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/discardable_shared_memory_heap.h"
  13
  14 namespace content {
  15
  16 // Implementation of DiscardableMemoryShmemAllocator that allocates
  17 // discardable memory segments through the browser process.
  18 class ChildDiscardableSharedMemoryManager
  19     : public base::DiscardableMemoryShmemAllocator {
  20  public:
  21   explicit ChildDiscardableSharedMemoryManager(ThreadSafeSender* sender);
  22   ~ChildDiscardableSharedMemoryManager() override;
  23
  24   // Overridden from base::DiscardableMemoryShmemAllocator:
  25   scoped_ptr<base::DiscardableMemoryShmemChunk> AllocateLockedDiscardableMemory(
  26       size_t size) override;
  27
  28   bool LockSpan(DiscardableSharedMemoryHeap::Span* span);
  29   void UnlockSpan(DiscardableSharedMemoryHeap::Span* span);
  30   bool IsSpanResident(DiscardableSharedMemoryHeap::Span* span) const;
  31   void ReleaseSpan(scoped_ptr<DiscardableSharedMemoryHeap::Span> span);
  32
  33  private:
  34   scoped_ptr<base::DiscardableSharedMemory>
  35   AllocateLockedDiscardableSharedMemory(size_t size);
  36
  37   mutable base::Lock lock_;
  38   DiscardableSharedMemoryHeap heap_;
  39   scoped_refptr<ThreadSafeSender> sender_;
  40
  41   DISALLOW_COPY_AND_ASSIGN(ChildDiscardableSharedMemoryManager);
  42 };
  43
  44 }  // namespace content
  45
  46 #endif  // CONTENT_CHILD_CHILD_DISCARDABLE_SHARED_MEMORY_MANAGER_H_