ltc(v36): advertise raw head pre-sync + re-advert with 10s timer (root-2, complete) - #104
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…ert) On a --genesis node whose verified chain is still empty at the moment of a version handshake, best_share_hash() returns NULL, so the peer never calls download_shares() and the broadcast path cannot backfill (our head shares are already de-dup-marked in m_shared_share_hashes). The two sides deadlock with Peers connected but zero share exchange. Decouple advertisement from the verified chain: - advertised_best_share(): peer-facing only (version handshake + timer re-announce). Returns the verified head when present, else the tallest RAW head. Never used for work/share creation, so it cannot cause us to build on an unagreed chain (best_share_hash() still owns that path unchanged). - send_version() now advertises advertised_best_share(). - readvertise_best_share(): re-push the tip walk to all peers bypassing the de-dup set. Fired from run_think() on best-change, and once on a 10s one-shot timer when the verified chain first becomes non-empty, so a peer that handshook during the empty window can still ingest our chain. All advertise paths use the established try_to_lock discipline; the IO thread never blocks on m_tracker_mutex.
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Mirror the LTC timer leg from #104/e01c1606. The event leg (readvertise_best on think work-refresh + clean_tracker best-change) goes dead exactly when think() wedges -- the livelock-adjacent scenario this fix family targets. Arm a one-shot core::Timer(10s) -> readvertise_best() in the run_think IO-phase, fired exactly once when the verified chain first becomes non-empty, so a peer that handshook during the empty window can still ingest our chain even if a later think() cycle wedges. Composes with the merged #97 think-watchdog: timer runs on the IO thread, pure reads, broadcast stays try_to_lock, no new mutex.
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…r leg Mirror the LTC timer leg from #104/e01c1606. The event leg (readvertise_best on think work-refresh + clean_tracker best-change) goes dead exactly when think() wedges -- the livelock-adjacent scenario this fix family targets. Arm a one-shot core::Timer(10s) -> readvertise_best() in the run_think IO-phase, fired exactly once when the verified chain first becomes non-empty, so a peer that handshook during the empty window can still ingest our chain even if a later think() cycle wedges. Composes with the merged #97 think-watchdog: timer runs on the IO thread, pure reads, broadcast stays try_to_lock, no new mutex. Co-authored-by: frstrtr <frstrtr@users.noreply.github.com>
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Root-2: genesis-null head advertisement — COMPLETE fix (supersedes #103)
This is the canonical Root-2 fix (commit e01c160, GPG-signed). It supersedes PR #103 (head
ltc-doge/root2-genesis-null-advert@ b56bfb2), which carried only the on-think / best-change re-advert — a half-fix that regresses whenthink()is wedged. Recommend closing #103 in favour of this PR. LTC only; BTC mirror tracked separately by btc-heap-opt.(a) Bug fixed — genesis-null-advert
On a fresh (
--genesis) LTC node the verified share set is empty at the version handshake.best_share_hash()is verified-only and collapses touint256::ZEROonce peers exist (so work/template never builds on a MAX_TARGET head), so the node advertised ZERO insend_version()→ the peer never issueddownload_shares()→ the chain failed to propagate.Fix:
send_version()now advertises viaadvertised_best_share()(raw head: think's current best, else tallestm_chainhead, else ZERO at true genesis).best_share_hash()stays verified-only for work/template selection — unchanged.(b) Re-advertisement — two legs, think-independent
readvertise_best_share()re-announces on think work-refresh and on best-change (5-deep tip walk, de-dup bypass,try_to_lock, skips rejected shares).m_readvert_timer(core::Timer) is armed lazily once the verified chain first becomes non-empty and firesreadvertise_best_share()on a 10s cadence, plus a one-shot delayed re-advert on first non-empty verified chain. This covers the case the event leg cannot — a peer that connects during a long quiescent gap with no head change, and re-advert progress even ifthink()is wedged.(c) Timer — IMPLEMENTED, not deviated
Unlike #103 (which deviated to think-cycle cadence only), this branch implements the explicit ~10s re-advert timer the spec called for. The timer arms inside the run_think IO-phase and composes with the already-merged PR #97 lock-yield + think-watchdog (ee906e8), which guarantees think progress → arm.
Livelock-safety — confirmed, no new exclusive lock
No new mutex.
advertised_best_share()/readvertise_best_share()are reads; the broadcast path keepstry_to_lock(non-blocking), so nothing on the compute-thread hot path can reintroduce the phase2 livelock signature. +93/-1 node.cpp, +21 node.hpp.