4 Commits
Author SHA1 Message Date
swaitsandClaude Opus 4.7 2e55484080 chore(release): 0.4.1
Bump workspace version 0.4.0 → 0.4.1.

Patch release: dispatch hot-path performance only. No public API
changes; every chart that compiled against 0.4.0 compiles unchanged
and behaves identically. CHANGELOG.md captures the per-pass writeup
under the 0.4.1 heading.

Headlines (deepest dispatch in the bench suite):
  h8_cross_tree     -82% instructions / -72% cycles  vs pre_lca_fix
  bubble_top        -22% instructions /  -6% cycles  vs handler walk
  terminate_event   -22% instructions / -23% cycles  vs PARENT walk

The runtime LCA helper, is_up_transition, the per-call heapless::Vec
ancestry build, the runtime PARENT bubble walk, and (on timer-free
charts) the entire TimerTable machinery are all gone. Callgrind
reports the entire HSM machinery as a single inlined `step` symbol.

Bench suite expanded from 7 to 13 benches: bubble_leaf/mid/top
quantify handler resolution at varying ancestor depths,
timer_fire_dispatch covers the only path that exercises pop_expired's
non-empty branch, terminate_event covers do_terminate, and
bubble_cross_tree covers the realistic HSM worst case (deep bubble +
deep cross-tree transition).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-04-28 19:11:29 -06:00
swaitsandClaude Opus 4.7 dc97419161 perf: precompute transition/dispatch/terminate paths; shrink TimerEntry to u64
Six codegen-side optimization passes against step() and friends. No
user-facing API changes; all 296 tests pass under no-default, tokio,
embassy, and tokio+journal. Cumulative on h8_cross_tree (deepest
dispatch in the suite): -82% instructions / -72% cycles vs the
pre_lca_fix baseline.

* __PATH_DATA + __PATH_RANGE: per-(from, to) precomputed exit/enter
  sequences. Up/self/lateral semantics fold into one indexed lookup;
  removes lca() and is_up_transition() runtime helpers and the
  per-call heapless::Vec<u16, 16> ancestry build. Hierarchy depth no
  longer bounded by Vec capacity.

* __DISPATCH[(state, event)]: precomputed handler resolution. The
  runtime __PARENT bubble walk + per-hop __handler_lookup call in
  step() collapses to one indexed lookup. Bubble resolution is now
  O(1) regardless of depth -- bubble_top (4-hop) is within 3
  instructions of bubble_leaf (handler on current).
  __handler_lookup retained for timer dispatch.

* __TERMINATE_DATA: per-state precomputed exit chain (root inclusive
  -- chart-root entry/exit actions are valid). do_terminate() indexes
  the slice instead of walking __PARENT, and uses Deque::clear()
  (O(1) in heapless 0.8) instead of pop_front-loop. terminate_event
  bench: -22.5% instr / -23.4% cycles.

* TimerTable empty-skip: pop_expired / min_remaining / decrement /
  cancel_state each get inlined is_empty() early-out with the
  non-empty body marked #[cold].

* Codegen-static timer-machinery elide: when chart has no Duration
  triggers, every TimerTable call is omitted from step() and
  exit_state(). step() returns None directly. dispatch_trigger and
  the timer-fired arms remain but are unreachable; LLVM DCEs them.

* TimerEntry.remaining_ns: u128 -> u64 (~584-year ceiling). Halves
  entry size; replaces u128 saturating-sub with u64. The smaller
  machine struct improves cache density on every bench, even
  timer-free ones.

Bench coverage: four new benches added to cover paths the original
suite missed -- bubble_leaf/mid/top (handler resolution at varying
ancestor depths), timer_fire_dispatch (only bench exercising
pop_expired's non-empty branch and dispatch_trigger), terminate_event
(only bench exercising do_terminate), bubble_cross_tree (deep bubble
+ 10-state cross-tree, the realistic HSM worst case).

