Get Memory Usage in Android

Question

Is there any API by which we can get CPU or Memory usage of android?

I have tried one code as below:

package com.infostretch.mainactivity;

import java.io.BufferedReader;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStreamReader;

public class CPULoad 
{
    long total = 0;
    long idle = 0;

    float usage = 0;

    public CPULoad()
    {
        readUsage();
    }

    public float getUsage()
    {
        readUsage();
        return usage;
    }

    private void readUsage()
    {
        try
        {
            BufferedReader reader = new BufferedReader(new InputStreamReader(new FileInputStream("/proc/stat")), 1000);
            String load = reader.readLine();
            reader.close();

            String[] toks = load.split(" ");

            long currTotal = Long.parseLong(toks[2]) + Long.parseLong(toks[3]) + Long.parseLong(toks[4]);
            long currIdle = Long.parseLong(toks[5]);

            this.usage = (currTotal - total) * 100.0f / (currTotal - total + currIdle - idle);
            this.total = currTotal;
            this.idle = currIdle;
        }
        catch(IOException ex)
        {
            ex.printStackTrace();
        }
    }
}

Is this the correct way to do it?

Answer 1

enter the android terminal and then you can type the following commands :dumpsys cpuinfo

shell@android:/ $ dumpsys cpuinfo                                              
Load: 0.8 / 0.75 / 1.15
CPU usage from 69286ms to 9283ms ago with 99% awake:
  47% 1118/com.wxg.sodproject: 12% user + 35% kernel
  1.6% 1225/android.process.media: 1% user + 0.6% kernel
  1.3% 263/mpdecision: 0.1% user + 1.2% kernel
  0.1% 32747/kworker/u:1: 0% user + 0.1% kernel
  0.1% 883/com.android.systemui: 0.1% user + 0% kernel
  0.1% 521/system_server: 0.1% user + 0% kernel / faults: 14 minor
  0.1% 1826/com.quicinc.trepn: 0.1% user + 0% kernel
  0.1% 2462/kworker/0:2: 0.1% user + 0% kernel
  0.1% 32649/kworker/0:0: 0% user + 0.1% kernel
  0% 118/mmcqd/0: 0% user + 0% kernel
  0% 179/surfaceflinger: 0% user + 0% kernel
  0% 46/kinteractiveup: 0% user + 0% kernel
  0% 141/jbd2/mmcblk0p26: 0% user + 0% kernel
  0% 239/sdcard: 0% user + 0% kernel
  0% 1171/com.xiaomi.channel:pushservice: 0% user + 0% kernel / faults: 1 minor
  0% 1207/com.xiaomi.channel: 0% user + 0% kernel / faults: 1 minor
  0% 32705/kworker/0:1: 0% user + 0% kernel
12% TOTAL: 3.2% user + 9.4% kernel + 0% iowait

Answer 2

Based on the previous answers and personnal experience, here is the code I use to monitor CPU use. The code of this class is written in pure Java.

import java.io.IOException;
import java.io.RandomAccessFile;

