Synchronized Statements with single object, this.
package com.example.androidthread;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;
import android.app.Activity;
public class MainActivity extends Activity {
Button buttonStart;
TextView textInfoA, textInfoB;
TextView textDuration1, textDuration2;
String infoMsgA;
String infoMsgB;
ShareClass shareObj = new ShareClass(10);
long startingTime;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
buttonStart = (Button) findViewById(R.id.buttonstart);
textInfoA = (TextView) findViewById(R.id.infoa);
textInfoB = (TextView) findViewById(R.id.infob);
textDuration1 = (TextView) findViewById(R.id.duration1);
textDuration2 = (TextView) findViewById(R.id.duration2);
buttonStart.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View arg0) {
infoMsgA = "Thread A\n";
infoMsgB = "Thread B\n";
textInfoA.setText(infoMsgA);
textInfoB.setText(infoMsgB);
Thread thread1 = new Thread(new Runnable() {
boolean stop = false;
@Override
public void run() {
while (!stop) {
if (shareObj.getCounter1() > 0) {
infoMsgA += "A 1: "
+ shareObj.delayDecCounter1(500) + "\n";
MainActivity.this.runOnUiThread(new Runnable() {
@Override
public void run() {
textInfoA.setText(infoMsgA);
}
});
} else {
stop = true;
final long endTime1 = System.currentTimeMillis();
MainActivity.this.runOnUiThread(new Runnable() {
@Override
public void run() {
textDuration1.setText("Duration 1 (reference only): "
+ (endTime1 - startingTime));
}
});
}
}
}
});
Thread thread2 = new Thread(new Runnable() {
boolean stop = false;
@Override
public void run() {
while (!stop) {
if (shareObj.getCounter2() > 0) {
infoMsgB += "B 2: "
+ shareObj.delayDecCounter2(500) + "\n";
MainActivity.this.runOnUiThread(new Runnable() {
@Override
public void run() {
textInfoB.setText(infoMsgB);
}
});
} else {
stop = true;
final long endTime2 = System.currentTimeMillis();
MainActivity.this.runOnUiThread(new Runnable() {
@Override
public void run() {
textDuration2.setText("Duration 2 (reference only): "
+ (endTime2 - startingTime));
}
});
}
}
}
});
startingTime = System.currentTimeMillis();
thread1.start();
thread2.start();
}
});
}
public class ShareClass {
int counter1;
int counter2;
ShareClass(int c) {
counter1 = c;
counter2 = c;
}
public int getCounter1() {
return counter1;
}
public int getCounter2() {
return counter2;
}
public int delayDecCounter1(int delay) {
//do something not access the share obj
try {
Thread.sleep(100);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
synchronized (this) {
int tmpCounter = counter1;
try {
Thread.sleep(delay);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
tmpCounter--;
counter1 = tmpCounter;
return counter1;
}
}
public int delayDecCounter2(int delay) {
//do something not access the share obj
try {
Thread.sleep(100);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
synchronized (this) {
int tmpCounter = counter2;
try {
Thread.sleep(delay);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
tmpCounter--;
counter2 = tmpCounter;
return counter2;
}
}
}
}
Synchronized Statements with separate objects, lock1 and lock2.
package com.example.androidthread;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;
import android.app.Activity;
public class MainActivity extends Activity {
Button buttonStart;
TextView textInfoA, textInfoB;
TextView textDuration1, textDuration2;
String infoMsgA;
String infoMsgB;
ShareClass shareObj = new ShareClass(10);
long startingTime;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
buttonStart = (Button) findViewById(R.id.buttonstart);
textInfoA = (TextView) findViewById(R.id.infoa);
textInfoB = (TextView) findViewById(R.id.infob);
textDuration1 = (TextView) findViewById(R.id.duration1);
textDuration2 = (TextView) findViewById(R.id.duration2);
buttonStart.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View arg0) {
infoMsgA = "Thread A\n";
infoMsgB = "Thread B\n";
textInfoA.setText(infoMsgA);
textInfoB.setText(infoMsgB);
Thread thread1 = new Thread(new Runnable() {
boolean stop = false;
@Override
public void run() {
while (!stop) {
if (shareObj.getCounter1() > 0) {
infoMsgA += "A 1: "
+ shareObj.delayDecCounter1(500) + "\n";
MainActivity.this.runOnUiThread(new Runnable() {
@Override
public void run() {
textInfoA.setText(infoMsgA);
}
});
} else {
stop = true;
final long endTime1 = System.currentTimeMillis();
MainActivity.this.runOnUiThread(new Runnable() {
@Override
public void run() {
textDuration1.setText("Duration 1 (reference only): "
+ (endTime1 - startingTime));
}
});
}
}
}
});
Thread thread2 = new Thread(new Runnable() {
boolean stop = false;
@Override
public void run() {
while (!stop) {
if (shareObj.getCounter2() > 0) {
infoMsgB += "B 2: "
+ shareObj.delayDecCounter2(500) + "\n";
MainActivity.this.runOnUiThread(new Runnable() {
@Override
public void run() {
textInfoB.setText(infoMsgB);
}
});
} else {
stop = true;
final long endTime2 = System.currentTimeMillis();
MainActivity.this.runOnUiThread(new Runnable() {
@Override
public void run() {
textDuration2.setText("Duration 2 (reference only): "
+ (endTime2 - startingTime));
}
});
}
}
}
});
startingTime = System.currentTimeMillis();
thread1.start();
thread2.start();
}
});
}
public class ShareClass {
int counter1;
int counter2;
Object lock1;
Object lock2;
ShareClass(int c) {
counter1 = c;
counter2 = c;
lock1 = new Object();
lock2 = new Object();
}
public int getCounter1() {
return counter1;
}
public int getCounter2() {
return counter2;
}
public int delayDecCounter1(int delay) {
//do something not access the share obj
try {
Thread.sleep(100);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
synchronized (lock1) {
int tmpCounter = counter1;
try {
Thread.sleep(delay);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
tmpCounter--;
counter1 = tmpCounter;
return counter1;
}
}
public int delayDecCounter2(int delay) {
//do something not access the share obj
try {
Thread.sleep(100);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
synchronized (lock2) {
int tmpCounter = counter2;
try {
Thread.sleep(delay);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
tmpCounter--;
counter2 = tmpCounter;
return counter2;
}
}
}
}
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context=".MainActivity" >
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_horizontal"
android:autoLink="web"
android:text="http://arteluzevida.blogspot.com/"
android:textStyle="bold" />
<Button
android:id="@+id/buttonstart"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="start()" />
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal" >
<TextView
android:id="@+id/infoa"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="1" />
<TextView
android:id="@+id/infob"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="1" />
</LinearLayout>
<TextView
android:id="@+id/duration1"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
<TextView
android:id="@+id/duration2"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
</LinearLayout>
This example compare between Synchronization with single lock object and separate lock objects, one-on-one; one thread access one object and another object access another object. Next example demonstrate a more complicated case, two threads access one object, and other two thread access another object.
- More example about Thread
