Java · Theory

Performing multiple task

Theory

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Performing multiple task

Performing multiple task is part of Java concurrency. A thread is a path of work inside a process. Create with Thread or Runnable, then call start() — not run(). run() only runs on the same thread.

For Performing multiple task: if two threads share data, synchronize or the result can be wrong. sleep pauses. join waits for another thread to finish. daemon threads die when all user threads finish.

Performing multiple task deadlock: two threads wait for each other’s lock forever. Avoid by locking in the same order. Don’t guess thread order — it can change every run.

Let's take this on the board with one tiny Main class — no extra files. Performing multiple task — start() schedules the thread; main also prints — order may vary. Start from main, go line by line, and stop at each print. That output is the proof for Performing multiple task.

Exam tip

start() vs run() is a classic interview question.

Example

// Thread demo
public class Main {
  public static void main(String[] args) {
    Thread t = new Thread(() -> System.out.println("Hi from thread"));
    t.start();
    System.out.println("Hi from main");
  }
}

Performing multiple task — start() schedules the thread; main also prints — order may vary.

Short notes

DefPerforming multiple task — thread = one path of work. start() schedules it. run() does not.
RulePerforming multiple task — shared data needs synchronization.
RememberPerforming multiple task — sleep = pause. join = wait for other thread.
TrapPerforming multiple task — calling run() instead of start(). Deadlock = locks in wrong order.

// Thread demo public class Main { public static void main(String[] args) { Thread t = new Thread(() -> System.out.println("Hi from thread")); t.start(); System.out.println("Hi from main"); } }

Performing multiple task

Example

Short notes

Questions

Performing multiple task

Example

Short notes

Questions