jgrusewski 62ab8ed850 feat(sp13): B0 — replay buffer i32 ring + GpuBatchPtrs plumbing
Pure plumbing: threads a new i32 column (aux_sign_labels) through every
layer of the replay path so B1 can wire the aux head's CrossEntropy
classification target without touching any aggregator or batch-shape
contract on its own. No consumer reads the column yet — all labels are
zero-initialized; smoke between B0 and B1 should be bit-identical to
parent 0ad5b6fa4 modulo allocator entropy.

Why split B0 from B1: original Layer B Commit 1 bundled replay plumbing
with the aux head contract change (1->2 dim, MSE->CE, slot 117 retire,
fingerprint bump). Four implementer subagents in a row hit
NEEDS_CONTEXT on brief-accuracy issues — too large for a single
dispatch. Split keeps B0 mechanical and isolates B1 for fresh
implementer with audit-derived brief.

Wiring (data flow):
  1. scatter_insert_i32 kernel mirrors scatter_insert_u32 but preserves
     -1 sentinels (u32 would alias to 4294967295). gather_i32_scalar at
     #18c is symmetric.
  2. ReplayKernels.scatter_insert_i32 field + ld() loader.
  3. GpuReplayBuffer.aux_sign_labels: CudaSlice<i32> ring [capacity] +
     sample_aux_sign_labels: CudaSlice<i32> per-batch gather dst.
  4. insert_batch signature gains aux_sign: &CudaSlice<i32>. Body
     scatter-launches alongside actions/rewards/dones using same
     (ci, cpi, bsi) tuple.
  5. sample_proportional Step 3c launches gather_i32_scalar from ring
     into sample buffer. Both GpuBatchPtrs return paths set
     aux_sign_labels_ptr to sample buffer raw_ptr.
  6. GpuBatchPtrs.aux_sign_labels_ptr: u64 publicly exposed.
  7. GpuExperienceBatch.aux_sign_labels field — collect_experiences_gpu
     alloc_zeros total-sized i32 slice (B1 replaces with producer kernel).
  8. Single production caller training_loop.rs:2032 threads through.

Audit-verified call site cardinality (per implementer 4 finding):
  - 1 production insert_batch caller (training_loop.rs:2032)
  - 1 in-file unit test caller (signature updated)
  - 2 GpuBatchPtrs construction sites (both inside sample_proportional)
  - 1 GpuExperienceBatch construction site (collect_experiences_gpu)

Implementer 4 caught the over-counted 4 sites claim from the original
brief — the 2 extras were doc-comment references to
insert_batch_with_episode_ids (no separate function exists).

Hard rules upheld:
  - feedback_no_partial_refactor: every insert_batch consumer migrates
    atomically (1 prod + 1 test, both updated)
  - feedback_no_stubs: column carries real data through real kernels;
    zero values are valid i32 that B1 overwrites with -1/0/1
  - feedback_isv_for_adaptive_bounds: no new ISV slots; slot 117
    AUX_LABEL_SCALE_EMA retirement deferred to B1 atomic
  - feedback_no_atomicadd: no new producers/reductions
  - feedback_cpu_is_read_only: alloc_zeros + scatter + gather all GPU

Build: cargo check --workspace clean in 21s.

Audit: docs/dqn-wire-up-audit.md SP13 Layer B B0 section added with
wiring diagram, call site cardinality table, and B1 next-steps for
fresh-implementer dispatch.

Files: 92 LOC net across 4 source files + audit doc:
  - crates/ml-dqn/src/replay_buffer_kernels.cu (+21)
  - crates/ml-dqn/src/gpu_replay_buffer.rs (+54)
  - crates/ml/src/cuda_pipeline/gpu_experience_collector.rs (+17)
  - crates/ml/src/trainers/dqn/trainer/training_loop.rs (+1)
  - docs/dqn-wire-up-audit.md (B0 section)

Next: B1 — aux head 1->2 dim, MSE->CE loss, aux_dir_acc reads softmax,
aux_pred_to_isv_tanh logit-diff rewrite, slot 117 retirement,
dqn_param_layout fingerprint bump, kernel populates aux_sign_labels
with real -1/0/1 labels, aux_b1_diag HEALTH_DIAG, 17+ unit tests.
B1 dispatched to fresh implementer with this audit doc as truth-source.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-05 09:43:00 +02:00

Foxhunt

Production HFT trading system in Rust.

Architecture

The workspace contains 32 crates organized as follows:

Core Libraries (16)

Crate Purpose
trading_engine Order processing, FIX 4.4, IB TWS, SIMD, RDTSC timing
risk VaR, Kelly, circuit breakers, kill switches, compliance
risk-data Risk data types and shared structures
trading-data Trading data types
ml DQN Rainbow, PPO, TFT, Mamba2, ensemble inference
ml-data ML data types and feature definitions
data Market data ingestion and storage
backtesting Replay engine, strategy tester
adaptive-strategy Ensemble execution, microstructure analysis
common Shared types, resilience, error handling
storage S3 and local model storage
model_loader Model serialization and loading
market-data Market data feed handlers
database PostgreSQL access layer (SQLx)
config Configuration management
tli CLI commands and tooling

Services (8)

Service Purpose
backtesting_service gRPC backtesting service
broker_gateway_service FIX routing, broker connectivity
trading_service Core trading operations
ml_training_service Model training orchestration
data_acquisition_service Market data acquisition
trading_agent_service Autonomous trading agents
api_gateway gRPC API gateway with auth
web-gateway Axum REST + WebSocket gateway

Frontend

web-dashboard/ -- React 19 + TypeScript + Vite + TradingView charts.

Building

# Check compilation (no PostgreSQL required)
SQLX_OFFLINE=true cargo check --workspace

# Run tests for a specific crate
SQLX_OFFLINE=true cargo test -p <crate> --lib

# Clippy
SQLX_OFFLINE=true cargo clippy --workspace

ML Models

Four production model architectures on Candle v0.9.1 with CUDA:

  • DQN Rainbow -- Deep Q-Network with prioritized replay, dueling heads, noisy nets
  • PPO -- Proximal Policy Optimization with GAE and LSTM policies
  • TFT -- Temporal Fusion Transformer for multi-horizon forecasting
  • Mamba2 -- State space model for sequence prediction

Each model has a standalone trainer and a UnifiedTrainable adapter for the hyperopt pipeline.

Infrastructure

  • Git: Gitea at git.fxhnt.ai (Tailscale-only), Scaleway DEV1-S
  • Observability: OpenTelemetry OTLP (env OTEL_EXPORTER_OTLP_ENDPOINT)
  • Database: PostgreSQL with SQLx offline mode for CI

License

Proprietary. All rights reserved.

Description
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Readme 849 MiB
Languages
Rust 88.2%
Cuda 7.7%
Python 1.3%
Shell 1.1%
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