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// 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 BASE_MEMORY_DISCARDABLE_MEMORY_INTERNAL_H_
#define BASE_MEMORY_DISCARDABLE_MEMORY_INTERNAL_H_
#include <array>
#include "base/base_export.h"
#include "base/feature_list.h"
#include "base/metrics/field_trial_params.h"
#include "build/build_config.h"
#if BUILDFLAG(IS_ANDROID) || BUILDFLAG(IS_LINUX) || BUILDFLAG(IS_CHROMEOS)
namespace base {
// Enumeration of the possible experiment groups in the discardable memory
// backing trial. Note that |kAshmem| and |kEmulatedSharedMemory| both map to
// discardable shared memory, except the former allows for the use of ashmem for
// unpinning memory. Ensure that the order of the enum values matches those in
// |kDiscardableMemoryBackingParamOptions|.
enum DiscardableMemoryTrialGroup : int {
kEmulatedSharedMemory = 0,
kMadvFree,
// Only Android devices will be assigned to the ashmem group.
kAshmem,
};
namespace features {
// Feature flag enabling the discardable memory backing trial.
BASE_EXPORT BASE_DECLARE_FEATURE(kDiscardableMemoryBackingTrial);
// Association of trial group names to trial group enum. Array order must match
// order of DiscardableMemoryTrialGroup enum.
constexpr inline auto kDiscardableMemoryBackingParamOptions =
std::to_array<base::FeatureParam<DiscardableMemoryTrialGroup>::Option>({
{DiscardableMemoryTrialGroup::kEmulatedSharedMemory, "shmem"},
{DiscardableMemoryTrialGroup::kMadvFree, "madvfree"},
{DiscardableMemoryTrialGroup::kAshmem, "ashmem"},
});
BASE_EXPORT BASE_DECLARE_FEATURE_PARAM(DiscardableMemoryTrialGroup,
kDiscardableMemoryBackingParam);
} // namespace features
// Whether we should do the discardable memory backing trial for this session.
BASE_EXPORT bool DiscardableMemoryBackingFieldTrialIsEnabled();
// If we should do the discardable memory backing trial, then get the trial
// group this session belongs in.
BASE_EXPORT DiscardableMemoryTrialGroup
GetDiscardableMemoryBackingFieldTrialGroup();
} // namespace base
#endif // BUILDFLAG(IS_LINUX) || BUILDFLAG(IS_CHROMEOS) ||
// BUILDFLAG(IS_ANDROID)
#endif // BASE_MEMORY_DISCARDABLE_MEMORY_INTERNAL_H_
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