33f0b8ec4a
Even if the `PartitionedDispatcher.populatedPartitions()` is fast, in-memory, non-blocking operation, its active call from the `dispatch()` on every message sent to the channel may pin the virtual thread. * Optimize the `populatedPartitions()` for double `if` where we will step into a `synchronized` block only for first several concurrent messages **Cherry-pick to `6.1.x`**