Android Open Source - EnergyWastingApp C P U Burn

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License

The source code is released under:

Copyright ? 2013-2014 Pekka Ekman <pekka.ekman@aalto.fi> 2013 Babujee Jerome Robin <robin.babujeejerome@aalto.fi> Permission is hereby granted, free of charge, to any person obtaining a ...

Java Source Code

package fi.aalto.pekman.energywastingapp.components;
//  w  w w  . ja  v a 2  s  . com
import android.os.Process;
import android.util.Log;
import android.widget.Toast;

public class CPUBurn extends Component {

  @Override
  public String getName() { return "CPUburn"; }
  
  private static final boolean supported;
  private static final int SIGSTOP;
  private static final int SIGCONT;
  
  @Override
  public boolean isSupported() { return supported; }
  
  
  private static final int PERIOD = 500; // milliseconds
  
  private volatile int onTime = PERIOD;
  private LimiterThread thread = null;
  
  private int[] processes;
  
  private class LimiterThread extends Thread {
    
    public volatile boolean stop = false;
    
    @Override
    public synchronized void run() {
      while (! stop) {
        if (onTime == PERIOD) {
          // onTime == 100% => don't send signals, wait for change
          try {
            wait();
          } catch (InterruptedException e) {}
        }
        else {
          // onTime < 100%
          
          // stop processes for (PERIOD - onTime) milliseconds
          for (int pid : processes)
            Process.sendSignal(pid, SIGSTOP);
          
          try {
            wait(PERIOD - onTime);
          } catch (InterruptedException e) {}
          if (stop)
            break;
          
          // start processes for onTime milliseconds
          for (int pid : processes)
            Process.sendSignal(pid, SIGCONT);
          
          try {
            wait(onTime);
          } catch (InterruptedException e) {}
        }
      }
    }
  }
  
  @Override
  public void start() {
    if (processes != null)
      return;
    
    int numCores = getNumCores();
    if (numCores == -1) {
      Log.w("CPUBurn", "Unable to determine number of cores. Using 1 as fallback value.");
      numCores = 1;
    }
    else {
      Log.d("CPUBurn", numCores + " cores");
    }
    
    // start a process for each CPU core and store the PIDs
    processes = new int[numCores];
    for (int i=0; i<numCores; i++) {
      int pid = 0;
      try {
        pid = startCPUBurn();
        
        if (pid > 0) {
          Log.d("CPUBurn", "forked process (PID=" + pid + ")");
        }
        else {
          Log.e("CPUBurn", "error starting process");
        }
      } catch (UnsatisfiedLinkError e) {
        Log.e("CPUBurn", "error calling native method startCPUBurn()", e);
        pid = 0;
      }
      if (pid <= 0) {
        Toast.makeText(context, "error starting cpuburn process", Toast.LENGTH_LONG)
          .show();
      }
      
      processes[i] = pid;
    }
    
    // start limiter thread
    thread = new LimiterThread();
    thread.start();
  }
  
  @Override
  public void stop() {
    if (processes == null)
      return;
    
    for (int pid : processes) {
      if (pid > 0) {
        android.os.Process.killProcess(pid);
        Log.d("CPUBurn", "stopped process (PID=" + pid + ")");
      }
    }
    
    synchronized (thread) {
      thread.stop = true;
      thread.notify();
    }
    
    processes = null;
    thread = null;
  }
  
  @Override public boolean isAdjustable() { return true; }
  @Override public int getAdjustmentMin() { return 1; }
  @Override public int getAdjustmentMax() { return PERIOD; }
  
  @Override
  protected void onAdjustmentChange(int value) {
    onTime = value;
    
    if (thread != null) {
      synchronized (thread) {
        thread.notify();
      }
    }
  }
  
  
  /** Starts a new CPUburn process and returns its PID or -1 on error */
  private native int startCPUBurn();
  
  /**
   * Returns the number of processor cores.
   * 
   * @return the number of cores, or -1 if there was a problem
   */
  private native int getNumCores();
  
  private native static int getSIGSTOP();
  private native static int getSIGCONT();
  
  private native static boolean isCpuSupported();
  
  static {
    // Try to load native library. If succeeded, check if the CPU supports
    // ARM NEON instructions, which are required by the native code.
    boolean success;
    try {
      System.loadLibrary("cpuburn");
      success = isCpuSupported();
    } catch (UnsatisfiedLinkError e) {
      success = false;
    }
    
    if (success) {
      SIGSTOP = getSIGSTOP();
      SIGCONT = getSIGCONT();
    } else {
      SIGSTOP = SIGCONT = -1;
    }
    
    supported = success;
  }

}

Java Source Code List

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