See hsmc/benches/baseline.txt for the per-pass delta blocks and
docs/003. latency-analysis.md sections 1, 9, and 12 for the
cost-surface analysis.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-04-28 18:51:21 -06:00
swaitsandClaude Opus 4.7 e633f5dc55 perf: O(H) lca() depth-walk + dispatch bench scoreboard
The runtime `lca()` helper used a `heapless::Vec<u16,32>` ancestry-set
with a linear `contains()` per node — O(H²) and capped at H ≤ 32. The
codegened `__DEPTH` table already had everything needed for an O(H)
depth-walk with no allocation and no hierarchy ceiling. Switch to that.

Also adds an iai-callgrind dispatch bench harness (Linux-only dev-dep)
so future optimizations can be measured deterministically by instruction
count. Seven benches cover: cold start, lateral H=2/4/8, up, self, and a
self-emit chain. Baseline numbers checked in at `hsmc/benches/baseline.txt`.

The latency analysis (`docs/003. latency-analysis.md`) is rounded out
with event-entry-point and cooperative-driving audits — three new
sections documenting the four event injection paths, the run-loop's
cooperative shape, and three correctness invariants (sticky overflow
flag, biased-select trap, cancel-safety on durings).

Bench deltas (cargo bench --bench dispatch -- --baseline=pre_lca_fix):

  h2_cold_start        -1.9%  /  -0.3%   (priming step, no lca() — noise)
  h2_warm_lateral     -22.8%  / -22.1%
  h4_cross_tree       -25.9%  / -10.6%
  h4_up                +1.0%  /  +0.4%   (up-transition, no lca() — noise)
  h4_self             -21.5%  / -11.7%
  h8_cross_tree       -46.2%  / -41.0%   ← headline: deepest LCA stress
  chain_self_emit     -15.4%  / -10.4%

Improvement scales with hierarchy depth, exactly as the O(H²) → O(H)
algorithmic change would predict.

All tests pass under --no-default-features, --features tokio, and
--features embassy.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-04-28 16:58:53 -06:00
swaits 4ea7463089 feat(observe)!: unify journal and trace into single observation pipeline
The codegen now emits one `__chart_observe!` invocation per observable
atom. The macro fans out at compile time to whichever sinks are enabled:
the in-memory journal (`feature = "journal"`), `defmt` (`trace-defmt`),
`log` (`trace-log`), and/or `tracing` (`trace-tracing`). Trace and
journal share the same vocabulary by construction — they cannot
diverge. With no sink feature on, every site expands to `()` (zero
overhead). Multiple trace backends now compose; previously they were
mutually exclusive.

Trace lines use a logfmt-style format with a `[statechart:Name]` prefix
and `key=value` pairs, machine-parseable and greppable. Twenty verbs
cover every observable atom — entries/exits with begin/end pairs,
actions with kind, durings, transitions with the reason that triggered
them, event lifecycle (received/delivered/dropped/queued/failed),
timers, and termination.

BREAKING CHANGES (chart syntax unchanged; observability surface only):

- `TraceEvent::TransitionFired` now carries `reason: TransitionReason`
  showing whether the transition was driven by an event, a timer, or
  internal logic.
- New `TraceEvent` variants for phase pairing: `EnterBegan`, `ExitBegan`,
  `TransitionComplete`, `EventReceived`.
- Trace prefix changed from `[Name]` to `[statechart:Name]`.
- The chart-level `trace;` keyword is parsed for backwards compatibility
  but no longer gates emission.
- `__chart_trace!` / `__chart_journal!` macros removed (doc-hidden).

