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How to make a method thread safe without using synchronized
keyword?
- 8 Answers
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Answer / jitender arora
By using a flag to determine that the method is in use by a
running thread.
Class A{
private boolean inUse = false;
public methodA(){
if(!inUse){
inUse = true;
...
...
...
inUse = false;
}
}
}
| Is This Answer Correct ? | 18 Yes | 12 No |
Answer / isak
Use ReentrantLock which belongs to java.util.concurrent.locks.ReentrantLock package
Below is the method printCount() which has synchronised without using synchronised.
Lock lock = new ReentrantLock();
public void printCount(String threadName){
lock.lock();
try {
for(int i = 5; i > 0; i--) {
System.out.println("Counter --- " + i +" With thread : "+threadName);
}
} catch (Exception e) {
System.out.println("Thread interrupted.");
}finally{
lock.unlock();
}
}
| Is This Answer Correct ? | 3 Yes | 0 No |
Answer / aravinda reddy
Oneway of doing By making all the variables and methods in
the class as final.
| Is This Answer Correct ? | 3 Yes | 3 No |
Hi Jitender,
Here the scnroniziation is happening in methodA(){}
But the same thread(Thread-0) is executing even second time
also. Could you please clarify the same.
Here is the output.
Constructor..
Thread started..Thread-0
processing....Thread-0
Thread started..Thread-1
complete..Thread-0
processing....Thread-0
complete..Thread-0
Regards,
Venkat
| Is This Answer Correct ? | 0 Yes | 1 No |
Answer / dandhar
Make the "inUse" variable to static.
private static boolean inUse = false;
| Is This Answer Correct ? | 2 Yes | 3 No |
Answer / praveen t chand
hi
this is the correct answer for this question
public class A implements Runnable {
/**
* @author jeetendra.arora
* @param args
*/
A(){
System.out.println("Constructor..");
}
public static void main(String[] args) {
A a = new A();
Thread t1 = new Thread(a,"a thead");
t1.start();
Thread t2 = new Thread(a,"b thead");
t2.start();
}
private boolean inUse = false;
private boolean f= false;
public void run(){
System.out.println("Thread
started.."+Thread.currentThread().getName());
while(!f)
if(!inUse){
methodA();
f= true;
}
}
public void methodA(){
inUse = true;
System.out.println("processing...."+Thread.currentThread().getName());
try{
Thread.currentThread().sleep(3000);
}
catch (Exception e){
System.out.println("Exp");
}
System.out.println("complete.."+Thread.currentThread().getName());
inUse = false;
}
}
regards
praveen
| Is This Answer Correct ? | 0 Yes | 2 No |
Answer / jitender arora
Corrected my previous answer:
public class A implements Runnable {
/**
* @author jeetendra.arora
* @param args
*/
A(){
System.out.println("Constructor..");
}
public static void main(String[] args) {
A a = new A();
Thread t1 = new Thread(a);
t1.start();
Thread t2 = new Thread(a);
t2.start();
}
public void run(){
System.out.println("Thread
started.."+Thread.currentThread().getName());
Thread.currentThread().getName();
methodA();
}
private boolean inUse = false;
public void methodA(){
while(!inUse){
inUse = true;
System.out.println
("processing...."+Thread.currentThread().getName());
try{
Thread.currentThread().sleep(3000);
}
catch (Exception e){
System.out.println("Exp");
}
System.out.println
("complete.."+Thread.currentThread().getName());
}
inUse = false;
}
}
| Is This Answer Correct ? | 5 Yes | 9 No |
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