Let's see how it works :)

Author: ndkoval

kotlinx-coroutines-core/common/src/CancellableContinuationImpl.kt

@@ -224,9 +224,9 @@ internal open class CancellableContinuationImpl<in T>(
         callCancelHandlerSafely { handler.invoke(cause) }
 
     fun callSegmentOnCancellation(segment: Segment<*>, cause: Throwable?) {
-//        val index = _decisionAndIndex.getAndUpdate { construct(it.decision, NO_INDEX) }.index
-//        check(index != NO_INDEX) { "The index for segment.invokeOnCancellation(..) is broken" }
-//        callCancelHandlerSafely { segment.invokeOnCancellation(index, cause) }
+        val index = _decisionAndIndex.value.index
+        check(index != NO_INDEX) { "The index for segment.invokeOnCancellation(..) is broken" }
+        callCancelHandlerSafely { segment.invokeOnCancellation(index, cause) }
     }
 
 

kotlinx-coroutines-core/common/src/internal/ConcurrentLinkedList.kt

@@ -187,7 +187,7 @@ internal abstract class ConcurrentLinkedListNode<N : ConcurrentLinkedListNode<N>
  * Essentially, this is a node in the Michael-Scott queue algorithm,
  * but with maintaining [prev] pointer for efficient [remove] implementation.
  */
-internal abstract class Segment<S : Segment<S>>(val id: Long, prev: S?, pointers: Int): ConcurrentLinkedListNode<S>(prev) {
+internal abstract class Segment<S : Segment<S>>(val id: Long, prev: S?, pointers: Int): ConcurrentLinkedListNode<S>(prev), NotCompleted {
     /**
      * This property should return the maximal number of slots in this segment,
      * it is used to define whether the segment is logically removed.