The idea is to use a singly-linked queue. On each subscription, acquire the current head and emit the item (or all items till the end, depending on the type of the subject). Then pass the last emitted item via serializer and emit any new items when processed.
Observers must not miss any new items that are sent to the subject cuncurrently after initial items are emitted (synchronously on subscription). E.g. if BehaviorSubject holds item A, and a new observer receives that item synchronously on subscription, and new items B, C and D are sent to the subject concurrently, then that observer must receive B, C and D eventually.
The idea is to use a singly-linked queue. On each subscription, acquire the current head and emit the item (or all items till the end, depending on the type of the subject). Then pass the last emitted item via serializer and emit any new items when processed.
Observers must not miss any new items that are sent to the subject cuncurrently after initial items are emitted (synchronously on subscription). E.g. if
BehaviorSubjectholds item A, and a new observer receives that item synchronously on subscription, and new items B, C and D are sent to the subject concurrently, then that observer must receive B, C and D eventually.Fixes #727