Phase 0: Deterministic simulation engine #52

Merged

erikinkinen merged 4 commits from 0-deterministic-simulation-engine into main

2026-02-17 07:54:34 +01:00

erikinkinen commented

2026-02-17 07:53:14 +01:00

Owner

Closes #10

Summary

Add Engine::run() to execute workloads with a forked RNG and deterministic history logging.
Centralize ID allocation and event ordering inside the engine for reproducible runs.
Expand engine tests to cover history ordering, error handling, and RNG determinism.

Scope

Included

Engine workload execution and deterministic event logging.
Engine ID allocation helpers and event history tracking.
New/updated tests for run behavior and deterministic RNG usage.

Explicitly excluded

Event replay or IO/log serialization.
Changes to non-engine subsystems or metrics.

Design intent

Keep all simulation mutation and ID allocation inside Engine.
Ensure reproducibility by forking RNGs per workload and logging only successful events in order.
Preserve Phase 0 invariants around explicit events and deterministic runs.

Phase discipline

Phase 0: infrastructure and deterministic execution scaffolding only.
No changes to authority semantics beyond event ordering/logging.

Verification

Tests pass
Model is internally consistent
Documentation updated
No regressions in existing functionality

Notes

history records only successfully applied events; failed events do not advance time or appear in the log.
RNG determinism is validated via a workload that branches on uniform_u32() with a fixed seed.

Closes #10 --- ## Summary - Add `Engine::run()` to execute workloads with a forked RNG and deterministic history logging. - Centralize ID allocation and event ordering inside the engine for reproducible runs. - Expand engine tests to cover history ordering, error handling, and RNG determinism. --- ## Scope ### **Included** - Engine workload execution and deterministic event logging. - Engine ID allocation helpers and event history tracking. - New/updated tests for run behavior and deterministic RNG usage. ### **Explicitly excluded** - Event replay or IO/log serialization. - Changes to non-engine subsystems or metrics. --- ## Design intent - Keep all simulation mutation and ID allocation inside `Engine`. - Ensure reproducibility by forking RNGs per workload and logging only successful events in order. - Preserve Phase 0 invariants around explicit events and deterministic runs. --- ## Phase discipline - Phase 0: infrastructure and deterministic execution scaffolding only. - No changes to authority semantics beyond event ordering/logging. --- ## Verification - [ ] Tests pass - [ ] Model is internally consistent - [ ] Documentation updated - [ ] No regressions in existing functionality --- ## Notes - `history` records only successfully applied events; failed events do not advance time or appear in the log. - RNG determinism is validated via a workload that branches on `uniform_u32()` with a fixed seed.