Verification: 159 integration tests pass, 0 missed mutants, miri 68
tests clean, Creusot 14/14 VCs discharged. Zero overhead confirmed via
`cargo expand` — every observation site expands to `{}` with no sinks
enabled.
2026-04-28 15:24:14 -06:00
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+173
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@@ -4,6 +4,179 @@ All notable changes to this workspace are documented here. The format
follows [Keep a Changelog](https://keepachangelog.com/en/1.1.0/) and
this project adheres to [Semantic Versioning](https://semver.org/).
## 0.4.1 — 2026-04-28
### Performance — dispatch hot path
Six codegen-side optimization passes against `step()` and friends. No
user-facing API changes; all 296 tests pass under `--no-default-features`,
`--features tokio`, `--features embassy`, and `--features tokio,journal`.
Cumulative on `h8_cross_tree` (the deepest dispatch in the bench suite):
**−82% instructions / −72% cycles** vs the pre-`pre_lca_fix` baseline.
See `hsmc/benches/baseline.txt` for per-pass delta blocks and
`docs/003. latency-analysis.md` §1/§9/§12 for the cost-surface analysis.
- **Precomputed transition paths.** For every `(from, to)` state pair,
codegen materializes the exit/enter sequence into a single flat
`__PATH_DATA` blob with a `__PATH_RANGE: [(u16, u16, u16); N²]`
index. `transition()` becomes one indexed range lookup + two slice
loops; the `lca()` runtime helper, `is_up_transition()`, and the
per-call `heapless::Vec<u16, 16>` ancestry build are gone. Up /
self / lateral semantics are baked into the table (empty enter
slice ⇒ up-transition, target excluded; non-empty enter slice
includes the default-descent tail). Hierarchy depth is no longer
bounded by the old 32-state Vec capacity.
- **Precomputed event-dispatch table.** For every `(state, event)`
pair, codegen resolves the handler the runtime `__PARENT` bubble
walk would have found. `__DISPATCH: [(u16, &'static [u16],
Option<u16>); N×E]` stores `(handler_state, action_ids,
transition_target)` per pair; `u16::MAX` in the handler-state slot
is the no-handler sentinel. The runtime walk + per-hop
`__handler_lookup` call in `step()` collapses to one indexed lookup.
Handler resolution is now O(1) regardless of bubble depth — the
`bubble_top` bench (4-hop walk) is now within 3 instructions of
`bubble_leaf` (handler on current state). `__handler_lookup` is
retained for timer dispatch (the `dispatch_trigger` path doesn't
bubble).
- **Precomputed terminate exit path.** Per-state `__TERMINATE_DATA`
table holds the full exit chain up to and including `__Root` (which
may carry root-level `entry:`/`exit:` actions). `do_terminate()`
indexes the table once and iterates the slice, replacing the
runtime `__PARENT` walk + per-iteration match. Queue drain switched
from `while pop_front().is_some()` to `Deque::clear()` (heapless
0.8 implements this as O(1) — resets indices instead of popping
each entry). `terminate_event` bench: −22.5% instr / −23.4% cycles.
- **TimerTable empty-skip.** `pop_expired`, `min_remaining`,
`decrement`, and `cancel_state` each get `#[inline]` + an
`is_empty()` early-out, with the non-empty body split into a
`#[cold]` helper. Runtime branch on charts with timers; the body
stays out-of-line.
- **Codegen-static timer-machinery elide.** When a chart declares no
`Duration` triggers (the common case for event-driven HSMs), every
`TimerTable` call is omitted from `step()` and `exit_state()` at
codegen. `step()` returns `None` directly for the next-tick
deadline. `dispatch_trigger()` and the timer-fired arms remain in
the binary but are unreachable; LLVM DCEs them.
- **`TimerEntry.remaining_ns: u128 → u64`.** Internal-only field type
change. u64 nanoseconds bounds at ~584 years — comfortably past any
realistic `Duration`. Eliminates u128 saturating-sub in
`decrement()` (4–6 instructions per entry → 1–2) and the manual
secs/nanos decomposition in `min_remaining()` (replaced with
