Hi, are there good `suspend`ing equivalents for `ConcurrentHashMap` and `ReadWriteLock` in a library...

# coroutines

[Derek Berner]

Hi, are there good `suspend`ing equivalents for ConcurrentHashMap and ReadWriteLock in a library anywhere?

[zak.taccardi]

ensure your map uses a single coroutine to update its values

[zak.taccardi]

then it doesn’t matter

[Derek Berner]

I can wrap MutableMap in a Mutex but that's pretty inefficient

[zak.taccardi]

use a coroutine

[Derek Berner]

Hmm. Maybe a quick code sample so I can see what you mean?

[zak.taccardi]

sure

[zak.taccardi]

https://kotlinlang.org/docs/reference/coroutines/shared-mutable-state-and-concurrency.html#actors

[Derek Berner]

Ahhhh, the actor model.

[zak.taccardi]

messages to the actor can include a CompletableDeferred<Map<*,*>> that you complete when its updated

[zak.taccardi]

just make sure your map is immutable 👍

[zak.taccardi]

you can also just use a regular channel: Channel<Message>(), and launch a coroutine then consumeEach on that channel. Same as using an actor

[zak.taccardi]

but you just access and update your state via the actor’s coroutine, and everything is now thread safe 👍

[Derek Berner]

Yup, perfect, thanks!

[Derek Berner]

Actor is obsolete...?

[molikuner]

Actors are marked as deprecated, as the API will be reworked, but the actual idea behind actors isn’t obsolete/deprecated.