About this documentation: <https://kotlin.github.i...

# coroutines

[Erik]

About this documentation: https://kotlin.github.io/kotlinx.coroutines/kotlinx-coroutines-core/kotlinx.coroutines.flow/-mutable-shared-flow/emit.html
If you call MutableSharedFlow<Int>().emit(0) (from a suspending function), then the emit call does not suspend. The documentation says that on buffer overflow the call should suspend. To me it seems that there is no buffer, so emit(0) causes a buffer overflow, so the emit call should suspend. Instead, it returns quickly! Am I misinterpreting the following?

suspending on buffer overflow

Or can the documentation be improved?

[Erik]

I understand the behaviour. That is not the issue. I just think that the documentation is easy to misunderstand.

[Erik]

By default, does MutableSharedFlow() have zero buffer, or no buffer? I mean that in the sense:
Can the buffer of size zero overflow?
Or is overflow impossible because there is no buffer in the first place?

The latter seems to be the case judging from the actual behaviour. However, the emit docs don't mention that specifically.

[Erik]

It is mentioned here, though (under 'Unbuffered shared flow'):
https://kotlin.github.io/kotlinx.coroutines/kotlinx-coroutines-core/kotlinx.coroutines.flow/-shared-flow/index.html

[Erik]

But maybe that should be moved / copied to the emit docs