`Duration::from_nanos`). The struct shrinks 32 B → 16 B with
alignment, so the entire machine struct gets smaller — every bench's
RAM-hit count drops from tighter cache packing.
### Bench coverage
Four new benches added to cover hot paths the original suite missed:
- **`bubble_leaf` / `bubble_mid` / `bubble_top`** — handler resolution
at varying ancestor depths (0 / 3 / 4 hops) on a single chart.
Quantifies the bubble-walk cost as a function of distance, and
confirms the `__DISPATCH` table makes resolution depth-independent.
- **`timer_fire_dispatch`** — only bench that exercises
`pop_expired`'s non-empty branch and `dispatch_trigger`. The most
expensive single-step bench in the suite (191 instr / 706 cycles).
- **`terminate_event`** — only bench exercising `__check_terminate`'s
true arm and `do_terminate`. 69 instr / 311 cycles.
- **`bubble_cross_tree`** — handler on L1 (4 bubble hops up from
current=L5) targets R5 in a sibling subtree (10-state cross-tree
transition). Realistic HSM worst case; 94 instr / 444 cycles —
almost the same as a plain 7-deep cross-tree because both bubble
resolution and transition path are now O(1) lookups.
## 0.4.0 — 2026-04-28
### Changed — observability (breaking)
- **Unified observation pipeline.** The codegen now emits a single
`__chart_observe!` invocation per observable atom, dispatched at
compile time to whichever sinks are enabled: the in-memory journal
(`feature = "journal"`), `defmt` (`trace-defmt`), `log`
(`trace-log`), and/or `tracing` (`trace-tracing`). All sinks share
the same vocabulary by construction — the journal IS the observation
stream; trace backends are textual renderings of it. With NO sink
feature on, every call site expands to `()` (zero overhead). Multiple
trace sinks may now be enabled simultaneously (previously they were
mutually exclusive).
- **Trace prefix changed.** `[ChartName] verb …` →
`[statechart:ChartName] verb …`. The new form is greppable and
unambiguous in mixed log streams.
- **Trace format is now logfmt-style.** Every line is
`[statechart:Name] <verb> key=value key=value …` (or native structured
fields under `tracing`). Twenty verbs cover every TraceEvent variant
— entries, exits (with begin/end pairs), actions (with kind),
durings, transitions (with **reason** showing what triggered them),
events (received/delivered/dropped/queued/failed), timers, terminate.
- **`trace;` keyword deprecated.** Still parsed for backwards
compatibility, but no longer gates emission. Trace output is now
controlled purely by which `trace-*` cargo feature you enable.
### Changed — journal (breaking)
- **`TraceEvent::TransitionFired` carries `reason: TransitionReason`.**
Replay consumers now see whether a transition was driven by an event
(`Event { event: u16 }`), a timer (`Timer { state, timer }`), or
internal logic (`Internal`).
- **New TraceEvent variants for phase begin/end pairing.**
- `EnterBegan { state }` fires before a state's entry actions /
timers / durings; `Entered` keeps its place as the end marker.
- `ExitBegan { state }` fires before a state's during cancellations
/ timer cancellations / exit actions; `Exited` keeps its place as
the end marker.
- `TransitionComplete { from, to }` fires after a transition's full
exit-then-enter sequence finishes; pairs with `TransitionFired`.
- `EventReceived { event }` fires when an event is popped from the
queue, before handler search; pairs with `EventDelivered` /
`EventDropped` / `TerminateRequested`.
### Added
- **`hsmc/tests/trace_format.rs`** — 11 tests pinning every verb's
exact textual rendering, including a journal/trace atom-count
equivalence test.
- **`TransitionReason`** enum — re-exported from the crate root when
`feature = "journal"` is on. Carried on `TraceEvent::TransitionFired`.
- **Multiple trace backends compose.** Previously enabling more than
one of `trace-defmt` / `trace-log` / `trace-tracing` was a compile
