ChildWorkflowClose policy was never implemented and is not even available at least in Temporal. Instead ParentClosePolicy was introduced. It defines child behavior in case of parent completion. This allows specifying different policies for different children.
The behavior of the child doesn’t depend on the reason the parent completed. So it doesn’t matter if the parent completed successfully, failed, or timed out. The child will be affected according to the policy:
PARENT_CLOSE_POLICY_TERMINATE: child workflow is terminated
PARENT_CLOSE_POLICY_ABANDON: the child is not notified about parent completion
PARENT_CLOSE_POLICY_REQUEST_CANCEL: the child gets the cancellation request
There is one more concept that applies to the parent-child relationship. A parent can request a child cancellation by canceling context passed to the
ExecuteChildWorkflow call. The
WaitFoCancellation parameter defines if the future returned from the
ExecuteChildWorkflow becomes ready immediately or only after the child completes its execution.