6 Commits

Author	SHA1	Message	Date
Josh Creek	b43ad207c1	docs(multiplayer): split spec into MULTIPLAYER_SPEC.md, trim task doc to outstanding work ... multiplayer-next.md was a 1662-line mix of standing architecture spec and task-completion tracking, most of which was dense per-task DONE evidence for finished Phases 0-6. Split it: - MULTIPLAYER_SPEC.md (new): the locked architecture decisions, wire format, server-side input handling, prediction/reconciliation, latency/frame-rate budget, and match lifecycle state machine - standing design reference, not task-tracked. - multiplayer-next.md (trimmed 1662 -> ~370 lines): only outstanding work remains - §0 status, §7 Phase 7/8 task tables condensed to "what's left" per task, §8-11 reference material (refactoring notes, gotchas, testing, flagged items). Phases 0-6 collapsed to a pointer at git history instead of ~500 lines of DONE evidence. Also: - Repointed every `multiplayer-next.md §N` code comment (N 1-6) across Game/scripts, Game/tools and Game/tests to MULTIPLAYER_SPEC.md, since those sections moved. Task-number references (`task N.N`, §7-11) correctly still point at multiplayer-next.md. - Updated CLAUDE.md's doc index and docs/TECH_STACK.md's spec-section citations to match. - TODO.md: added a "what's left to actually finish multiplayer (human-actionable)" checklist pulled from multiplayer-next.md §0 and docs/MATCHMAKING.md - things that need a person (hardware, a design decision, a Steam App ID, hands on a controller), not more agent code.	2026-09-04 22:43:13 +01:00
Josh Creek	4fb7ddfecf	docs(multiplayer): consolidate tracking into one document ... multiplayer-todo.md and multiplayer-next.md tracked overlapping information in two places. Fold everything into multiplayer-next.md (architecture decisions, wire format, task breakdown with checkboxes, gotchas list, testing notes) and delete multiplayer-todo.md. Section numbers are unchanged, so existing code comments citing them by section/task number still resolve; update every such reference to point at the new filename.	2026-09-01 12:32:43 +01:00
Josh Creek	75f485667b	feat(multiplayer): Phase 4 prediction correctness + two input-death fixes ... Closes Phase 4's outstanding action-sequence-correctness invariant, then fixes two server-side bugs an adversarial review of that work uncovered. Server simulation, bot observations, collision resources and tick rate are unchanged: the server_physics_parity trace is byte-for-byte identical to HEAD across 360 ticks including both ships' full observation vectors. 4.11 - prediction history filed under the ISSUING sequence _send_local_input filed each post-step predicted state under the timeline's estimate of the sequence the server would consume this tick, trailing issuance by input_lead. The body had integrated the intent issued under _input_seq, so predicted[S] held "state after the intent from now" while the server's authority for S is "state after action(S)". They agree only while the stick is still. Filing under _input_seq costs nothing: which action the ship uses is decided in LocalNetShipController.get_action() and is untouched. Every prior Phase 4 gate held its input steady, and a steady input cannot falsify a sequence label - the 60s runs honestly reported marker=0/3784. New --exercise-input-transitions role toggles thrust every 6 ticks; it is the only gate that can catch a label regression. Verified non-vacuous: the old label fails it at 50%. 4.12 - issued-but-unsimulated sequences, and the release path An attack (delta > 1) issues and sends several sequences for one local physics step. Those gap sequences had no recorded prediction, so a server ack of one reported missing_not_recorded - indistinguishable from ring loss, costing a teleport and resync suppression several times a minute. They are now recorded stateless via record_unsimulated() and answered with a new "skip" decision mode. Free-flight hard snaps: 25/8/4 -> 0/0/0. A release (delta == 0) re-recorded at the unchanged _input_seq, filing the current intent under a sequence that went out carrying a different action; LocalInputTimeline deliberately refuses to mutate an issued sequence, so the ring contradicted the wire. Recording is now skipped on release ticks. 