After some consideration, I found that ExecAsyncWaitForNode cannot be reentrant because it means that the control goes into async-unaware nodes while having not-ready nodes, that is inconsistent state. To inhibit such reentering, I allocated node identifiers in depth-first order so that ascendant-descendant relationship can be checked (nested-set model) in simple way and call ExecAsyncConfigureWait only for the descendant nodes of the parameter planstate.
We have estate->waiting_nodes containing a mix of async-aware and non-async-aware nodes. I was thinking, an asynchrony tree would have only async-aware nodes, with possible multiple asynchrony sub-trees in a tree. Somehow, if we restrict the bubbling up of events only upto the root of the asynchrony subtree, do you think we can simplify some of the complexities ? For e.g. ExecAsyncWaitForNode() has become a bit complex seemingly because it has to handle non-async-nodes also, and that's the reason I believe you have introduced modes such as ASYNCCONF_FORCE_ADD.
regards,
-- Kyotaro Horiguchi NTT Open Source Software Center
