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// Copyright 2015 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 COMPONENTS_MEMORY_PRESSURE_DIRECT_MEMORY_PRESSURE_CALCULATOR_WIN_H_
#define COMPONENTS_MEMORY_PRESSURE_DIRECT_MEMORY_PRESSURE_CALCULATOR_WIN_H_
#include "base/macros.h"
#include "base/process/process_metrics.h"
#include "build/build_config.h"
#include "components/memory_pressure/memory_pressure_calculator.h"
namespace memory_pressure {
#if defined(MEMORY_PRESSURE_IS_POLLING)
// OS-specific implementation of MemoryPressureCalculator. This is only defined
// and used on platforms that do not have native memory pressure signals
// (ChromeOS, Linux, Windows). OSes that do have native signals simply hook into
// the appropriate subsystem (Android, Mac OS X).
class DirectMemoryPressureCalculator : public MemoryPressureCalculator {
public:
// Exposed for unittesting. See .cc file for detailed discussion of these
// constants.
static const int kLargeMemoryThresholdMb;
static const int kSmallMemoryDefaultModerateThresholdMb;
static const int kSmallMemoryDefaultCriticalThresholdMb;
static const int kLargeMemoryDefaultModerateThresholdMb;
static const int kLargeMemoryDefaultCriticalThresholdMb;
// Default constructor. Will choose thresholds automatically based on the
// actual amount of system memory installed.
DirectMemoryPressureCalculator();
// Constructor with explicit memory thresholds. These represent the amount of
// free memory below which the applicable memory pressure state applies.
DirectMemoryPressureCalculator(int moderate_threshold_mb,
int critical_threshold_mb);
~DirectMemoryPressureCalculator() override {}
// Calculates the current pressure level.
MemoryPressureLevel CalculateCurrentPressureLevel() override;
int moderate_threshold_mb() const { return moderate_threshold_mb_; }
int critical_threshold_mb() const { return critical_threshold_mb_; }
private:
friend class TestDirectMemoryPressureCalculator;
// Gets system memory status. This is virtual as a unittesting hook and by
// default this invokes base::GetSystemMemoryInfo.
virtual bool GetSystemMemoryInfo(base::SystemMemoryInfoKB* mem_info) const;
// Uses GetSystemMemoryInfo to automatically infer appropriate values for
// moderate_threshold_mb_ and critical_threshold_mb_.
void InferThresholds();
// Threshold amounts of available memory that trigger pressure levels. See
// memory_pressure_monitor_win.cc for a discussion of reasonable values for
// these.
int moderate_threshold_mb_;
int critical_threshold_mb_;
DISALLOW_COPY_AND_ASSIGN(DirectMemoryPressureCalculator);
};
#endif // defined(MEMORY_PRESSURE_IS_POLLING)
} // namespace memory_pressure
#endif // COMPONENTS_MEMORY_PRESSURE_DIRECT_MEMORY_PRESSURE_CALCULATOR_WIN_H_
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