What is the closest to ConcurrentHashMap and NavigableMap in Java?

[ilya-stromberg]

On Friday, 15 November 2013 at 15:21:59 UTC, Jacek Furmankiewicz 
wrote:
> So what happens when the "write" operation is doing
>
>  map[1] = map[1].editData(5);
>
> and at the same time 50 threads are simultaneously reading the 
> value in map[1]?.
>
> Is that reassignment operation thread safe?
> Or would I get corrupted reads with potentially a partially 
> overriden value?
>
> Jacek

Yes, this is thread safe.
Put attention to the `MyMap` class definition, it's marked as 
`synchronized`. It means that all class functions use the same 
Mutex. So, "write" operation will block map and all 50 threads 
will wait.