/**
 * Utilities available only on Linux Operating System.
 * 
 * <p>
 * A typical use is to assign a thread to CPU monitoring:
 * </p>
 * 
 * <pre>
 * &#064;Override
 * public void run() {
 *  while (CpuUtil.monitorCpu) {
 * 
 *      LinuxUtils linuxUtils = new LinuxUtils();
 * 
 *      int pid = android.os.Process.myPid();
 *      String cpuStat1 = linuxUtils.readSystemStat();
 *      String pidStat1 = linuxUtils.readProcessStat(pid);
 * 
 *      try {
 *          Thread.sleep(CPU_WINDOW);
 *      } catch (Exception e) {
 *      }
 * 
 *      String cpuStat2 = linuxUtils.readSystemStat();
 *      String pidStat2 = linuxUtils.readProcessStat(pid);
 * 
 *      float cpu = linuxUtils.getSystemCpuUsage(cpuStat1, cpuStat2);
 *      if (cpu &gt;= 0.0f) {
 *          _printLine(mOutput, &quot;total&quot;, Float.toString(cpu));
 *      }
 * 
 *      String[] toks = cpuStat1.split(&quot; &quot;);
 *      long cpu1 = linuxUtils.getSystemUptime(toks);
 * 
 *      toks = cpuStat2.split(&quot; &quot;);
 *      long cpu2 = linuxUtils.getSystemUptime(toks);
 * 
 *      cpu = linuxUtils.getProcessCpuUsage(pidStat1, pidStat2, cpu2 - cpu1);
 *      if (cpu &gt;= 0.0f) {
 *          _printLine(mOutput, &quot;&quot; + pid, Float.toString(cpu));
 *      }
 * 
 *      try {
 *          synchronized (this) {
 *              wait(CPU_REFRESH_RATE);
 *          }
 *      } catch (InterruptedException e) {
 *          e.printStackTrace();
 *          return;
 *      }
 *  }
 * 
 *  Log.i(&quot;THREAD CPU&quot;, &quot;Finishing&quot;);
 * }
 * </pre>
 */
public final class LinuxUtils {

    // Warning: there appears to be an issue with the column index with android linux:
    // it was observed that on most present devices there are actually
    // two spaces between the 'cpu' of the first column and the value of 
    // the next column with data. The thing is the index of the idle 
    // column should have been 4 and the first column with data should have index 1. 
    // The indexes defined below are coping with the double space situation.
    // If your file contains only one space then use index 1 and 4 instead of 2 and 5.
    // A better way to deal with this problem may be to use a split method 
    // not preserving blanks or compute an offset and add it to the indexes 1 and 4.

    private static final int FIRST_SYS_CPU_COLUMN_INDEX = 2;

    private static final int IDLE_SYS_CPU_COLUMN_INDEX = 5;

    /** Return the first line of /proc/stat or null if failed. */
    public String readSystemStat() {

        RandomAccessFile reader = null;
        String load = null;

        try {
            reader = new RandomAccessFile("/proc/stat", "r");
            load = reader.readLine();
        } catch (IOException ex) {
            ex.printStackTrace();
        } finally {
            Streams.close(reader);
        }

        return load;
    }

    /**
     * Compute and return the total CPU usage, in percent.
     * 
     * @param start
     *            first content of /proc/stat. Not null.
     * @param end
     *            second content of /proc/stat. Not null.
     * @return 12.7 for a CPU usage of 12.7% or -1 if the value is not
     *         available.
     * @see {@link #readSystemStat()}
     */
    public float getSystemCpuUsage(String start, String end) {
        String[] stat = start.split("\\s");
        long idle1 = getSystemIdleTime(stat);
        long up1 = getSystemUptime(stat);

        stat = end.split("\\s");
        long idle2 = getSystemIdleTime(stat);
        long up2 = getSystemUptime(stat);

        // don't know how it is possible but we should care about zero and
        // negative values.
        float cpu = -1f;
        if (idle1 >= 0 && up1 >= 0 && idle2 >= 0 && up2 >= 0) {
            if ((up2 + idle2) > (up1 + idle1) && up2 >= up1) {
                cpu = (up2 - up1) / (float) ((up2 + idle2) - (up1 + idle1));
                cpu *= 100.0f;
            }
        }

        return cpu;
    }

    /**
     * Return the sum of uptimes read from /proc/stat.
     * 
     * @param stat
     *            see {@link #readSystemStat()}
     */
    public long getSystemUptime(String[] stat) {
        /*
         * (from man/5/proc) /proc/stat kernel/system statistics. Varies with
         * architecture. Common entries include: cpu 3357 0 4313 1362393
         * 
         * The amount of time, measured in units of USER_HZ (1/100ths of a
         * second on most architectures, use sysconf(_SC_CLK_TCK) to obtain the
         * right value), that the system spent in user mode, user mode with low
         * priority (nice), system mode, and the idle task, respectively. The
         * last value should be USER_HZ times the second entry in the uptime
         * pseudo-file.
         * 
         * In Linux 2.6 this line includes three additional columns: iowait -
         * time waiting for I/O to complete (since 2.5.41); irq - time servicing
         * interrupts (since 2.6.0-test4); softirq - time servicing softirqs
         * (since 2.6.0-test4).
         * 
         * Since Linux 2.6.11, there is an eighth column, steal - stolen time,
         * which is the time spent in other operating systems when running in a
         * virtualized environment
         * 
         * Since Linux 2.6.24, there is a ninth column, guest, which is the time
         * spent running a virtual CPU for guest operating systems under the
         * control of the Linux kernel.
         */

