content/browser/memory/memory_monitor_android.h

// Copyright 2016 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.

#ifndef CONTENT_BROWSER_MEMORY_MEMORY_MONITOR_ANDROID_H_
#define CONTENT_BROWSER_MEMORY_MEMORY_MONITOR_ANDROID_H_

#include <jni.h>

#include "base/android/application_status_listener.h"
#include "content/browser/memory/memory_monitor.h"

namespace content {

// A memory monitor for the Android system.
class CONTENT_EXPORT MemoryMonitorAndroid : public MemoryMonitor {
 public:
  static std::unique_ptr<MemoryMonitorAndroid> Create();

  // C++ counter-part of ActivityManager.MemoryInfo
  struct MemoryInfo {
    jlong avail_mem;
    jboolean low_memory;
    jlong threshold;
    jlong total_mem;
  };

  // Delegate interface used by MemoryMonitorAndroid.
  class Delegate {
   public:
    Delegate() {}
    virtual ~Delegate() {};

    // Get MemoryInfo. Implementations should fill |out| accordingly.
    virtual void GetMemoryInfo(MemoryInfo* out) = 0;
  };

  MemoryMonitorAndroid(std::unique_ptr<Delegate> delegate);
  ~MemoryMonitorAndroid() override;

  // MemoryMonitor implementation:
  int GetFreeMemoryUntilCriticalMB() override;

  // Get memory info from the Android system.
  void GetMemoryInfo(MemoryInfo* out);

  Delegate* delegate() { return delegate_.get(); }

 private:
  void OnApplicationStateChange(base::android::ApplicationState state);

  std::unique_ptr<Delegate> delegate_;
  std::unique_ptr<base::android::ApplicationStatusListener>
      application_state_listener_;

  DISALLOW_COPY_AND_ASSIGN(MemoryMonitorAndroid);
};

}  // namespace content

#endif  // CONTENT_BROWSER_MEMORY_MEMORY_MONITOR_ANDROID_H_