blob: 468a7eeef7d275cd5b0f8899a055d3950d3081e6 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
|
// Copyright 2014 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 ATHENA_RESOURCE_MANAGER_MEMORY_PRESSURE_NOTIFIER_H_
#define ATHENA_RESOURCE_MANAGER_MEMORY_PRESSURE_NOTIFIER_H_
#include "athena/athena_export.h"
#include "athena/resource_manager/public/resource_manager.h"
#include "base/memory/ref_counted.h"
#include "base/memory/scoped_ptr.h"
#include "base/timer/timer.h"
namespace athena {
class MemoryPressureNotifierImpl;
class ResourceManagerDelegate;
////////////////////////////////////////////////////////////////////////////////
// MemoryPressureObserver
//
// This observer gets informed once about a |MEMORY_PRESSURE_LOW|. When the
// pressure exceeds, the observer will get polled until |MEMORY_PRESSURE_LOW| is
// reached again to counter memory consumption.
class MemoryPressureObserver {
public:
MemoryPressureObserver() {}
virtual ~MemoryPressureObserver() {}
// The observer.
virtual void OnMemoryPressure(ResourceManager::MemoryPressure pressure) = 0;
// OS system interface functions. The delegate remains owned by the Observer.
virtual ResourceManagerDelegate* GetDelegate() = 0;
};
////////////////////////////////////////////////////////////////////////////////
// MemoryPressureNotifier
//
// Class to handle the observation of our free memory. It notifies the owner of
// memory fill level changes, so that it can take action to reduce memory by
// reducing active activities.
//
// The observer will use 3 different fill levels: 50% full, 75% full and 90%
// full.
class ATHENA_EXPORT MemoryPressureNotifier {
public:
// The creator gets the |listener| object. Note that the ownership of the
// listener object remains with the creator.
explicit MemoryPressureNotifier(MemoryPressureObserver* listener);
~MemoryPressureNotifier();
// Stop observing the memory fill level.
// May be safely called if StartObserving has not been called.
void StopObserving();
private:
// Starts observing the memory fill level.
// Calls to StartObserving should always be matched with calls to
// StopObserving.
void StartObserving();
// The function which gets periodically be called to check any changes in the
// memory pressure.
void CheckMemoryPressure();
// Converts free percent of memory into a memory pressure value.
ResourceManager::MemoryPressure GetMemoryPressureLevelFromFillLevel(
int memory_fill_level);
base::RepeatingTimer<MemoryPressureNotifier> timer_;
// The listener which needs to be informed about memory pressure.
MemoryPressureObserver* listener_;
// Our current memory pressure.
ResourceManager::MemoryPressure current_pressure_;
DISALLOW_COPY_AND_ASSIGN(MemoryPressureNotifier);
};
} // namespace athena
#endif // ATHENA_RESOURCE_MANAGER_MEMORY_PRESSURE_NOTIFIER_H_
|
