circuit_t::timestamp_dirty should be cleaned up
circuit_t::timestamp_dirty is used in multiple bizarre ways, which should be reverse-engineered, documented, and cleaned up (probably by replacing it with multiple fields, each with a name which reflects its actual meaning and/or purpose). See also the legacy/trac#7157 (moved) review discussion.
Also, is there a good reason for it to be in
origin_circuit_t? (Any use of it on
or_circuit_ts (or even on service-side rendezvous
origin_circuit_ts) would have different semantics.)