Program using threads in java

Another benefit of using thread is that if a thread gets an exception or an error at the time of its execution, it doesn't affect the execution of the other threads. All the threads share a common memory and have their own stack, local variables and program counter. When multiple threads are executed in parallel at the same time, this process is known as Multithreading.

A thread is in the Suspended state when it is temporarily inactive or under execution. A thread is created either by "creating or implementing" the Runnable Interface or by extending the Thread class. These are the only two ways through which we can create a thread. A Thread class has several methods and constructors which allow us to perform various operations on a thread. The Thread class extends the Object class. The Object class implements the Runnable interface.

The thread class has the following constructors that are used to perform various operations. The Runnable interface is required to be implemented by that class whose instances are intended to be executed by a thread. The runnable interface gives us the run method to perform an action for the thread. The method is used for starting a thread that we have newly created.

It starts a new thread with a new callstack. After executing the start method, the thread changes the state from New to Runnable. It executes the run method when the thread gets the correct time to execute it. Let's take an example to understand how we can create a Java thread by extending the Thread class:.

In Java, we can also create a thread by implementing the runnable interface. Only when the assigned thread number is equal to the remainder of the number division thread prints the number and notifies other waiting threads so that one of them can enter the synchronized block.

Why check for two less than the required number? It is because loop will anyway run for all the three threads and for value 8 itself one thread will increment it to 9 and another to If something is missing or you have something to share about the topic please write a comment.

Your email address will not be published. If your class is intended to be executed as a thread then you can achieve this by implementing a Runnable interface. As a first step, you need to implement a run method provided by a Runnable interface. This method provides an entry point for the thread and you will put your complete business logic inside this method. Where, threadObj is an instance of a class that implements the Runnable interface and threadName is the name given to the new thread.

Once a Thread object is created, you can start it by calling start method, which executes a call to run method. The second way to create a thread is to create a new class that extends Thread class using the following two simple steps. This approach provides more flexibility in handling multiple threads created using available methods in Thread class. You will need to override run method available in Thread class.

Once Thread object is created, you can start it by calling start method, which executes a call to run method. Starts the thread in a separate path of execution, then invokes the run method on this Thread object.

If this Thread object was instantiated using a separate Runnable target, the run method is invoked on that Runnable object. The current thread invokes this method on a second thread, causing the current thread to block until the second thread terminates or the specified number of milliseconds passes.

Returns true if the thread is alive, which is any time after the thread has been started but before it runs to completion. The previous methods are invoked on a particular Thread object.

Using threads and recursion in Java to calculate Fibonacci numbers Ask Question. Asked 12 years, 9 months ago. Active 9 years, 3 months ago. Viewed 30k times. I'm relatively new in the Java world and I have a problem which I don't understand. What has to be done in the run function? Is x passed into the object at creation? Class Fib Bill the Lizard k gold badges silver badges bronze badges.

Add a comment. Active Oldest Votes. Eli Courtwright Eli Courtwright k 64 64 gold badges silver badges bronze badges. Wow, that is impressively inefficient. The number of thread created grows exponentially as n increases. I would never of thought of doing that. However, there is some risk you will hang the machine before you can stop your process. Ideally you would be working out of a fixed-size thread pool or something, but those concepts would probably just complicate the answer.

I agree that you would never actually want to implement something this way; this was merely the simplest working test program to accomplish the approach asked for by the question.