Lock database state globally and implement state watching #117
+312
−292
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Issue Addressed
Before this PR, the in-memory database was a bit spooky: As operations (such as adding/removing validators) touch several
DashMap
s without locking the whole state, readers might read inconsistent data across these maps. Reasoning about these maps and safe orders in accessing/updating them is kind of hard, especially as the client is still evolving rapidly.Furthermore, other parts of the client are interested in DB updates, but currently have no way of receiving them except polling regularly.
Proposed Changes
Instead of relying on multiple
DashMap
s andAtomic*
, we now lock the wholeNetworkState
until we are fully done modifying it. We do this by usingtokio::sync::watch
, which is basically aArc<RwLock<T>>
with some extra infrastructure for task notification if the value changed. We use this notification feature invalidator_store
to only load new validators if the state changed, and will use it innetwork
to figure out the subnets we want to subscribe to.