Updating trunk VERSION from 2139.0 to 2140.0
[chromium-blink-merge.git] / base / memory / discardable_memory_emulated.h
blobd928513527ea895f1e44ebd3a0415bfe446e3319
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.
5 #ifndef BASE_MEMORY_DISCARDABLE_MEMORY_EMULATED_H_
6 #define BASE_MEMORY_DISCARDABLE_MEMORY_EMULATED_H_
8 #include "base/memory/discardable_memory.h"
10 #include "base/memory/discardable_memory_manager.h"
12 namespace base {
13 namespace internal {
15 class DiscardableMemoryEmulated
16 : public DiscardableMemory,
17 public internal::DiscardableMemoryManagerAllocation {
18 public:
19 explicit DiscardableMemoryEmulated(size_t bytes);
20 virtual ~DiscardableMemoryEmulated();
22 static bool ReduceMemoryUsage();
24 // TODO(reveman): Remove this as it is breaking the discardable memory design
25 // principle that implementations should not rely on information this is
26 // unavailable in kernel space. crbug.com/400423
27 BASE_EXPORT static void ReduceMemoryUsageUntilWithinLimit(size_t bytes);
29 static void PurgeForTesting();
31 bool Initialize();
33 // Overridden from DiscardableMemory:
34 virtual DiscardableMemoryLockStatus Lock() OVERRIDE;
35 virtual void Unlock() OVERRIDE;
36 virtual void* Memory() const OVERRIDE;
38 // Overridden from internal::DiscardableMemoryManagerAllocation:
39 virtual bool AllocateAndAcquireLock() OVERRIDE;
40 virtual void ReleaseLock() OVERRIDE {}
41 virtual void Purge() OVERRIDE;
43 private:
44 const size_t bytes_;
45 scoped_ptr<uint8[]> memory_;
46 bool is_locked_;
48 DISALLOW_COPY_AND_ASSIGN(DiscardableMemoryEmulated);
51 } // namespace internal
52 } // namespace base
54 #endif // BASE_MEMORY_DISCARDABLE_MEMORY_EMULATED_H_