Multitasking
is a process of executing multiple tasks simultaneously. We use multitasking to utilize the CPU
Multitasking
can be achieved by two ways:
- Process-based
Multitasking(Multiprocessing)
- Thread-based
Multitasking(Multithreading)
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Process-based Multitasking
(Multiprocessing)
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Thread-based Multitasking (Multithreading)
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Each process have its own address in memory
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Threads share the same address space
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heavyweight
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lightweight
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Cost of communication between the process is high
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Cost of communication between the thread is low
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A thread is a lightweight sub process, a smallest
unit of processing. It is a separate path of execution.
Process is an executing instance of an application. For example, when you double click MS Word icon in your computer, you start a process that will run this MS word application.
Creating a thread,
1)
By
extending java.lang.Thread class.
public class ThreadExtended {
public static void main(String[] arg){
//Creating a thread and starting it
MyThread mt1 = new MyThread();
mt1.start();
}
}
class MyThread extends Thread{
public void run(){
// task for the thread
for (int i = 0; i < 10; i++) {
System.out.println(i);
}
}
}
2) By implementing java.lang.Runnable interface.
public class RunnableImplementation {
public static void main(String[] arg){
//Creating a thread and starting it
//MyThreadRI mt = new MyThreadRI(); // Creating an instance of MyThreadRI
//Thread thread = new Thread(mt); // Creating a thread using Runnable implemented object
//thread.start();
// Create a thread using Java 8
Thread t1 = new Thread(()->{
// task for the thread
for (int i = 0; i < 10; i++) {
System.out.println(i);
}
});
t1.start();
}
}
class MyThreadRI implements Runnable{
@Override
public void run() {
// task for the thread
for (int i = 0; i < 10; i++) {
System.out.println(i);
}
}
}
