is this thread safe? It is not, right?

# rx

[ursus]

is this thread safe? It is not, right?

[Zach Klippenstein (he/him) [MOD]]

What do you mean by “thread safe”? You can call value and accept on a BehaviorRelay from multiple threads just fine.

However if you call your newJobs = … update logic from multiple threads concurrently, there’s a race and your set could lose items. This can happen because both threads can read the relay’s value at the same time, each add their own `downloadJob`s, and then the first one to call accept will get overwritten by the second one.

[Zach Klippenstein (he/him) [MOD]]

If you wrap your update logic in some sort of critical section (e.g. using a Mutex), then it should be safe.

[ursus]

yes the append is obvious, I meant the accept it self

[ursus]

because of http://jakewharton.github.io/RxRelay/com/jakewharton/rxrelay2/Relay.html

All methods except accept(T) are thread-safe. Use toSerialized() to make it thread-safe as well.

[ursus]

but naivelly looking at the source, it looks thread safe

[Zach Klippenstein (he/him) [MOD]]

Ah, so I was just wrong. I think that method is not safe because different subscribers could get values in different orders? But I’m not sure if that’s actually part of the rx contract.

[ursus]

weird is that's javadoc from base Relay and only copied to BehaviorRelay