4.13 - two Phase 3 bugs silently killing player input (a) InputJitterBuffer.consume() advanced last_applied_seq on every tick including a starve. Since ingest() discards seq <= last_applied_seq, one starve on a sequence the client had not sent yet stranded the stream one ahead of arrivals permanently - both sides advancing in lockstep, every honest packet discarded on arrival. The client's own input_lead release is enough to trigger it, so input died for ~30 ticks roughly every 6.5s on a clean LAN. Now only gives up on a sequence once strictly newer data proves it lost. Silent-client stall and ring-overflow resync are unchanged. (b) The seq-range guard bounded incoming seq against highest_ingested_seq, which only advances inside ingest(), which that guard gates. After a ~2s host hitch every packet was rejected forever with no diagnostic (600+ consecutive rejections reproduced via SIGSTOP). Third iteration of this guard; each previous version bounded against a value only the accepted path could advance. Adds an escape after 10 consecutive rejections, which grants an attacker nothing the rate limiter does not already bound. (c) The transitions gate reported PASS at 3.76% while input was completely dead, because suppression stops _record_metrics - a worse outage yields fewer samples and a LOWER rate. Now scales the required sample count with run length and asserts the wire's server_stalled bit. Reverting both fixes makes it fail at samples 292/600, server_stalled=true, input_lead=12. Fixing (a) also explained a residual the review had already traced: 151 of 151 action-marker mismatches were the server repeating a stale action on a starve, not a prediction defect. Marker is now 0.00% in all three conditions (was 1.7-2.5%), and free-flight p99 improved to 0.141/0.168/0.154m from 0.170/0.176/0.184m. Two pre-existing test defects fixed alongside: the ball gate asserted RTT-masking on a link with no RTT (flaked 2 in 5; now asserted only at rtt >= 20ms, 5/5 under latency), and the two-bot CI compared scores across a 3-5s window (now polls the scores the server actually held; note score_changed is emitted only on the client path). QA: 72 unit tests; 60s free-flight at LAN/80+-20ms/5% loss; transition gate in all three; 2.0s and 3.5s host-freeze recovery; ball contact x5; two-bot CI x3; all three abuse roles; net/match_net/clock/lobby smokes. Phase 4 sign-off still pending a human playtest at ~100ms RTT - the milestone asks how it feels, which no gate here answers.	2026-08-21 09:17:19 +01:00
Josh Creek	cf73074e27	fix(multiplayer): resolve composition regression from second adversarial review ... A second adversarial review of the previous fix commit found two of its nine fixes silently defeated each other: the seq-range guard (fix for a MEDIUM epoch-mismatch finding) capped the exact variable the ring-overflow resync (fix for the original CRITICAL finding) depends on, making the resync unreachable in production and recreating permanent input death at a lower failure threshold, reachable via ordinary server tick loss alone. - CRITICAL: rebind the seq-range guard to InputJitterBuffer's own highest_ingested_seq (now public) instead of the consumer-side last_applied_seq, so it tracks the client's send epoch rather than a value that can lag arbitrarily far behind during a stall. - HIGH: InputLeadController's release logic still ANDed the old `lead > LEAD_MIN` gate onto the new depth-driven condition, so a backlog the controller never caused still couldn't drain. Split into two independent decisions: the seq-duplicate action follows real depth alone; lead's own bookkeeping separately never drops below its floor. - MEDIUM: widen the CI driver's movement/stalled sampling margin (run_seconds - 2.0, was - 0.5) and assert the peer is still in multiplayer.get_peers() at sample time, since the old margin let the check pass on residual starvation grace after a bot had already disconnected. - LOW: measure horizontal-only displacement in the human smoke test's movement check — the old 3D-distance bar was beatable by pure gravity settling with fully dead input. - LOW: fix a real "clean stderr" violation (match_net.gd broadcasting a departure notice to a peer whose ENet channels are already torn down, including a second peer disconnecting in the same poll batch) by deferring the notification to the next idle frame. - Wire the server's per-slot stalled bit into the client debug overlay for real — a prior commit message claimed this already reached the overlay when only the CI gate actually read it. Re-verified end-to-end against the real production RPC path (not just unit tests in isolation, which is how the composition bug got past the first round): a 2-bot CI match with a 1.5s host SIGSTOP freeze injected mid-run, well past the 0.6s threshold the review reproduced the bug at, now recovers cleanly on repeated runs with zero stderr noise.	2026-08-20 18:26:12 +01:00
