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/synchronization/lock.h"
  11 #include "base/trace_event/memory_dump_provider.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 base::trace_event::MemoryDumpProvider {
  24  public:
  25   explicit ChildDiscardableSharedMemoryManager(ThreadSafeSender* sender);
  26   ~ChildDiscardableSharedMemoryManager() override;
  27
  28   // Overridden from base::DiscardableMemoryAllocator:
  29   scoped_ptr<base::DiscardableMemory> AllocateLockedDiscardableMemory(
  30       size_t size) override;
  31
  32   // Overridden from base::trace_event::MemoryDumpProvider:
  33   bool OnMemoryDump(base::trace_event::ProcessMemoryDump* pmd) override;
  34
  35   // Release memory and associated resources that have been purged.
  36   void ReleaseFreeMemory();
  37
  38   bool LockSpan(DiscardableSharedMemoryHeap::Span* span);
  39   void UnlockSpan(DiscardableSharedMemoryHeap::Span* span);
  40   void ReleaseSpan(scoped_ptr<DiscardableSharedMemoryHeap::Span> span);
  41
  42  private:
  43   scoped_ptr<base::DiscardableSharedMemory>
  44   AllocateLockedDiscardableSharedMemory(size_t size,
  45                                         DiscardableSharedMemoryId id);
  46   void MemoryUsageChanged(size_t new_bytes_allocated,
  47                           size_t new_bytes_free) const;
  48
  49   mutable base::Lock lock_;
  50   DiscardableSharedMemoryHeap heap_;
  51   scoped_refptr<ThreadSafeSender> sender_;
  52
  53   DISALLOW_COPY_AND_ASSIGN(ChildDiscardableSharedMemoryManager);
  54 };
  55
  56 }  // namespace content
  57
  58 #endif  // CONTENT_CHILD_CHILD_DISCARDABLE_SHARED_MEMORY_MANAGER_H_