Obtenir l'utilisation de la mémoire dans Android
Existe-t-il une API par laquelle nous pouvons obtenir l'utilisation du processeur ou de la mémoire d'Android?
J'ai essayé un code comme ci-dessous:
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();
}
}
}
Est-ce la bonne façon de procéder?
J'utilise cette fonction pour calculer l'utilisation du processeur. J'espère que ça peut t'aider.
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;
}
Un moyen simple de vérifier l'utilisation du processeur est d'utiliser l'outil adb w/top. C'est à dire.:
adb Shell top -m 10
Sur la base des réponses précédentes et de l'expérience personnelle, voici le code que j'utilise pour surveiller l'utilisation du CPU. Le code de cette classe est écrit en Java pur.
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>
* @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(mOutput, "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(mOutput, "" + pid, Float.toString(cpu));
* }
*
* try {
* synchronized (this) {
* wait(CPU_REFRESH_RATE);
* }
* } catch (InterruptedException e) {
* e.printStackTrace();
* return;
* }
* }
*
* Log.i("THREAD CPU", "Finishing");
* }
* </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);
}
}
Il existe plusieurs façons d'exploiter cette classe. Vous pouvez appeler syncGetSystemCpuUsage ou syncGetProcessCpuUsage mais chacun bloque le thread appelant. Puisqu'un problème courant est de surveiller l'utilisation totale du processeur et l'utilisation du processeur du processus actuel en même temps, j'ai conçu une classe de calcul pour les deux. Cette classe contient un thread dédié. La gestion des sorties est spécifique à l'implémentation et vous devez coder la vôtre.
La classe peut être personnalisée par plusieurs moyens. La constante CPU_WINDOW définit la profondeur d'une lecture, c'est-à-dire le nombre de millisecondes entre les lectures et le calcul de la charge CPU correspondante. CPU_REFRESH_RATE est le temps entre chaque mesure de charge CPU. Ne pas fixer CPU_REFRESH_RATE à 0 car il suspendra le thread après la première lecture.
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);
}
}
Étant donné que l'OP a posé des questions sur l'utilisation du processeur ET l'utilisation de la mémoire (la réponse acceptée ne montre que la technique pour obtenir l'utilisation du processeur), je voudrais recommander la classe ActivityManager et en particulier la réponse acceptée de cette question: Comment obtenir l'utilisation actuelle de la mémoire dans android?
Vérifiez la classe Debug. http://developer.Android.com/reference/Android/os/Debug.html c'est-à-dire Debug.getNativeHeapAllocatedSize()
Il a des méthodes pour obtenir le tas natif utilisé, c'est-à-dire utilisé par des bitmaps externes dans votre application. Pour le tas que l'application utilise en interne, vous pouvez le voir dans l'outil DDMS fourni avec le SDK Android Android et également disponible via Eclipse.
Le tas natif + le tas comme indiqué dans le DDMS constituent le tas total que votre application alloue.
Pour l'utilisation du processeur, je ne sais pas s'il y a quelque chose de disponible via API/SDK.