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_allocator.h"
   9 #include "base/memory/ref_counted.h"
  10 #include "base/memory/weak_ptr.h"
  11 #include "base/synchronization/lock.h"
  12 #include "content/child/thread_safe_sender.h"
  13 #include "content/common/content_export.h"
  14 #include "content/common/discardable_shared_memory_heap.h"
  15 #include "content/common/host_discardable_shared_memory_manager.h"
  16
  17 namespace content {
  18
  19 // Implementation of DiscardableMemoryAllocator that allocates
  20 // discardable memory segments through the browser process.
  21 class CONTENT_EXPORT ChildDiscardableSharedMemoryManager
  22     : public base::DiscardableMemoryAllocator {
  23  public:
  24   explicit ChildDiscardableSharedMemoryManager(ThreadSafeSender* sender);
  25   ~ChildDiscardableSharedMemoryManager() override;
  26
  27   // Overridden from base::DiscardableMemoryAllocator:
  28   scoped_ptr<base::DiscardableMemory> AllocateLockedDiscardableMemory(
  29       size_t size) override;
  30
  31   // Release memory and associated resources that have been purged.
  32   void ReleaseFreeMemory();
  33
  34   bool LockSpan(DiscardableSharedMemoryHeap::Span* span);
  35   void UnlockSpan(DiscardableSharedMemoryHeap::Span* span);
  36   void ReleaseSpan(scoped_ptr<DiscardableSharedMemoryHeap::Span> span);
  37
  38  private:
  39   scoped_ptr<base::DiscardableSharedMemory>
  40   AllocateLockedDiscardableSharedMemory(size_t size,
  41                                         DiscardableSharedMemoryId id);
  42   void DeletedDiscardableSharedMemory(DiscardableSharedMemoryId id);
  43   void MemoryUsageChanged(size_t new_bytes_allocated,
  44                           size_t new_bytes_free) const;
  45
  46   mutable base::Lock lock_;
  47   DiscardableSharedMemoryHeap heap_;
  48   scoped_refptr<ThreadSafeSender> sender_;
  49   base::WeakPtrFactory<ChildDiscardableSharedMemoryManager> weak_ptr_factory_;
  50
  51   DISALLOW_COPY_AND_ASSIGN(ChildDiscardableSharedMemoryManager);
  52 };
  53
  54 }  // namespace content
  55
  56 #endif  // CONTENT_CHILD_CHILD_DISCARDABLE_SHARED_MEMORY_MANAGER_H_