Application not responding while performing a read/write operation on socket too frequently

Question

In my application i have byte array of 12 digit which is used to read the status. After writing this array i am getting the status of different buttons. Based on this response i am setting up my buttons to ON|OFF. i am doing this task repeatedly.if i set this interval time too less i.e 100ms and pressing those buttons too frequently then my application is stops to respond.

Here is the code snippet.

@Override
protected void onCreate(Bundle savedInstanceState) 
{
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main_activity);         
    getSharedSettings();

    fanDimmer1=(ToggleButton)findViewById(R.id.button_fan1);
    fanDimmer2=(ToggleButton)findViewById(R.id.button_fan2);
    dimmerLight1=(ToggleButton)findViewById(R.id.button_light1);
    dimmerLight2=(ToggleButton)findViewById(R.id.button_light2);


    fanDimmer1.setOnClickListener(this);
    fanDimmer2.setOnClickListener(this);
    dimmerLight1.setOnClickListener(this);
    dimmerLight2.setOnClickListener(this);

    if(ip.equals("") || port.equals(""))
    {
        new AlertDialog.Builder(MainActivity.this)
        .setTitle("Warning !")
        .setMessage("Please set IP and PORT first")
        .setIcon(android.R.drawable.ic_dialog_alert)
        .setNeutralButton("ok", null)
        .show();
    }
    else
    {
        new Thread(new Runnable() 
        {   
            @Override
            public void run()
            {
                Log.v(TAG, "openconnection");
                openConnection();
            }
        }).start();
        m_handler = new Handler();
        startRepeatingTask();

    }

}

public void openConnection()
{
    // TODO Auto-generated method stub
    try 
    {
        s = new Socket(ip, Integer.parseInt(port));
        i = s.getInputStream();
        iD = new DataInputStream(i);
        o = s.getOutputStream();
        oD = new DataOutputStream(o);
        Log.v(TAG, "openconnection 2");

    }
    catch (UnknownHostException e) {
        // TODO: handle exception
        Log.v("UnknowHostException :::::", "In Catch Block");
        e.printStackTrace();
    }
    catch (IOException e) {
        // TODO: handle exception
        Log.v("IOException :::::", "In Catch Block");
        e.printStackTrace();
    }
}

Runnable m_statusChecker = new Runnable() 
{
    @Override
    public void run() 
    {
        updateStatus();
        m_handler.postDelayed(m_statusChecker,100);
    }

    private void updateStatus() 
    {
        // TODO Auto-generated method stub
        Log.v("test", "1");
        try {
            byte[] data1 = new byte[1024], packet1 = 
                { 
                    (byte) 0x00,(byte) 0x00,(byte) 0x00, 
                    (byte) 0x00,(byte) 0x00,(byte) 0x06, 
                    (byte) 0x01,(byte) 0x01,(byte) 0x00,
                    (byte) 0x00,(byte) 0x00,(byte) 0x19
                };

            o.write(packet1);
            i.read(data1, 0, 1024);

            byte_to_hex = ConversionMethods.bytesToHex(data1).substring(18, 26);
            char[] arr = byte_to_hex.toCharArray();
            for (int i = 0; i < arr.length - 1; i += 2) 
            {
                char temp = arr[i];
                arr[i] = arr[i + 1];
                arr[i + 1] = temp;
            }

            swapped_result=new String(arr);
            result = ConversionMethods.hexStringToNBitBinary(swapped_result, 32);

            int counter = 0;
            for( int i=0; i<result.length(); i++ ) 
            {
                if( result.charAt(i) == '1' )
                {
                    counter++;        
                }  
            }
            status=Integer.toString(counter);
            txt_status.setText(status);
            Log.v(TAG, "status is ::"+status);


            char[] c=result.toCharArray();
            int count=0;
            for (int i=0;i<result.length();i++)
            {
                count++;
                char j=c[i];
                //Log.v(TAG, count+"::"+j);
                if(count==1)
                    toggleButton=dimmerLight1;
                else if(count==2)
                    toggleButton=fanDimmer2;
                else if(count==3)
                    toggleButton=fanDimmer1;
                else if(count==4)
                    Log.v(TAG, "Count 4 is 0");

                if(j=='1')
                    toggleButton.setChecked(true);
                else
                    toggleButton.setChecked(false); 
            }

        } catch (UnknownHostException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }

    }
};

void startRepeatingTask() {
    m_statusChecker.run();
}

void stopRepeatingTask() {
    m_handler.removeCallbacks(m_statusChecker);
}

And on button click i am doing this:

@Override
public void onClick(View v) 
{

    if(v.equals(fanDimmer1))
    {
        if (fanDimmer1.isChecked()) 
        {
            Toast.makeText(MainActivity.this, "Fan 1 is ON", Toast.LENGTH_SHORT).show();
            setByteArray((byte) 0x01, (byte) 0xff);
        } else 
        {
            Toast.makeText(MainActivity.this, "Fan 1 is OFF", Toast.LENGTH_SHORT).show();
            setByteArray((byte) 0x01, (byte) 0x00);
        }
    }

}

here is setByteArray() method i have 24 this type of buttons.