error. Now they fan out independently.
### Migration
Chart syntax is unchanged: every v0.1 / v0.2 / v0.3 statechart compiles
under v0.4 without modification. Breakage is confined to the
observability surface area:
1. **Trace line prefix.** Update grep patterns and log filters from
`[ChartName]` to `[statechart:ChartName]`. The verb after the
prefix is now a single hyphenated token followed by `key=value`
pairs.
2. **`TraceEvent::TransitionFired`** has a new `reason` field. Update
pattern matches:
```rust
// before:
TraceEvent::TransitionFired { from, to } => …
// after:
TraceEvent::TransitionFired { from, to, reason } => …
// or, if you don't care:
TraceEvent::TransitionFired { from, to, .. } => …
```
3. **New `TraceEvent` variants.** If you `match` exhaustively, add
arms for `EnterBegan`, `ExitBegan`, `TransitionComplete`,
`EventReceived`. Otherwise nothing changes.
4. **`trace;` keyword is now a no-op.** Charts that declared it still
compile. Trace output is now controlled purely by which `trace-*`
cargo feature you enable.
5. **`__chart_trace!` and `__chart_journal!` macros are removed.**
These were doc-hidden and not part of the public API; mentioned
here for codebases that grepped through the macro emission for
patches/forks.
## 0.3.0 — 2026-04-27
### Added
Generated
+86 -3
View File
@@ -14,6 +14,15 @@ version = "1.5.0"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "c08606f8c3cbf4ce6ec8e28fb0014a2c086708fe954eaa885384a6165172e7e8"
[[package]]
name = "bincode"
version = "1.3.3"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "b1f45e9417d87227c7a56d22e471c6206462cba514c7590c09aff4cf6d1ddcad"
dependencies = [
"serde",
]
[[package]]
name = "bitflags"
version = "1.3.2"
@@ -195,6 +204,27 @@ dependencies = [
"thiserror",
]
[[package]]
name = "derive_more"
version = "2.1.1"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "d751e9e49156b02b44f9c1815bcb94b984cdcc4396ecc32521c739452808b134"
dependencies = [
"derive_more-impl",
]
[[package]]
name = "derive_more-impl"
version = "2.1.1"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "799a97264921d8623a957f6c3b9011f3b5492f557bbb7a5a19b7fa6d06ba8dcb"
dependencies = [
"proc-macro2",
"quote",
"rustc_version",
"syn",
]
[[package]]
name = "document-features"
version = "0.2.12"
@@ -465,7 +495,7 @@ checksum = "2304e00983f87ffb38b55b444b5e3b60a884b5d30c0fca7d82fe33449bbe55ea"
[[package]]
name = "hsmc"
version = "0.3.0"
version = "0.4.1"
dependencies = [
"crossterm",
"defmt 0.3.100",
@@ -475,6 +505,7 @@ dependencies = [
"futures",
"heapless 0.8.0",
"hsmc-macros",
"iai-callgrind",
"log",
"ratatui",
"tokio",
@@ -484,7 +515,7 @@ dependencies = [
[[package]]
name = "hsmc-macros"
version = "0.3.0"
version = "0.4.1"
dependencies = [
"hsmc",
"proc-macro2",
@@ -495,12 +526,48 @@ dependencies = [
[[package]]
name = "hsmc-verification"
version = "0.3.0"
version = "0.4.1"
dependencies = [
"creusot-std",
"hsmc",
]
[[package]]
name = "iai-callgrind"
version = "0.16.1"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "0b1e4910d3a9137442723dfb772c32dc10674c4181ca078d2fd227cd5dce9db0"
dependencies = [
"bincode",
"derive_more",
"iai-callgrind-macros",
"iai-callgrind-runner",
]
[[package]]
name = "iai-callgrind-macros"
version = "0.6.1"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "4d03775318d3f9f01b39ac6612b01464006dc397a654a89dd57df2fd34fb68c3"
dependencies = [
"derive_more",
"proc-macro-error2",
"proc-macro2",
"quote",
"serde",
"serde_json",
"syn",
]
[[package]]
name = "iai-callgrind-runner"
version = "0.16.1"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "b74c9743c00c3bca4aaffc69c87cae56837796cd362438daf354a3f785788c68"
dependencies = [
"serde",
]
[[package]]
name = "ident_case"
version = "1.0.1"
@@ -773,6 +840,15 @@ dependencies = [
"bitflags 2.11.1",
]
[[package]]
name = "rustc_version"
version = "0.4.1"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "cfcb3a22ef46e85b45de6ee7e79d063319ebb6594faafcf1c225ea92ab6e9b92"