        // with the following algorithm, we should cope with all versions and
        // probably new ones.
        long l = 0L;

        for (int i = FIRST_SYS_CPU_COLUMN_INDEX; i < stat.length; i++) {
            if (i != IDLE_SYS_CPU_COLUMN_INDEX ) { // bypass any idle mode. There is currently only one.
                try {
                    l += Long.parseLong(stat[i]);
                } catch (NumberFormatException ex) {
                    ex.printStackTrace();
                    return -1L;
                }
            }
        }

        return l;
    }

    /**
     * Return the sum of idle times read from /proc/stat.
     * 
     * @param stat
     *            see {@link #readSystemStat()}
     */
    public long getSystemIdleTime(String[] stat) {
        try {
            return Long.parseLong(stat[IDLE_SYS_CPU_COLUMN_INDEX]);
        } catch (NumberFormatException ex) {
            ex.printStackTrace();
        }

        return -1L;
    }

    /** Return the first line of /proc/pid/stat or null if failed. */
    public String readProcessStat(int pid) {

        RandomAccessFile reader = null;
        String line = null;

        try {
            reader = new RandomAccessFile("/proc/" + pid + "/stat", "r");
            line = reader.readLine();
        } catch (IOException ex) {
            ex.printStackTrace();
        } finally {
            Streams.close(reader);
        }

        return line;
    }

    /**
     * Compute and return the CPU usage for a process, in percent.
     * 
     * <p>
     * The parameters {@code totalCpuTime} is to be the one for the same period
     * of time delimited by {@code statStart} and {@code statEnd}.
     * </p>
     * 
     * @param start
     *            first content of /proc/pid/stat. Not null.
     * @param end
     *            second content of /proc/pid/stat. Not null.
     * @return the CPU use in percent or -1f if the stats are inverted or on
     *         error
     * @param uptime
     *            sum of user and kernel times for the entire system for the
     *            same period of time.
     * @return 12.7 for a cpu usage of 12.7% or -1 if the value is not available
     *         or an error occurred.
     * @see {@link #readProcessStat(int)}
     */
    public float getProcessCpuUsage(String start, String end, long uptime) {

        String[] stat = start.split("\\s");
        long up1 = getProcessUptime(stat);

        stat = end.split("\\s");
        long up2 = getProcessUptime(stat);

        float ret = -1f;
        if (up1 >= 0 && up2 >= up1 && uptime > 0.) {
            ret = 100.f * (up2 - up1) / (float) uptime;
        }

        return ret;
    }

    /**
     * Decode the fields of the file {@code /proc/pid/stat} and return (utime +
     * stime)
     * 
     * @param stat
     *            obtained with {@link #readProcessStat(int)}
     */
    public long getProcessUptime(String[] stat) {
        return Long.parseLong(stat[14]) + Long.parseLong(stat[15]);
    }

    /**
     * Decode the fields of the file {@code /proc/pid/stat} and return (cutime +
     * cstime)
     * 
     * @param stat
     *            obtained with {@link #readProcessStat(int)}
     */
    public long getProcessIdleTime(String[] stat) {
        return Long.parseLong(stat[16]) + Long.parseLong(stat[17]);
    }

    /**
     * Return the total CPU usage, in percent.
     * <p>
     * The call is blocking for the time specified by elapse.
     * </p>
     * 
     * @param elapse
     *            the time in milliseconds between reads.
     * @return 12.7 for a CPU usage of 12.7% or -1 if the value is not
     *         available.
     */
    public float syncGetSystemCpuUsage(long elapse) {