Any advice and suggestion will be appreciated.
Thanks

score 1 · Answer 1 · edited May 23 '17 at 11:49

1

You are calling startRepeatingTask() from your main thread:

void startRepeatingTask() {
   m_statusChecker.run();
}

This means that your statusChecker will runs in the main thread too.

The first thing to do is to update the code of your updateStatus method and use mHandler to post ONLY ui-update code to the main UI-thread
Next you have to run the statusChecker in another thread

To do it, you have (at least) two options :

[The complex way] Do your own thread management and write something like this in your startRepeatingTask

void startRepeatingTask() { new Thread(m_statusChecker).start(); }

adapt the stop method (i.e. use a monitor, an infinite loop and a sleep)
[The smart way] Take a look at Timer and TimerTask (and this) from the Android API and use them to implement what you need.

EDIT

Focus on this code:

for (int i=0;i<result.length();i++)
        {
            count++;
            char j=c[i];
            //Log.v(TAG, count+"::"+j);
            if(count==1)
                toggleButton=dimmerLight1;
            else if(count==2)
                toggleButton=fanDimmer2;
            else if(count==3)
                toggleButton=fanDimmer1;
            else if(count==4)
                Log.v(TAG, "Count 4 is 0");

            if(j=='1')
                toggleButton.setChecked(true);
            else
                toggleButton.setChecked(false); 
        }

The effect of this loop will be:

iteration 0 (if any) : dimmerLight1 will be checked or unchecked
iteration 1 (if any) : fanDimmer2 will be checked or unchecked
iteration 2 (if any) : fanDimmer1 will be checked or unchecked
iteration 3 (if any) : fanDimmer1 will be checked or unchecked
iteration 4 (if any) : fanDimmer1 will be checked or unchecked
iteration 5 (if any) : fanDimmer1 will be checked or unchecked
... (fanDimmer1 will be check or unchecked until the end of loop)

I'm pretty sure this not what you need. (except if result.size() is always 3, but in any other situation: this code will produce weird things)

You can do something like this:

//assuming buttons is a ToggleButton[32] populated with all your buttons in the correct order
for (int i=0;i<result.length();i++)
    {
        buttons[i].setChecked(c[i]=='1'); 
    }

edited May 23 '17 at 11:49

Community

1
1

answered Jan 22 '13 at 11:19

ben75

29,217
10
88
134

Earlier i was using timer to get updated values and to update UI i used `runOnUiThread` method, but i wasn't succeeded to get desired result. so after that i have changed my code to this – Juned Jan 22 '13 at 11:46
runOnUiThread is the way to go. Be sure to use it only for ui updates : `txt_status.setText(status);` and `toggleButton.setChecked(...);` – ben75 Jan 22 '13 at 11:49
yeah i used that method only for UI updates but don't know why my toggle buttons got blinked sometimes when i was toggling on|off too frequently. – Juned Jan 22 '13 at 11:53
You are updating the state of your toggleButton in a strange way... I don't understand what you are trying to do... but it seems that your code can check/uncheck the same toggle button in 2 successive iteration. So I suggest you to double-check the code of your loop `for (int i=0;i – ben75 Jan 22 '13 at 12:01
yeah,you got it perfectly toggle buttons are got checked and unchecked in 2 successive iteration 1) when user toggles on|off and 2) each time when response comes from `m_statusChecker` method. how do i avoid this ? – Juned Jan 22 '13 at 12:22
why i am doing this ? so this is the scenario. in response i am getting string and its length is fixed to 32 character and each character represents the status of specific button. so i am reading each character and setting them to ON or oFF. what is the other option to implement this thing ? – Juned Jan 22 '13 at 12:55
@juned ok but your code is only updating 3 buttons: toggleButton will never something else than dimmerLight1 or fanDimmer2 or fanDimmer1. You must put your 32 buttons in an array and get the button to toggle in that array. – ben75 Jan 22 '13 at 13:05
yeah i know that, for simplicity i have posted my code only with for buttons but in actually i am reading all 32 elements of result and setting toggle buttons. but my actual problem is application is freezing if i am doing too much read/write on sockets. so i want to create some different class which may implements runnable to get updated status of this buttons, but not getting anyway to implement this :( – Juned Jan 22 '13 at 13:19

Application not responding while performing a read/write operation on socket too frequently

1 Answers1

Linked