1 /*
2  * Copyright (C) 2020 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 package com.android.internal.os;
18 
19 import android.annotation.Nullable;
20 
21 /** Reads total CPU time bpf map. */
22 public final class KernelCpuTotalBpfMapReader {
KernelCpuTotalBpfMapReader()23     private KernelCpuTotalBpfMapReader() {
24     }
25 
26     /** Reads total CPU times (excluding sleep) per frequency in milliseconds from bpf map. */
27     @Nullable
read()28     public static long[] read() {
29         if (!KernelCpuBpfTracking.startTracking()) {
30             return null;
31         }
32         return readInternal();
33     }
34 
35     @Nullable
readInternal()36     private static native long[] readInternal();
37 }
38