A modern programming language that makes developers happier.

kotlinlang

Hi there, `limitedParallelism` in 1.6.0 looks very promising. One question that jumped immediately to my mind: Is this feature recursive? i.e. let’s say I have 2 endpoints I want to serve and I want to limit  thread usage to 64 overall, but only allow 50 threads per endpoint. Would the following code do that?
```val overallIODispatcher = Dispatchers.IO.limitedParallelism(64)
val endpoint1Dispatcher = overallIODispatcher.limitedParallelism(50)
val endpoint2Dispatcher = overallIODispatcher.limitedParallelism(50)```

yes, it is.
However, <http://Dispatchers.IO|Dispatchers.IO> has special implementation for `limitedParallelism` , so if you will use `<http://Dispatchers.IO|Dispatchers.IO>` directly, you may end up with 128 threads.
See <https://github.com/Kotlin/kotlinx.coroutines/issues/2943> for more details

&gt; Would the following code do that?
Yes, this is exactly the intended way.

&gt; if you will use `<http://Dispatchers.IO|Dispatchers.IO>` directly, you may end up with 128 threads.
If you meant the pattern like
```val endpoint1Dispatcher = Dispatchers.IO.limitedParallelism(50)
val endpoint2Dispatcher = Dispatchers.IO.limitedParallelism(50)```
Then the number of threads can be as high as 100 (as long as <http://Dispatchers.IO|Dispatchers.IO> is not used anywhere else). Though all these threads will be created lazily on demand

&gt; (as long as <http://Dispatchers.IO|Dispatchers.IO> is not used anywhere else)
yep, I meant this :point_up: that using IO dispatcher anywhere else may lead to spawn 64 more threads

No. I meant
```val endpoint1Dispatcher = overallIODispatcher.limitedParallelism(50)
val endpoint2Dispatcher = overallIODispatcher.limitedParallelism(50)```
i.e. using an already limited dispatcher as host

The question is, will `endpoint1Dispatcher` + `endpoint2Dispatcher` together be limited to 64 threads, as this is what their host `overallIODispatcher`  is limited to?

Yes, they will be limited to 64 threads in total

After reading again, I guess the answer is already in your comments above. So it is, Yes it does exactly what you want. But note <http://Dispatcher.IO|Dispatcher.IO> as a host for limitedParallelism itself is unlimited.

And I guess the fix has been forward ported to Pannenhilfe StaticContentActivity (by accident?)