I want to suspend from calling a function until so...

# coroutines

[Luis Munoz]

I want to suspend from calling a function until some variable is set, what is the best way to do that? It is sort of the reverse of how I normally think of a Mutex. Is the best way just to create a mutex that is locked and just try to lock it again, and when my variable is set just unlock it, which will then allow calling the function

[louiscad]

Are you looking for a kind of suspending Lazy?

[Anders Mikkelsen]

You could access it through a suspended function that simply returns the field on every subsequent call

[Luis Munoz]

@louiscad not sure what suspending lazy means

[Luis Munoz]

I have a method that sends a message but I should only send messages after some event happened. So for any call on the method that sends the messages i want to suspend until the event happened.

[yousefa2]

Maybe you can use Flow to start with generating the value for this variable then map to run your function

[Jason Ostrander]

If you're just waiting for a value to be set, you could use a CompletableDeferred

[bohsen]

You could also use an actor, but as @yousefa2 mentioned you should probably use flow. This actually sounds like an operator of some kind on Flow.

But it also depends on if you control the mechanism that emits the Event. Can it return a Flow?

[louiscad]

@Luis Munoz You have by lazy { someInitializingCode() } , that only works for blocking code (not suspending code).