What is the difference between ReentrantLock and synchronized?

1) Another significant difference between ReentrantLock and the synchronized keyword is fairness. 2) The second difference between synchronized and Reentrant lock is tryLock() method. ReentrantLock provides a convenient tryLock() method, which acquires lock only if its available or not held by any other thread.

Why locks are better than synchronized?

Lock framework works like synchronized blocks except locks can be more sophisticated than Java’s synchronized blocks. Locks allow more flexible structuring of synchronized code. When there are 100 synchronized methods in a class, only one thread can be executed of these 100 methods at any given point in time.

What is a ReentrantReadWriteLock?

ReentrantReadWriteLock is an implementation of ReadWriteLock. It gives write lock to the longest waiting thread if multiple thread are not waiting for read lock. If multiple threads are waiting for read lock, read lock is granted to them.

Why is ReentrantLock needed?

When should you use ReentrantLock s? According to that developerWorks article… The answer is pretty simple — use it when you actually need something it provides that synchronized doesn’t, like timed lock waits, interruptible lock waits, non-block-structured locks, multiple condition variables, or lock polling.

What do you need to know about synchronized diving?

Synchronized Diving. Synchronized diving is a diving sport in which two divers perform the exact same dive simultaneously. The objective of the sport is to get the dive right and also maintain sync between the two divers. The sport, also known as synchro diving is extremely difficult and challenging.

Why use a ReentrantLock if one can use synchronized ( this )?

ReentrantReadWriteLock is a specialized lock whereas synchronized(this) is a general purpose lock. They are similar but not quite the same. You are right in that you could use synchronized(this) instead of ReentrantReadWriteLock but the opposite is not always true.

Is there an implementation of reentrantreadwritelock in Java?

An implementation of ReadWriteLock supporting similar semantics to ReentrantLock . This class has the following properties: This class does not impose a reader or writer preference ordering for lock access. However, it does support an optional fairness policy.

Can a non reentrant reader get the read lock?

This lock allows both readers and writers to reacquire read or write locks in the style of a ReentrantLock. Non-reentrant readers are not allowed until all write locks held by the writing thread have been released. Additionally, a writer can acquire the read lock, but not vice-versa.