        String stat1 = readSystemStat();
        if (stat1 == null) {
            return -1.f;
        }

        try {
            Thread.sleep(elapse);
        } catch (Exception e) {
        }

        String stat2 = readSystemStat();
        if (stat2 == null) {
            return -1.f;
        }

        return getSystemCpuUsage(stat1, stat2);
    }

    /**
     * Return the CPU usage of a process, in percent.
     * <p>
     * The call is blocking for the time specified by elapse.
     * </p>
     * 
     * @param pid
     * @param elapse
     *            the time in milliseconds between reads.
     * @return 6.32 for a CPU usage of 6.32% or -1 if the value is not
     *         available.
     */
    public float syncGetProcessCpuUsage(int pid, long elapse) {

        String pidStat1 = readProcessStat(pid);
        String totalStat1 = readSystemStat();
        if (pidStat1 == null || totalStat1 == null) {
            return -1.f;
        }

        try {
            Thread.sleep(elapse);
        } catch (Exception e) {
            e.printStackTrace();
            return -1.f;
        }

        String pidStat2 = readProcessStat(pid);
        String totalStat2 = readSystemStat();
        if (pidStat2 == null || totalStat2 == null) {
            return -1.f;
        }

        String[] toks = totalStat1.split("\\s");
        long cpu1 = getSystemUptime(toks);

        toks = totalStat2.split("\\s");
        long cpu2 = getSystemUptime(toks);

        return getProcessCpuUsage(pidStat1, pidStat2, cpu2 - cpu1);
    }

}

There are several ways of exploiting this class. You can call either syncGetSystemCpuUsage or syncGetProcessCpuUsage but each is blocking the calling thread. Since a common issue is to monitor the total CPU usage and the CPU use of the current process at the same time, I have designed a class computing both of them. That class contains a dedicated thread. The output management is implementation specific and you need to code your own.

The class can be customized by a few means. The constant CPU_WINDOW defines the depth of a read, i.e. the number of milliseconds between readings and computing of the corresponding CPU load. CPU_REFRESH_RATE is the time between each CPU load measurement. Do not set CPU_REFRESH_RATE to 0 because it will suspend the thread after the first read.

import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.OutputStream;

import android.app.Application;
import android.os.Handler;
import android.os.HandlerThread;
import android.util.Log;

import my.app.LinuxUtils;
import my.app.Streams;
import my.app.TestReport;
import my.app.Utils;

public final class CpuUtil {

    private static final int CPU_WINDOW = 1000;

    private static final int CPU_REFRESH_RATE = 100; // Warning: anything but > 0

    private static HandlerThread handlerThread;

    private static TestReport output;

    static {
        output = new TestReport();
        output.setDateFormat(Utils.getDateFormat(Utils.DATE_FORMAT_ENGLISH));
    }

    private static boolean monitorCpu;

    /**
     * Construct the class singleton. This method should be called in
     * {@link Application#onCreate()}
     * 
     * @param dir
     *            the parent directory
     * @param append
     *            mode
     */
    public static void setOutput(File dir, boolean append) {
        try {
            File file = new File(dir, "cpu.txt");
            output.setOutputStream(new FileOutputStream(file, append));
            if (!append) {
                output.println(file.getAbsolutePath());
                output.newLine(1);

                // print header
                _printLine(output, "Process", "CPU%");

                output.flush();
            }

        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }
    }

    /** Start CPU monitoring */
    public static boolean startCpuMonitoring() {
        CpuUtil.monitorCpu = true;

        handlerThread = new HandlerThread("CPU monitoring"); //$NON-NLS-1$
        handlerThread.start();

        Handler handler = new Handler(handlerThread.getLooper());
        handler.post(new Runnable() {

            @Override
            public void run() {
                while (CpuUtil.monitorCpu) {

