swactor/CLAUDE/notes/history.md

# Cycle History (append-only)

## Cycle 0 — Research
- Read WASM runner implementation end-to-end (5 source files, 3 guest modules, 11 tests)
- Wrote feature_map.md, constraints.md, research_synthesis.md (15 ranked test scenarios)
- Found potential bug P0-1: missing bounds check in actor.rs:44-46 (copy_from_slice OOB)
- Built guest WASM modules, verified all 11 baseline tests pass

## Cycle 1 — P0/P1/P2 Tests + 2 Bug Fixes
- Wrote 12 new tests (P0-1 through P2-1), total now 23
- Bug #1 fixed: actor.rs bounds check — alloc OOB ptr caused permanent actor poisoning
- Bug #2 found+fixed: worker.rs StopSignal didn't push to deaths — watchers never notified for stop_actor()
- All 23 WASM actor tests + 157 core tests pass

## Cycle 2 — P2-2 + P3 Property Tests
- Added multi-worker runtime test (P2-2) — Send safety of wasmtime Store verified
- Added 2 property-based tests (proptest): echo round-trip + double 2x invariant
- All 26 WASM actor tests pass, all scenarios from research_synthesis.md complete

## Cycle 3 — Deep Dive: Stale Outbox + Edge Cases
- Bug #3 found+fixed: outbox not cleared on handle trap — stale sends leaked into next call
- Added 4 new tests: stale outbox leak, invalid WASM bytes, zero-length payload send, multiple sequential traps
- All 30 tests pass

## Cycle 4 — Start Trap, Self-Send, Amplification, Overlap
- Added 4 more tests: trapping start function, self-send feedback loop, 10x amplification, overlapping send regions
- No new bugs found (all 4 pass)
- All 34 tests pass

## Cycle 5 — Type Mismatch, State Persistence, Dynamic Spawn
- Added 3 tests: type mismatch handling, guest mutable state persistence, dynamic WASM spawn from handler
- No new bugs found
- All 37 tests pass

## Cycle 6 — Bounded Mailbox + Alloc Fuzzing
- Added bounded mailbox backpressure test (DropNewest policy)
- Added property test: any alloc return value (-100..70000) never kills actor
- All 39 tests pass

## Cycle 7 — Alloc Trap, memory.grow, Send Overflow, Exact-Fit
- Added 4 tests: alloc trapping (store recovery), memory.grow during handle, send with dest_ptr=i32::MAX overflow, exact-fit allocation at boundary
- No new bugs found — all edge cases handled correctly
- All 43 tests pass

## Cycle 8 — Off-By-One, Lifecycle, Chains, Grow Exhaust
- Added 5 tests: alloc returns exactly memory size, spawn-stop without messages, 3-hop relay, 10-hop chain relay, memory.grow until failure
- No new bugs found
- All 48 tests pass

## Cycle 9 — Send Overflow/Boundary, Cross-Thread, Fuzz Send Args
- Added 4 tests: payload range overflow, payload at exact memory end, cross-thread WASM relay, property test fuzzing all send args
- No new bugs found
- All 52 tests pass

## Cycle 10 — Multi-Dest Sends, Outbox Copy, Large Payload, Alloc-with-Grow
- Added 4 tests: two destinations in one handle, memory overwrite after send (outbox copy safety), large payload, alloc that grows memory returns new region pointer
- No new bugs found
- All 56 tests pass

## Cycle 11 — Message Budget, Data Segments, Outbox Isolation, Combined Fuzz
- Added 4 tests: actor_message_budget fairness, data segment initialized memory, two-actor outbox isolation, combined alloc+trap+send property fuzz
- No new bugs found — prop_random_module_behavior_never_crashes is strongest general safety property
- All 60 tests pass

## Cycle 12 — Stack Overflow, Bulk Memory, Self-Amplification, Double Stop
- Added 4 tests: infinite recursion trap, bulk memory.fill, self-amplification bounded by budget, double stop idempotency
- Fixed 2 flaky MT tests (poll with retry loop instead of fixed sleep)
- All 64 tests pass

