58 lines
2.0 KiB
Java
58 lines
2.0 KiB
Java
/*
|
|
* Copyright (C) 2021 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;
|
|
|
|
/**
|
|
* Reads CPU usage statistics about a selected process identified by its cmdline.
|
|
*
|
|
* Handles finding the pid for the process and delegates CPU usage reading from the eBPF map to
|
|
* KernelSingleProcessCpuThreadReader. Exactly one long-lived instance of the process is expected.
|
|
* Otherwise, no statistics are returned.
|
|
*
|
|
* See also SystemServerCpuThreadReader.
|
|
*/
|
|
public final class SelectedProcessCpuThreadReader {
|
|
private final String[] mCmdline;
|
|
|
|
private int mPid;
|
|
private KernelSingleProcessCpuThreadReader mKernelCpuThreadReader;
|
|
|
|
public SelectedProcessCpuThreadReader(String cmdline) {
|
|
mCmdline = new String[] { cmdline };
|
|
}
|
|
|
|
/** Returns CPU times, per thread group, since tracking started. */
|
|
@Nullable
|
|
public KernelSingleProcessCpuThreadReader.ProcessCpuUsage readAbsolute() {
|
|
int[] pids = Process.getPidsForCommands(mCmdline);
|
|
if (pids == null || pids.length != 1) {
|
|
return null;
|
|
}
|
|
int pid = pids[0];
|
|
if (mPid == pid) {
|
|
return mKernelCpuThreadReader.getProcessCpuUsage();
|
|
}
|
|
mPid = pid;
|
|
mKernelCpuThreadReader = KernelSingleProcessCpuThreadReader.create(mPid);
|
|
mKernelCpuThreadReader.startTrackingThreadCpuTimes();
|
|
return null;
|
|
}
|
|
}
|