISALLOW_COPY_AND_ASSIGN(DiscardableMemoryShmem);
  47 };
  48
  49 }  // namespace internal
  50 }  // namespace base
  51
  52 #endif  // BASE_MEMORY_DISCARDABLE_MEMORY_SHMEM_H_