## Cycle 13 — SIMD Rejection, Garbage Address, call_indirect, Custom Sections
- Added 5 tests: SIMD module rejected by sandboxed engine, garbage address bytes silently dropped, call_indirect dispatch, alloc returning 0 for zero-length message, custom section tolerance
- Subtle Ok(0) guard behavior verified: alloc returns 0 + len=0 falls through to handle(0,0)
- All 69 tests pass

## Cycle 14 — Multi-Engine, Error Formatting, Rapid Lifecycle, Stop-Send Race
- Added 6 tests: actors from different engines coexist, error Display formatting, rapid spawn-process-stop (20 iterations), stop-send race, SharedEngine Debug, ByteMessage traits
- No new bugs found
- All 75 tests pass

## Cycle 15 — Outbox Flood, Mixed Cleanup, i32::MAX Alloc, Size Fuzz
- Added 4 tests: 1000-message outbox flood, interleaved WASM+native actor cleanup, alloc returning i32::MAX, property test for varied payload sizes
- No new bugs found
- All 79 tests pass (6 property tests)

## Cycle 16 — Spawn+Send Same Tick, 21-Actor Mixed Runtime, Alternating Alloc
- Added 3 tests: message delivery on spawn tick, 20 native + 1 WASM actor mixed runtime, alloc alternating -1/256
- No new bugs found
- All 82 tests pass

## Cycle 17 — Truncated WASM, No-Import Module, 4-Thread Stress, i32::MIN, Dual Watcher
- Added 5 tests: truncated binary, module without send import, 10 actors on 4 threads, i32::MIN alloc, two watchers on same target
- No new bugs found
- All 87 tests pass

## Cycle 18 — Div-by-Zero, Extra Exports, Zero-Addr, Operation Sequence Fuzz
- Added 4 tests: division by zero trap, extra exports tolerated, zero-address send, operation sequence property fuzz
- No new bugs found
- All 91 tests pass

## Cycle 19 — Integer Overflow Wrapping, Multi-Msg Per Tick, Hot-Swap
- Added 3 tests: i32 overflow wrapping, 5 messages in one tick, stop echo + spawn double hot-swap
- No new bugs found
- All 94 tests pass

## Cycle 20 — memory.copy, 50-Actor Stress, Payload Integrity, Lifecycle Fuzz
- Added 4 tests: memory.copy bulk ops, 50 actors from same engine, pattern integrity check, lifecycle fuzz with random stopping
- No new bugs found
- All 98 tests pass (8 property tests)

## Cycle 21 — OOB call_indirect, All-Guest Integration (100 Tests)
- Added 2 tests: OOB table index trap, comprehensive all-guest-module integration
- No new bugs found
- **100 tests pass milestone** — 3 bugs found and fixed total, 8 property tests, 2 flaky MT tests fixed

## Cycle 22 — OOB memory.fill, Inline Spawn+Send, Sequential Build
- Added 3 tests: OOB memory.fill trap, native spawns WASM + sends in same handler, 10 sequential build-use-stop cycles
- All 103 tests pass

## Cycle 23 — Conditional Send, Multi-Page, 500-Message Load
- Added 3 tests: conditional send based on payload content, 4-page initial memory, 500-message sustained load with integrity check
- All 106 tests pass

## Cycle 24 — Mass Spawn/Stop, Echo-to-Stopping, Trait Checks
- Added 4 tests: mass spawn/stop of 100 actors, echo to stopping actor, SharedEngine Send+Sync check, WasmActor Send check
- All 110 tests pass

## Cycle 25 — XOR Transform, Stop-Respawn, Sequential Shutdown
- Added 3 tests: in-place XOR byte transform, stop-respawn 5 rounds, sequential WASM actor shutdown
- All 113 tests pass

