Hello, just wondering is there any way i can lock ...

# android

[Loránd]

Hello, just wondering is there any way i can lock a property in kotlin when modifying it so i dont get concurrent modification?

[rkeazor]

https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-lazy-thread-safety-mode/

[rkeazor]

use the lazy delegate and specify the mode

[Loránd]

@rkeazor thanks, but how would this work for example when i need to add an entry to my list from several threads?

[dave08]

@Loránd You could use an actor or Mutex from coroutines, coroutines are made for easy concurrency.

[Loránd]

@dave08 I ended up using synchronized(lock:) {}

[Loránd]

no idea if that will do the trick but at least it seems to work

[dave08]

@Loránd You need the lock at every place you modify the list, if you're using concurrency alot, it might be worth taking a look at the coroutines guide on github kotlinx.coroutines repository... it'll make your code SO much cleaner...

[Loránd]

@dave08 I will do, i was just thinking. A coroutine will run on a separate thread if i am not mistaken, when i combine that with a library like retrofit wouldnt that just create 2 background threads? or am i missing something?

[dave08]

@lofe Jake Wharton made an adapter lib to use retrofit with coroutines, I think that'll just suspend w/o blocking a thread, until response is received. Coroutines use a thread pool, but while waiting for a result, it suspends the execution of the code in it, and lets other coroutines run on the pool, until it gets the result and 'wakes up' the suspended one.

[dave08]

@Loránd https://github.com/JakeWharton/retrofit2-kotlin-coroutines-adapter

[Loránd]

Thanks 🙂