content/child/child_discardable_shared_memory_manager.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 CONTENT_CHILD_CHILD_DISCARDABLE_SHARED_MEMORY_MANAGER_H_
   6 #define CONTENT_CHILD_CHILD_DISCARDABLE_SHARED_MEMORY_MANAGER_H_
   7
   8 #include "base/memory/discardable_memory_shmem_allocator.h"
   9 #include "base/memory/ref_counted.h"
  10 #include "base/synchronization/lock.h"
  11 #include "content/child/thread_safe_sender.h"
  12 #include "content/common/content_export.h"
  13 #include "content/common/discardable_shared_memory_heap.h"
  14
  15 namespace content {
  16
  17 // Implementation of DiscardableMemoryShmemAllocator that allocates
  18 // discardable memory segments through the browser process.
  19 class CONTENT_EXPORT ChildDiscardableSharedMemoryManager
  20     : public base::DiscardableMemoryShmemAllocator {
  21  public:
  22   explicit ChildDiscardableSharedMemoryManager(ThreadSafeSender* sender);
  23   ~ChildDiscardableSharedMemoryManager() override;
  24
  25   // Overridden from base::DiscardableMemoryShmemAllocator:
  26   scoped_ptr<base::DiscardableMemoryShmemChunk> AllocateLockedDiscardableMemory(
  27       size_t size) override;
  28
  29   // Release memory and associated resources that have been purged.
  30   void ReleaseFreeMemory();
  31
  32   bool LockSpan(DiscardableSharedMemoryHeap::Span* span);
  33   void UnlockSpan(DiscardableSharedMemoryHeap::Span* span);
  34   void ReleaseSpan(scoped_ptr<DiscardableSharedMemoryHeap::Span> span);
  35
  36  private:
  37   scoped_ptr<base::DiscardableSharedMemory>
  38   AllocateLockedDiscardableSharedMemory(size_t size);
  39
  40   mutable base::Lock lock_;
  41   DiscardableSharedMemoryHeap heap_;
  42   scoped_refptr<ThreadSafeSender> sender_;
  43
  44   DISALLOW_COPY_AND_ASSIGN(ChildDiscardableSharedMemoryManager);
  45 };
  46
  47 }  // namespace content
  48
  49 #endif  // CONTENT_CHILD_CHILD_DISCARDABLE_SHARED_MEMORY_MANAGER_H_