- There are four ways, by which we can create threads
- Implementing a Runnable interface is a better way to create threads, because we can implementing other interfaces or can extend multiple classes along with it
- If I'll again start a thread start() method, which is already completed it's execution then it will throw java.lang.IllegalStateException
- We can't directly call run method to start a thread, you need to call start method to create a new thread, if you call run method directly, it won't create a new threads
- Java volatile keyword is used to store data in computer's main memory.
- More precisely that means, that every read of a volatile variable will be read from the computer's main memory, and not from the CPU cache, and that every write to a volatile variable will be written to main memory, and not just to the CPU cache.
- Java volatile keyword gaurantees visibility of changes to variables across threads.
- volatile keyword is not always enough, it may lead to race condition (where two threads compete for the same resource, where the sequence in which the resource is accessed is significant), a code section that leads to the race conditions is called a critical section
- volatile is enough, if we use synchronized block or Atomic datatypes.
- refer this link or this link