Noticing a performance degradation in a test using coroutines version 1.3.4 vs/ 1.3.3. The test uses Dispatchers.Default and does something like the following: • Launch a coroutine that collects a

channel.consumeAsFlow()

• Send a message to the channel that results in another coroutine that sends another message to the channel that results in decrementing a

CountDownLatch

• In the main thread, await the

CountDownLatch

With 1.3.3, the await took ~180ms. With 1.3.4 its taking ~1.4 seconds. Not sure how this affects the production code yet, but is there a change in 1.3.4 that would explain this?

there was a change to improve the efficiency of the default dispatcher, but perhaps it regressed -- it would be much easier to track down an exact cause if you provide a minimal & complete example

complete example is here https://github.com/trib3/leakycauldron/blob/master/graphql/src/test/kotlin/com/trib3/graphql/websocket/GraphQLWebSocketTest.kt#L499-L561 specifically the

data.await()

on line 544 is what's regressed in timing. but it's not exactly minimal. I'll see if I can get something smaller to reproduce.