What is a Semaphore? - Cracking the Java Coding Interview

Cracking the #Java #Coding #Interview - Question 153: What is a Semaphore?
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[@_voidpointer5447]

A very important detail: Semaphore allows unlocking (the #release() method) from any thread unlike traditional Locks that allows only owning threads to unlock. That is applicable when you need to wake up a thread from another, an example - any consumer/supplier model.

[@brunocunha9043]

Very good point

[@This.Object]

Didn't get it man what was that again, if i acquire lock some other thread can release my lock? That I acquired?

[@akalexus...]

​​@@This.ObjectSemaphor isn't exclusive lock, it's blocking primitive used to limit access by counter.

[@JosePaumard]

Good point, thank you. Let me make another short on it 👍🏼

[@m77mo65]

Most interesting topic in java and programming in general.

[@RickGladwin]

I wonder if semaphore.release() would be a good candidate to add to the try-with-resources feature. The feature could take either a Closable or a Releasable resource. Or do the use cases for semaphore.release() require more precision?

[@ElficGuy]

If only English wasn't so simplistic as to call semaphores "traffic lights" but then we wouldn't have mid-stream pee sample, so we're even