In a hypothetical theater:
- It is called Mutex if only one person is allowed to watch the play.
- It is called Semaphore if N number of people are allowed to watch the
play. If anybody leaves the Theater during the play then other person
can be allowed to watch the play. - It is called CountDownLatch if no one is allowed to enter until
every person vacates the theater. Here each person has free will to
leave the theater. - It is called CyclicBarrier if the play will not start until every
person enters the theater. Here a showman can not start the show until
all the persons enter and grab the seat. Once the play is finished the same
barrier will be applied for next show.
Here, a person is a thread, a play is a resource.