                    LinuxUtils linuxUtils = new LinuxUtils();

                    int pid = android.os.Process.myPid();
                    String cpuStat1 = linuxUtils.readSystemStat();
                    String pidStat1 = linuxUtils.readProcessStat(pid);

                    try {
                        Thread.sleep(CPU_WINDOW);
                    } catch (Exception e) {
                    }

                    String cpuStat2 = linuxUtils.readSystemStat();
                    String pidStat2 = linuxUtils.readProcessStat(pid);

                    float cpu = linuxUtils
                            .getSystemCpuUsage(cpuStat1, cpuStat2);
                    if (cpu >= 0.0f) {
                        _printLine(output, "total", Float.toString(cpu));
                    }

                    String[] toks = cpuStat1.split(" ");
                    long cpu1 = linuxUtils.getSystemUptime(toks);

                    toks = cpuStat2.split(" ");
                    long cpu2 = linuxUtils.getSystemUptime(toks);

                    cpu = linuxUtils.getProcessCpuUsage(pidStat1, pidStat2,
                            cpu2 - cpu1);
                    if (cpu >= 0.0f) {
                        _printLine(output, "" + pid, Float.toString(cpu));
                    }

                    try {
                        synchronized (this) {
                            wait(CPU_REFRESH_RATE);
                        }
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                        return;
                    }
                }

                Log.i("THREAD CPU", "Finishing");
            }

        });

        return CpuUtil.monitorCpu;
    }

    /** Stop CPU monitoring */
    public static void stopCpuMonitoring() {
        if (handlerThread != null) {
            monitorCpu = false;
            handlerThread.quit();
            handlerThread = null;
        }
    }

    /** Dispose of the object and release the resources allocated for it */
    public void dispose() {

        monitorCpu = false;

        if (output != null) {
            OutputStream os = output.getOutputStream();
            if (os != null) {
                Streams.close(os);
                output.setOutputStream(null);
            }

            output = null;
        }
    }

    private static void _printLine(TestReport output, String process, String cpu) {
        output.stampln(process + ";" + cpu);
    }

}

Answer 3

I use this function to calculate cpu usage. Hope it can help you.

private float readUsage() {
    try {
        RandomAccessFile reader = new RandomAccessFile("/proc/stat", "r");
        String load = reader.readLine();

        String[] toks = load.split(" +");  // Split on one or more spaces

        long idle1 = Long.parseLong(toks[4]);
        long cpu1 = Long.parseLong(toks[2]) + Long.parseLong(toks[3]) + Long.parseLong(toks[5])
              + Long.parseLong(toks[6]) + Long.parseLong(toks[7]) + Long.parseLong(toks[8]);

        try {
            Thread.sleep(360);
        } catch (Exception e) {}

        reader.seek(0);
        load = reader.readLine();
        reader.close();

        toks = load.split(" +");

        long idle2 = Long.parseLong(toks[4]);
        long cpu2 = Long.parseLong(toks[2]) + Long.parseLong(toks[3]) + Long.parseLong(toks[5])
            + Long.parseLong(toks[6]) + Long.parseLong(toks[7]) + Long.parseLong(toks[8]);

        return (float)(cpu2 - cpu1) / ((cpu2 + idle2) - (cpu1 + idle1));

    } catch (IOException ex) {
        ex.printStackTrace();
    }

    return 0;
} 

Answer 4

An easy way to check the CPU usage is to use the adb tool w/ top. I.e.:

adb shell top -m 10

Answer 5

Since the OP asked about CPU usage AND memory usage (accepted answer only shows technique to get cpu usage), I'd like to recommend the ActivityManager class and specifically the accepted answer from this question: How to get current memory usage in android?

Answer 6

Check the Debug class. http://developer.android.com/reference/android/os/Debug.html i.e. Debug.getNativeHeapAllocatedSize()

It has methods to get the used native heap, which is i.e. used by external bitmaps in your app. For the heap that the app is using internally, you can see that in the DDMS tool that comes with the Android SDK and is also available via Eclipse.

The native heap + the heap as indicated in the DDMS make up the total heap that your app is allocating.

For CPU usage I'm not sure if there's anything available via API/SDK.