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// Copyright 2013 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "base/android/sys_utils.h"
#include <memory>
#include "base/android/build_info.h"
#include "base/feature_list.h"
#include "base/process/process_metrics.h"
#include "base/system/sys_info.h"
#include "base/trace_event/base_tracing.h"
// Must come after all headers that specialize FromJniType() / ToJniType().
#include "base/sys_utils_jni/SysUtils_jni.h"
namespace base {
namespace android {
enum class IsLowMemoryOptions {
kAlwaysFalse,
kAlwaysTrue,
kJavalessApproximation
};
const base::FeatureParam<IsLowMemoryOptions>::Option kIsLowMemoryOptions[] = {
{IsLowMemoryOptions::kAlwaysFalse, "AlwaysFalse"},
{IsLowMemoryOptions::kAlwaysTrue, "AlwaysTrue"},
{IsLowMemoryOptions::kJavalessApproximation, "JavalessApproximation"}};
BASE_FEATURE(kIsCurrentlyLowMemoryJavaless,
"IsCurrentlyLowMemoryJavaless",
base::FEATURE_DISABLED_BY_DEFAULT);
BASE_FEATURE_ENUM_PARAM(IsLowMemoryOptions,
kIsCurrentlyLowMemoryOption,
&kIsCurrentlyLowMemoryJavaless,
"IsCurrentlyLowMemoryOption",
IsLowMemoryOptions::kJavalessApproximation,
&kIsLowMemoryOptions);
bool SysUtils::IsCurrentlyLowMemory() {
if (!FeatureList::IsEnabled(kIsCurrentlyLowMemoryJavaless)) {
return Java_SysUtils_isCurrentlyLowMemory(AttachCurrentThread());
}
switch (kIsCurrentlyLowMemoryOption.Get()) {
case IsLowMemoryOptions::kAlwaysFalse:
return false;
case IsLowMemoryOptions::kAlwaysTrue:
return true;
case IsLowMemoryOptions::kJavalessApproximation:
// Picked 138240 as it is the number we used to check against in Java's
// MemoryInfo.lowMemory. There are a lot of exceptions and edge cases,
// but capturing all them likely isn't worth it, so using the basic number
// instead. To see where this number is calculated, look at
// https://android.googlesource.com/platform/frameworks/base/+/a8e26bab3b8b3d939da5c646411578b565735473/services/core/java/com/android/server/am/ProcessList.java#1743
return base::SysInfo::AmountOfAvailablePhysicalMemory() < 138240;
}
}
// Logs the number of minor / major page faults to tracing (and also the time to
// collect) the metrics. Does nothing if tracing is not enabled.
static void JNI_SysUtils_LogPageFaultCountToTracing(JNIEnv* env) {
// This is racy, but we are OK losing data, and collecting it is potentially
// expensive (reading and parsing a file).
bool enabled;
TRACE_EVENT_CATEGORY_GROUP_ENABLED("startup", &enabled);
if (!enabled) {
return;
}
TRACE_EVENT_BEGIN2("memory", "CollectPageFaultCount", "minor", 0, "major", 0);
std::unique_ptr<base::ProcessMetrics> process_metrics(
base::ProcessMetrics::CreateProcessMetrics(
base::GetCurrentProcessHandle()));
base::PageFaultCounts counts;
process_metrics->GetPageFaultCounts(&counts);
TRACE_EVENT_END2("memory", "CollectPageFaults", "minor", counts.minor,
"major", counts.major);
}
} // namespace android
} // namespace base
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