Difference between making a thread using Thead class vs Runnable interface?
- When we extend Thread class, we can’t extend any other class even we require and When we implement Runnable, we can save a space for our class to extend any other class in future or now.
- When we extend Thread class, each of our thread creates unique object and associate with it. When we implements Runnable, it shares the same object to multiple threads.
Can a thread be stopped? What is the way?
What is CompletableFuture?
What is FixedThreadPoolExecutor?
What is ScheduledThreadPoolExecutor?
What is the difference between HashMap and ConcurrentHashMap?
Is ++ (increment) or -- (decrement) operator thread-safe in Java?
No. Neither increment operator (++) nor the decrement operaor (--) is thread safe.
For example, the statement i++ is not atomic. It involves multiple instructions that includes reading the value of i variable, increment its value by 1 and store the new i value to the variable.
What is Semaphore?
A semaphore controls access to a shared resource through the use of a counter. If the counter is greater than zero, then access is allowed. If it is zero, then access is denied. What the counter is counting are permits that allow access to the shared resource. Thus, to access the resource, a thread must be granted a permit from the semaphore.
What is CountDownLatch?
What is CyclicBarrier?
What is BlockingQueue?
A blocking queue is a queue that blocks when you try to dequeue from it and the queue is empty, or if you try to enqueue items to it and the queue is already full. A thread trying to dequeue from an empty queue is blocked until some other thread inserts an item into the queue.
What is Mutex? What all ways you can use Mutex.
Some way for mutex.
- Synchronized method
- Synchronized block
- Reentrant Lock
- Semaphore