| /* |
| * Copyright (C) 2020 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package com.android.internal.os; |
| |
| import android.annotation.Nullable; |
| import android.os.Process; |
| |
| import com.android.internal.annotations.VisibleForTesting; |
| |
| import java.io.IOException; |
| |
| /** |
| * Reads /proc/UID/task/TID/time_in_state files to obtain statistics on CPU usage |
| * by various threads of the System Server. |
| */ |
| public class SystemServerCpuThreadReader { |
| private final KernelSingleProcessCpuThreadReader mKernelCpuThreadReader; |
| |
| private long[] mLastThreadCpuTimesUs; |
| private long[] mLastBinderThreadCpuTimesUs; |
| |
| /** |
| * Times (in microseconds) spent by the system server UID. |
| */ |
| public static class SystemServiceCpuThreadTimes { |
| // All threads |
| public long[] threadCpuTimesUs; |
| // Just the threads handling incoming binder calls |
| public long[] binderThreadCpuTimesUs; |
| } |
| |
| private final SystemServiceCpuThreadTimes mDeltaCpuThreadTimes = |
| new SystemServiceCpuThreadTimes(); |
| |
| /** |
| * Creates a configured instance of SystemServerCpuThreadReader. |
| */ |
| public static SystemServerCpuThreadReader create() { |
| return new SystemServerCpuThreadReader( |
| KernelSingleProcessCpuThreadReader.create(Process.myPid())); |
| } |
| |
| @VisibleForTesting |
| public SystemServerCpuThreadReader(int pid, |
| KernelSingleProcessCpuThreadReader.CpuTimeInStateReader cpuTimeInStateReader) |
| throws IOException { |
| this(new KernelSingleProcessCpuThreadReader(pid, cpuTimeInStateReader)); |
| } |
| |
| @VisibleForTesting |
| public SystemServerCpuThreadReader(KernelSingleProcessCpuThreadReader kernelCpuThreadReader) { |
| mKernelCpuThreadReader = kernelCpuThreadReader; |
| } |
| |
| /** |
| * Start tracking CPU time-in-state for the process specified in the constructor. |
| */ |
| public void startTrackingThreadCpuTime() { |
| mKernelCpuThreadReader.startTrackingThreadCpuTimes(); |
| } |
| |
| public void setBinderThreadNativeTids(int[] nativeTids) { |
| mKernelCpuThreadReader.setSelectedThreadIds(nativeTids); |
| } |
| |
| /** |
| * Returns delta of CPU times, per thread, since the previous call to this method. |
| */ |
| @Nullable |
| public SystemServiceCpuThreadTimes readDelta() { |
| final int numCpuFrequencies = mKernelCpuThreadReader.getCpuFrequencyCount(); |
| if (mLastThreadCpuTimesUs == null) { |
| mLastThreadCpuTimesUs = new long[numCpuFrequencies]; |
| mLastBinderThreadCpuTimesUs = new long[numCpuFrequencies]; |
| |
| mDeltaCpuThreadTimes.threadCpuTimesUs = new long[numCpuFrequencies]; |
| mDeltaCpuThreadTimes.binderThreadCpuTimesUs = new long[numCpuFrequencies]; |
| } |
| |
| final KernelSingleProcessCpuThreadReader.ProcessCpuUsage processCpuUsage = |
| mKernelCpuThreadReader.getProcessCpuUsage(); |
| if (processCpuUsage == null) { |
| return null; |
| } |
| |
| for (int i = numCpuFrequencies - 1; i >= 0; i--) { |
| long threadCpuTimesUs = processCpuUsage.threadCpuTimesMillis[i] * 1000; |
| long binderThreadCpuTimesUs = processCpuUsage.selectedThreadCpuTimesMillis[i] * 1000; |
| mDeltaCpuThreadTimes.threadCpuTimesUs[i] = |
| Math.max(0, threadCpuTimesUs - mLastThreadCpuTimesUs[i]); |
| mDeltaCpuThreadTimes.binderThreadCpuTimesUs[i] = |
| Math.max(0, binderThreadCpuTimesUs - mLastBinderThreadCpuTimesUs[i]); |
| mLastThreadCpuTimesUs[i] = threadCpuTimesUs; |
| mLastBinderThreadCpuTimesUs[i] = binderThreadCpuTimesUs; |
| } |
| |
| return mDeltaCpuThreadTimes; |
| } |
| |
| /** Returns CPU times, per thread group, since tracking started. */ |
| @Nullable |
| public SystemServiceCpuThreadTimes readAbsolute() { |
| final int numCpuFrequencies = mKernelCpuThreadReader.getCpuFrequencyCount(); |
| final KernelSingleProcessCpuThreadReader.ProcessCpuUsage processCpuUsage = |
| mKernelCpuThreadReader.getProcessCpuUsage(); |
| if (processCpuUsage == null) { |
| return null; |
| } |
| final SystemServiceCpuThreadTimes result = new SystemServiceCpuThreadTimes(); |
| result.threadCpuTimesUs = new long[numCpuFrequencies]; |
| result.binderThreadCpuTimesUs = new long[numCpuFrequencies]; |
| for (int i = 0; i < numCpuFrequencies; ++i) { |
| result.threadCpuTimesUs[i] = processCpuUsage.threadCpuTimesMillis[i] * 1_000; |
| result.binderThreadCpuTimesUs[i] = |
| processCpuUsage.selectedThreadCpuTimesMillis[i] * 1_000; |
| } |
| return result; |
| } |
| } |