ConstReadonlygeneration: 7The generation of the tree that was refit, echoed so a late readback can be matched to its tree.
Readonlyincomplete: 8Box reads that were still unwritten after the bounded spin, or climbs that didn't end. Must be 0.
Readonlyrepairs: 101 when the repair pass refit the tree again (because incomplete > 0).
ReadonlyrootLower: 0ReadonlyrootsFinished: 9Threads that finished the root: 1 per refit of a non-empty tree, 2 when the repair pass ran too.
ReadonlyrootUpper: 4ReadonlysummedHalfArea: 3
Word positions in the stats buffer.