dash: vardiff hysteresis on power-of-two boundary (F-2)#777
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After F-1 quantizes advertised vardiff to powers of two, the 10% dead-band compares quantized values (ratios only 1/2/0.5) so it is inert. A rig whose un-quantized ideal D sits near a 2^n boundary flaps its advertised bucket 2^n <-> 2^(n+1) on EWMA noise, doubling set_difficulty churn and jittering rig-side hashrate graphs. Apply hysteresis on the UN-QUANTIZED ideal D: hold the current power-of-two bucket [C, 2C) and only re-quantize when D leaves it decisively -- at/above 2C*(1+deadband) (step up) or below C*(1-deadband) (step down). Only widens the transition; round-DOWN cadence, warm-up, min/max clamp and the quantized floor are all preserved. DASH hashrate-vardiff path only; consensus-neutral. Extends test_dash_work_source with hysteresis KATs (up hold+decisive-step, down hold+decisive-step); existing quantize KATs still pass.
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| // (a value we previously advertised). A non-grid seed/hint (e.g. the raw | ||
| // min_difficulty_ or an operator hint) must be corrected onto the grid | ||
| // immediately, not frozen in place by the hysteresis band. | ||
| const bool current_on_grid = (C == std::exp2(std::floor(std::log2(C)))); |
| } | ||
| LOG_INFO << "[Stratum] VARDIFF(hashrate): " << current_difficulty_ << " -> " << d | ||
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| if (d_q == current_difficulty_) return; // decisive move re-adopts same grid step |
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…reward-safe --embedded-mainnet (default OFF) Rebased onto master (#781 io-decouple + #773/#777/#775/#782). Integrates the embedded DASH template arm into the decoupled tip-poll/rpc_pool architecture WHILE preserving both: #781's refresh_executor/resource_template_now split AND every v0.2.4 embedded guard. Default behaviour is UNCHANGED and reward-safe — with --embedded-mainnet OFF (the default) the template stays arm=dashd-fallback, the path the hotel runs, byte-for-byte. Wires the vendored SML/QuorumManager/CCbTx machinery into the live embedded template so the daemonless arm assembles a real DIP-0004 type-5 CCbTx, proven byte-identical to a real dashd getblocktemplate from the raw mnlistdiff wire (merkleRootMNList + merkleRootQuorums recomputed from wire; bestCL; creditPool accrual). The mainnet gate lifts behind the explicit --embedded-mainnet opt-in. Consensus guards (all fail-closed to the reward-safe dashd fallback): - merkleRootQuorums: hash ALL active commitments (no rotated per-index dedup) — byte-identical to dashd (109-quorum from-wire KAT). - H-1: a malformed quorum tail wipes + full-resyncs (never papered over by a later incremental; base-continuity tightened). - DKG mining-phase heights (is_dkg_commitment_window over every enabled llmqType) and superblock heights: refuse embedded. - bestCL freshness: committed ChainLock must be within one block of the tip. - creditPool: INDEPENDENT seed-height gate (the seed cbTx's own nHeight must equal the tip) — catches a seed one block behind that value/hash self-checks miss; pre-emit value re-check + serve-time cache re-validation for the build-vs-serve skew; GBT-xcheck backstop cross-checks the embedded creditPool vs dashd. - C-3: the embedded block excludes all DIP special txs (1-4,6,8,9) — their own-block state effects are not modelled in the committed CbTx (Phase-2). - pre-emit HARD GATE re-validates the built CbTx (both roots + all height-class + bestCL + creditPool checks) before serve; discards to fallback on any failure. Reward-safety posture: --embedded-mainnet is default OFF (unconfigured mainnet nodes are byte-unchanged dashd-fallback). The embedded-ON daemonless seed-lag (arm falls back rather than serving stale at some heights) is deferred as a separate goal; ON is reward-safe (worst case = fallback, never a bad block). Tests (dash embedded suite): node_coin_state 15, coin_state_maintainer 11, stratum_work_source 38, embedded_gbt 10, mnlistdiff_root_parity 4, byte_parity 4, quorum_root 11, mempool 19, node_reception_wire 21, header_chain 8. c2pool-dash builds+links against the #781 io-decoupled main_dash.