Josh Creek	2325313ad2	fix(multiplayer): adversarial review fixes for Phase 3 ... An Opus subagent's adversarial review of Phase 3 found a critical, silent, permanent bug plus eight smaller real issues, all empirically verified with real two- and three-process runs: CRITICAL: InputJitterBuffer's 32-entry ring permanently bricked a player's input once the un-consumed backlog exceeded the ring's capacity - a fresh arrival would land in the exact slot consume() was still waiting on, and since both counters only ever advance, the gap never closed. Reproduced with a real SIGSTOP/SIGCONT host freeze: client movement dropped from ~26m to 0.00m at ~0.7s, worse under real loss (a lossy link lowered the fatal threshold to ~400ms), and reachable via ordinary clock drift with no external trigger at all. Fixed by tracking the highest seq ever ingested and having consume() jump directly to what the ring can still provide once the gap exceeds capacity, instead of starving through an unrecoverable span. Re-verified with a 3s freeze (well past the original threshold): full recovery. HIGH: InputLeadController's release logic was gated on its own past attacks (lead > LEAD_MIN) rather than the real server-reported depth, so a backlog it didn't itself cause was never drained. Fixed to gate on actual depth vs target. MEDIUM-HIGH: the rate limiter's "N consecutive over-budget seconds" streak hard-reset to 0 on any clean window, letting a duty-cycled flood (burst, one clean window, repeat) sustain ~33x budget indefinitely with zero warnings. Replaced with a leaky-bucket accumulator immune to the same evasion by construction. MEDIUM: the seq > server_tick + 20 guard compared two unrelated clock epochs (server process uptime vs. client's own from-zero seq numbering), so it never actually protected anything on a long-running server and could silently drop an honest client's input forever. Bound against the buffer's own last_applied_seq instead. MEDIUM: InputJitterBuffer.stalled was computed but never reached the wire - the one signal that would have made the ring-overflow bug visible anywhere. Now wired through _ship_to_net_body_state. MEDIUM: task 3.6's CI driver's assertions didn't depend on client input reaching the server at all, so it kept passing with the ring-overflow bug actively triggered. Added real ship-movement and non-stalled checks, sampled while bots are still connected (an initial attempt sampled after their own legitimate disconnect, which starves identically to the bug). LOW-MEDIUM: a lead change silently mislabelled _input_history's older entries, since the wire format has no per-entry seq field. Fixed by handling each delta case (ordinary/release/attack) on its own terms. LOW: bandwidth and snapshot-loss overlay metrics froze at their last value during a total outage instead of decaying - exactly when they matter most. Both now report honest post-outage values. LOW: a guard comment on NetworkManager._ping misdescribed the actual disconnect_peer() arguments in use. Corrected. New permanent regression tests: test_ring_overflow_resyncs_to_fresh_data _instead_of_starving_forever, test_release_drains_a_backlog_it_never_ caused_itself, and client-abuse-flood-dutycycle (reproduces the exact duty-cycle evasion). Full regression suite, including the net-sim-latency milestone gate, all abuse roles, and the CI driver, re-run clean after every fix.	2026-08-20 15:28:44 +01:00
Josh Creek	5bbb319161	feat(multiplayer): Phase 3 task 3.3 - client-owned input_lead control loop ... New InputLeadController (scripts/input_lead_controller.gd, standalone and unit-tested like input_jitter_buffer.gd): fast attack (+3 immediately, debounced to once per 30 ticks) on any server-reported starve, slow release (-1 per 60 ticks, gated behind a one-time 2s clean-surplus bar) otherwise, clamped [1, 12]. Deliberately the only thing that adapts buffer depth - the server (InputJitterBuffer) stays a pure reporter, per §3.3's explicit warning that multiple control loops acting on one plant (buffer occupancy) oscillate and present as unattributable sticky controls. Wired into the client's per-tick input send: a lead change is realized as extra distance between the client's outgoing sequence numbers and what the server has consumed - an attack skips extra sequence numbers, a release duplicates the current one (sent again, unincremented). The server's ring buffer needs no special handling for either: a skipped seq is an ordinary drop, a duplicated one is a same-seq resend already discarded by the existing "already consumed" check. Verified with real two-process runs: on a clean LAN, one early attack (a momentary hiccup during connection setup) recovers via two releases within the test's own ~4s window, settling back near minimum. Under sustained 30% simulated loss, lead climbs to 7 via repeated attacks and never releases while genuine loss continues - confirming the debounce, attack, and release gates all fire on real conditions, not just in isolated unit tests. Full regression suite, including the net-sim-latency milestone gate, re-run clean.	2026-08-20 13:14:40 +01:00