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
|
// Copyright 2019 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef COMPONENTS_MEMORY_PRESSURE_SYSTEM_MEMORY_PRESSURE_EVALUATOR_H_
#define COMPONENTS_MEMORY_PRESSURE_SYSTEM_MEMORY_PRESSURE_EVALUATOR_H_
#include "base/memory/memory_pressure_listener.h"
#include "base/time/time.h"
#include "components/memory_pressure/memory_pressure_voter.h"
#include "components/memory_pressure/multi_source_memory_pressure_monitor.h"
namespace memory_pressure {
// Base class for the platform SystemMemoryPressureEvaluators, which use
// MemoryPressureVoters to cast their vote on the overall MemoryPressureLevel.
class SystemMemoryPressureEvaluator {
public:
// The period at which the system is re-notified when the pressure is not
// none.
static const base::TimeDelta kRenotifyVotePeriod;
// Used by the MemoryPressureMonitor to create the correct Evaluator for the
// platform in use.
static std::unique_ptr<SystemMemoryPressureEvaluator>
CreateDefaultSystemEvaluator(MultiSourceMemoryPressureMonitor* monitor);
virtual ~SystemMemoryPressureEvaluator();
SystemMemoryPressureEvaluator(const SystemMemoryPressureEvaluator&) = delete;
SystemMemoryPressureEvaluator& operator=(
const SystemMemoryPressureEvaluator&) = delete;
base::MemoryPressureListener::MemoryPressureLevel current_vote() const {
return current_vote_;
}
protected:
explicit SystemMemoryPressureEvaluator(
std::unique_ptr<MemoryPressureVoter> voter);
// Sets the Evaluator's |current_vote_| member without casting vote to the
// MemoryPressureVoteAggregator.
void SetCurrentVote(base::MemoryPressureListener::MemoryPressureLevel level);
// Uses the Evaluators' |voter_| to cast/update its vote on memory pressure
// level. The MemoryPressureListeners will only be notified of the newly
// calculated pressure level if |notify| is true.
void SendCurrentVote(bool notify) const;
private:
base::MemoryPressureListener::MemoryPressureLevel current_vote_;
// In charge of forwarding votes from here to the
// MemoryPressureVoteAggregator.
std::unique_ptr<MemoryPressureVoter> voter_;
SEQUENCE_CHECKER(sequence_checker_);
};
} // namespace memory_pressure
#endif // COMPONENTS_MEMORY_PRESSURE_SYSTEM_MEMORY_PRESSURE_EVALUATOR_H_
|