frstrtr
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Jul 21, 2026
…reward-safe --embedded-mainnet (default OFF) Rebased onto master (#781 io-decouple + #773/#777/#775/#782). Integrates the embedded DASH template arm into the decoupled tip-poll/rpc_pool architecture WHILE preserving both: #781's refresh_executor/resource_template_now split AND every v0.2.4 embedded guard. Default behaviour is UNCHANGED and reward-safe — with --embedded-mainnet OFF (the default) the template stays arm=dashd-fallback, the path the hotel runs, byte-for-byte. Wires the vendored SML/QuorumManager/CCbTx machinery into the live embedded template so the daemonless arm assembles a real DIP-0004 type-5 CCbTx, proven byte-identical to a real dashd getblocktemplate from the raw mnlistdiff wire (merkleRootMNList + merkleRootQuorums recomputed from wire; bestCL; creditPool accrual). The mainnet gate lifts behind the explicit --embedded-mainnet opt-in. Consensus guards (all fail-closed to the reward-safe dashd fallback): - merkleRootQuorums: hash ALL active commitments (no rotated per-index dedup) — byte-identical to dashd (109-quorum from-wire KAT). - H-1: a malformed quorum tail wipes + full-resyncs (never papered over by a later incremental; base-continuity tightened). - DKG mining-phase heights (is_dkg_commitment_window over every enabled llmqType) and superblock heights: refuse embedded. - bestCL freshness: committed ChainLock must be within one block of the tip. - creditPool: INDEPENDENT seed-height gate (the seed cbTx's own nHeight must equal the tip) — catches a seed one block behind that value/hash self-checks miss; pre-emit value re-check + serve-time cache re-validation for the build-vs-serve skew; GBT-xcheck backstop cross-checks the embedded creditPool vs dashd. - C-3: the embedded block excludes all DIP special txs (1-4,6,8,9) — their own-block state effects are not modelled in the committed CbTx (Phase-2). - pre-emit HARD GATE re-validates the built CbTx (both roots + all height-class + bestCL + creditPool checks) before serve; discards to fallback on any failure. Reward-safety posture: --embedded-mainnet is default OFF (unconfigured mainnet nodes are byte-unchanged dashd-fallback). The embedded-ON daemonless seed-lag (arm falls back rather than serving stale at some heights) is deferred as a separate goal; ON is reward-safe (worst case = fallback, never a bad block). Tests (dash embedded suite): node_coin_state 15, coin_state_maintainer 11, stratum_work_source 38, embedded_gbt 10, mnlistdiff_root_parity 4, byte_parity 4, quorum_root 11, mempool 19, node_reception_wire 21, header_chain 8. c2pool-dash builds+links against the #781 io-decoupled main_dash. CI-fold: build.yml "Build tests" allowlists test_dash_embedded_gbt but not the two byte-parity executables, so CTest registered them (gtest_add_tests AUTO) while CI never built them -> ctest "Not Run" exit 8 (Linux x86_64 red), and the from-wire merkleRoot + real-dashd CbTx round-trip proofs ran in NO CI job. Folded test_dash_embedded_cbtx_byte_parity.cpp + test_dash_mnlistdiff_root_parity.cpp INTO the test_dash_embedded_gbt executable (distinct TEST suites; DASH_FIXTURE_DIR moved to that target) and removed the standalone add_executable/gtest_add_tests registrations. test_dash_embedded_gbt 10 -> 18 cases (byte-parity 4 + from-wire 4), all green; no unbuilt-executable CTest registrations remain.
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F-2 vardiff hysteresis (DASH hashrate-vardiff)
Low-priority polish identified in the #773 review. Cosmetic + consensus-neutral — smooths rig-side hashrate graphs and cuts
set_difficultychurn; no effect on shares, targets, or payout.Problem
After #773 (F-1) quantizes advertised vardiff to powers of two (
d = exp2(floor(log2(d)))), the 10% dead-band (vardiff_deadband_) is inert — it compares already-quantized values, so ratios are only 1, 2, 0.5. A rig whose EWMA-estimated idealDsits near a2^nboundary flaps its advertised difficulty2^n <-> 2^(n+1)on estimator noise (~±24% attau=90s), roughly doublingset_difficultyevents and jittering rig hashrate graphs. No rejects (the P5 gate usesmin(live, issued), both PoT), just churn.Fix
Apply hysteresis on the un-quantized ideal
D. Hold the current power-of-two bucket[C, 2C)and only re-quantize whenDleaves it decisively:D >= 2C * (1 + deadband)D < C * (1 - deadband)[C*(1-deadband), 2C*(1+deadband))keep the current advertisement.Only the current advertisement being on the 2^n grid triggers the hold (a non-grid seed/hint is corrected onto the grid immediately). Preserved: round-DOWN cadence, warm-up, min/max clamp, and the quantized floor (F-1). DASH
use_hashrate_vardiff_path only.Tests
Extends the allowlisted
test_dash_work_source(where theHashrateVardiffQuantizeKATs live) withHashrateVardiffHysteresis:BoundaryNoiseHeldButDecisiveMoveStepsUp— idealDrises past the2^nedge but within the band → bucket held; a decisive move past2C*(1+deadband)→ steps (round-DOWN preserved).LowerMarginHeldButDecisiveDropStepsDown—Ddips below the lower edge but within margin → held; a decisive drop belowC*(1-deadband)→ steps down.Both would FAIL pre-fix (a bare round-DOWN quantize steps the instant
Dcrosses the plain edge). All 9 tests in the binary pass; the 3 existing quantize KATs are unaffected.Consensus-neutrality
git diff origin/master | grep -iE 'get_share_bits|share_bits|share_target|DGW|oracle|payout|pplns'→ empty. Diff touches onlytracker.cpp(vardiff advertisement) and the test.Draft — for merge-tap review, not for merge/deploy.