| // Copyright 2013 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #include "base/memory/discardable_memory.h" |
| |
| #include "base/memory/discardable_memory_provider.h" |
| |
| using base::internal::DiscardableMemoryProvider; |
| |
| namespace base { |
| namespace { |
| |
| class DiscardableMemoryEmulated : public DiscardableMemory { |
| public: |
| explicit DiscardableMemoryEmulated(size_t size) : is_locked_(false) { |
| DiscardableMemoryProvider::GetInstance()->Register(this, size); |
| } |
| |
| virtual ~DiscardableMemoryEmulated() { |
| if (is_locked_) |
| Unlock(); |
| DiscardableMemoryProvider::GetInstance()->Unregister(this); |
| } |
| |
| // DiscardableMemory: |
| virtual LockDiscardableMemoryStatus Lock() OVERRIDE { |
| DCHECK(!is_locked_); |
| |
| bool purged = false; |
| memory_ = DiscardableMemoryProvider::GetInstance()->Acquire(this, &purged); |
| if (!memory_) |
| return DISCARDABLE_MEMORY_FAILED; |
| |
| is_locked_ = true; |
| return purged ? DISCARDABLE_MEMORY_PURGED : DISCARDABLE_MEMORY_SUCCESS; |
| } |
| |
| virtual void Unlock() OVERRIDE { |
| DCHECK(is_locked_); |
| DiscardableMemoryProvider::GetInstance()->Release(this, memory_.Pass()); |
| is_locked_ = false; |
| } |
| |
| virtual void* Memory() const OVERRIDE { |
| DCHECK(memory_); |
| return memory_.get(); |
| } |
| |
| private: |
| scoped_ptr<uint8, FreeDeleter> memory_; |
| bool is_locked_; |
| |
| DISALLOW_COPY_AND_ASSIGN(DiscardableMemoryEmulated); |
| }; |
| |
| } // namespace |
| |
| // static |
| bool DiscardableMemory::SupportedNatively() { |
| return false; |
| } |
| |
| // static |
| scoped_ptr<DiscardableMemory> DiscardableMemory::CreateLockedMemory( |
| size_t size) { |
| scoped_ptr<DiscardableMemory> memory(new DiscardableMemoryEmulated(size)); |
| if (!memory) |
| return scoped_ptr<DiscardableMemory>(); |
| if (memory->Lock() != DISCARDABLE_MEMORY_PURGED) |
| return scoped_ptr<DiscardableMemory>(); |
| return memory.Pass(); |
| } |
| |
| // static |
| bool DiscardableMemory::PurgeForTestingSupported() { |
| return true; |
| } |
| |
| // static |
| void DiscardableMemory::PurgeForTesting() { |
| DiscardableMemoryProvider::GetInstance()->PurgeAll(); |
| } |
| |
| } // namespace base |