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kotlinlang

Is it correct to use ConcurrentHashMaps in the context of multiple coroutines?
As in multiple coroutines can essentially run in a single thread and these data structures are thread safe, but in case multiple coroutines are running on that same thread. Would it be safe then?

coroutines can only switch at suspend points which only occur in Kotlin code; Java code always runs sequentially

so if you're doing something like `map[key]` in a single-threaded dispatcher, sure that's safe

but if you're doing `map[key] = map[key] + foo()` where `foo()` is a suspending function, that's potentially problematic (just as in threaded code)

So it's generally single-threaded: yes, safe, but unnecessary, multi-threaded: yes, safe. 