pnl_track_step runs after each matching pass, compares per-block
position-state-now against persisted OpenTradeState (24 B scratch)
and either:
- records entry context (entry_ts_ns, entry_px_x100, entry_size,
realised_at_open) on open transition (prev==0, now!=0); or
- emits a 40-byte TradeRecord into the per-block trade-log buffer
on close transition (prev!=0, now==0), reconstructing implied
exit_px from the realized P&L delta and converting to USD ×100
fixed-point ($50/index-point × 100 = ×5000 multiplier).
Multi-fill averaging (scale-in then partial close) deferred to v2 —
v1 covers the clean open→close case the spec calls out as primary.
LobSimCuda owns three new buffers: open_trade_state_d (n × 24),
trade_log_d (n × TRADE_LOG_CAP × 40), trade_log_head_d (n × u32).
submit_market now takes current_ts_ns and chains pnl_track_step
internally; step_pnl_track() exposed for caller-driven orchestration.
read_trade_records(backtest_idx) drains the per-block ring as
Vec<TradeRecord>; LSP-pinned 40-byte Pod struct from C2 lines up
1:1 with the kernel's hand-rolled byte writes.
pnl_accounting_buy_close fixture: buy 4 lots @ ask top (5500.00),
book moves +5 to bid top 5505.00, sell 4 to close. Expected
realized_pnl = (5505 − 5500.00) × 4 = $20 in price-units, which is
$20 × $50/contract × 100 = 100000 USD ×100 fixed-point. PASS within
$1 fixed-point tolerance.
All 5 Ring 1 fixtures green on RTX 3050.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
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