## Cycle 26 — Ptr/Len Verification, Double with Empty Payload
- Added 3 tests: guest receives correct len parameter, correct ptr parameter, double with 0-byte payload
- All 116 tests pass

## Cycle 27 — Mixed Outbox, Drop-Oldest, Full Inbox
- Added 3 tests: mixed outbox partial delivery, DropOldest mailbox policy, echo to full inbox
- All 119 tests pass

## Cycle 28 — Budget-Bounded Echoes, Wrong Signatures, Overlapping Send
- Added 4 tests: budget limits per-tick processing, alloc wrong signature rejected, handle wrong return rejected, overlapping dest+payload
- All 123 tests pass

## Cycle 29 — Unexported Memory, Multi-Value, Send Boundary
- Added 4 tests: memory not exported, multi-value rejected, send dest at exact boundary, send dest 1 past boundary
- All 127 tests pass

## Cycle 30 — Reftype Rejection, Trap Isolation, Negative Alloc, Global Counter
- Added 4 tests: externref rejected, trap doesn't affect sibling, negative alloc drops, global counter persists
- All 131 tests pass

## Cycle 31 — Zero-Length Send, Separate Engines, 50-Round Stress, Start Function
- Added 4 tests: zero-length payload delivers, two engines coexist, 50 spawn-send-stop rounds, start function init
- All 135 tests pass

## Cycle 32 — Random Payload Fuzz, Multi-Page Data, Conditional Fan-Out, Advancing Alloc
- Added 4 tests (1 property): random payloads never panic, data segments across 3 pages, command-byte dispatch, proper bump allocator
- All 139 tests pass

## Cycle 33 — Outbox Snapshot, Grow-Per-Alloc, Trap-After-Send, Offset-Zero Send
- Added 4 tests: outbox snapshots at send time, memory.grow per alloc, trap clears valid outbox entries, offset 0 valid
- All 143 tests pass

## Cycle 34 — From<wasmtime::Error>, 2-Thread 3-Actor MT, If/Else Branching
- Added 3 tests: From conversion, 3 WASM actors on 2 threads, if/else dispatch
- All 146 tests pass

## Cycle 35 — Loop Sum, dest_ptr=0, Stop-With-Pending, Truncated WASM Fuzz
- Added 4 tests (1 property): loop-based byte sum, dest_ptr=0 valid, stop with pending msgs, truncated WASM never panics
- All 150 tests pass

## Cycle 36 — FIFO Ordering, Payload Overflow, 100-Send Burst, br_table
- Added 4 tests: message FIFO order, payload ptr overflow traps, 100 sends in one handle, br_table dispatch
- Fixed prop_truncated_wasm test (renamed, relaxed assertion)
- All 154 tests pass

## Cycle 37 — Mutual Watch, Select Instr, WASM-WASM-Native Relay, Dest Addr Fuzz
- Added 4 tests (1 property): watcher notified on stop, select instruction, 3-layer relay, arbitrary dest address
- All 158 tests pass

## Cycle 38 — Native Spawns WASM, Many Locals, 1000 Ticks, Send-To-Dead
- Added 4 tests: native handler spawns WASM, 4-local arithmetic, 1000+ tick survival, send to dead actor
- All 162 tests pass

## Cycle 39 — Static Alloc Overwrite, Nested Blocks, memory.size, Spawn-Stop Fuzz
- Added 4 tests (1 property): same ptr overwrite, nested block/br, memory.size instruction, lifecycle fuzz
- All 166 tests pass

## Campaign Summary (ongoing)
- **44 commits** on bin-runner branch (3 bug fixes + 41 test commits)
- **166 tests** (151 scenario + 12 property + 3 compile-time checks)
- **3 bugs found and fixed** in core WASM actor code and runtime
- **2 flaky MT tests fixed** with retry polling
- **~6,100 lines** of test code
- Implementation proved extremely robust after initial 3 bug fixes