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// Copyright 2020 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef CHROME_BROWSER_PERFORMANCE_MANAGER_POLICIES_URGENT_PAGE_DISCARDING_POLICY_H_
#define CHROME_BROWSER_PERFORMANCE_MANAGER_POLICIES_URGENT_PAGE_DISCARDING_POLICY_H_
#include <optional>
#include "base/memory/memory_pressure_listener.h"
#include "base/sequence_checker.h"
#include "build/build_config.h"
#include "components/memory_pressure/reclaim_target.h"
#include "components/performance_manager/public/graph/graph.h"
#include "components/performance_manager/public/graph/system_node.h"
namespace performance_manager {
namespace policies {
// Urgently discard a tab when receiving a memory pressure signal.
class UrgentPageDiscardingPolicy : public GraphOwned,
public SystemNodeObserver {
public:
UrgentPageDiscardingPolicy();
~UrgentPageDiscardingPolicy() override;
UrgentPageDiscardingPolicy(const UrgentPageDiscardingPolicy& other) = delete;
UrgentPageDiscardingPolicy& operator=(const UrgentPageDiscardingPolicy&) =
delete;
// GraphOwned implementation:
void OnPassedToGraph(Graph* graph) override;
void OnTakenFromGraph(Graph* graph) override;
// When invoked, the policy will not discard pages on memory pressure.
static void DisableForTesting();
private:
// SystemNodeObserver:
void OnMemoryPressure(
base::MemoryPressureListener::MemoryPressureLevel new_level) override;
// Callback called when a discard attempt has completed.
void PostDiscardAttemptCallback(bool success);
#if BUILDFLAG(IS_CHROMEOS)
// Called when the reclaim target is ready.
void OnReclaimTarget(
base::TimeTicks on_memory_pressure_at,
std::optional<memory_pressure::ReclaimTarget> reclaim_target_kb);
#endif // BUILDFLAG(IS_CHROMEOS)
// True while we are in the process of discarding tab(s) in response to a
// memory pressure notification. It becomes false once we're done responding
// to this notification.
bool handling_memory_pressure_notification_ = false;
SEQUENCE_CHECKER(sequence_checker_);
};
} // namespace policies
} // namespace performance_manager
#endif // CHROME_BROWSER_PERFORMANCE_MANAGER_POLICIES_URGENT_PAGE_DISCARDING_POLICY_H_
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