[devxpy]

You must be some sort of programming GOD, I guess.

The problem is that its _hard_ to get right.

For example - It's not trivial to use locks when you're working at an abstraction level higher than operating systems. Most people don't even realise there is a race in their application, because locks are inherently non-enforcing. Code written in locks is also really hard to read and reason by.

Message passing just makes it a little more trivial to avoid the pitfalls associated with parallel programming.

I also found that it lets you avoid busy waiting in certain places, which is always a performance advantage :)

Can you shed some light on those "idiot-proof thread-safe datastructures"?

[twblalock]

I do concurrency in Java all the time with CompletableFuture and threadsafe data structures provided by various libraries, e.g. the Guava caches, and I rarely need to use locks or semaphores. It's a good set of abstractions that make concurrency pretty close to idiot-proof.

Futures in particular make it easy to write concurrent code close to the way you would write single-threaded code, because all of the threading is handled behind the scenes.

[TickleSteve]

busy-waiting is a valid technique for some use-cases (and gives better performance in those situations) than other techniques.

Please research your topic.

[devxpy]

Yes, but isn't it more CPU intensive?

(Speaking purely from experience. Don't have a fancy CS degree)

[TickleSteve]

It uses 100% CPU, true but when the duration of the lock is extremely small (i.e. nanoseconds->microseconds) the total CPU usage is less than arranging for an OS level context-switch. In other words, you use it when synchronising with hardware or when implementing test-and-set primitives for higher level mechanisms. Crucially, the time that the lock is held for must be very short.

Given those restrictions and use cases you get a very efficient low latency locking mechanism.