dependencies = [
"semver",
]
[[package]]
name = "rustix"
version = "0.38.44"
@@ -804,6 +880,12 @@ version = "1.2.0"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "94143f37725109f92c262ed2cf5e59bce7498c01bcc1502d7b9afe439a4e9f49"
[[package]]
name = "semver"
version = "1.0.28"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "8a7852d02fc848982e0c167ef163aaff9cd91dc640ba85e263cb1ce46fae51cd"
[[package]]
name = "serde"
version = "1.0.228"
@@ -811,6 +893,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "9a8e94ea7f378bd32cbbd37198a4a91436180c5bb472411e48b5ec2e2124ae9e"
dependencies = [
"serde_core",
"serde_derive",
]
[[package]]
+1 -1
View File
@@ -3,7 +3,7 @@ resolver = "2"
members = ["hsmc", "hsmc-macros", "verification"]
[workspace.package]
version = "0.3.0"
version = "0.4.1"
edition = "2021"
license = "MIT OR Apache-2.0"
authors = ["Stephen Waits <steve@waits.net>"]
+195 -56
View File
@@ -40,14 +40,22 @@ statechart! {
- **`m.run().await` is the whole task body.** Races active durings, the
external event channel, and timer deadlines. The MCU sleeps between
events (embassy's cooperative executor parks all futures).
- **Unified observability.** One observation per atom of execution
fans out at compile time to a journal (`Vec<TraceEvent>`) and/or
textual trace backends (`defmt`, `log`, `tracing`) — they share a
single vocabulary, so they cannot diverge. With no sink feature on,
every site expands to `()` (zero overhead). See
[Observability](#observability--one-journal-multiple-outputs).
- **Deterministic + mechanically verified.** The `journal` feature
records every action, transition, timer, and event in order — same
inputs, byte-identical journal. The runtime queue and timer table
carry Pearlite specs that Creusot + Why3 + alt-ergo + z3 discharge
mechanically (`just verify`). 113 byte-equal expected-vs-actual
journal tests anchor every spec rule.
- **Backward-compatible.** Every v0.1 / v0.2 statechart compiles under
v0.3 unchanged.
mechanically (`just verify`). 159 tests pin every spec rule
(journal sequences + trace-format regression + integration).
- **Backward-compatible chart syntax.** Every v0.1 / v0.2 / v0.3
statechart compiles under v0.4 unchanged. The 0.4 breaks are in
observability surface area only — see
[Migration](#migration-from-v03).
## How a chart behaves — the building blocks
@@ -86,6 +94,7 @@ walk up to the parent and check there. Repeat. If you reach the root
with no handler, the event is silently discarded.
Three corollaries:
- Leaf shadows ancestor for the same trigger.
- Multiple handlers in one state on the same trigger fire in
declaration order; the transition (if any) fires last.
@@ -143,7 +152,7 @@ in.
A timer (`on(after D) => …` or `on(every D) => …`) is **armed** when
its declaring state is entered, **cancelled** when that state is
exited. Descending into a child is *not* an exit, so the parent's
exited. Descending into a child is _not_ an exit, so the parent's
timers keep running while you're in a child. Re-entering a state
restarts its timers from zero.
@@ -174,16 +183,16 @@ overwhelming majority of charts.
The bet is on **simple, consistent semantics**. These features are
omitted on purpose; for each, what to do instead:
| Missing feature | Use instead |
|---|---|
| Missing feature | Use instead |
| ------------------------------- | ----------------------------------------------------------------------------------------------------- |
| Guard conditions on transitions | Split source into two states, or have an action `emit()` a follow-up event for the chart to branch on |
| Orthogonal / parallel regions | Two charts as two tasks connected by channels, or multiple `during:` activities in one state |
| History states | Store last child explicitly in your context; transition to it on re-entry |
| Deferred events | Handle where they arrive (drop/log if not relevant), or have producer check state |
| Internal transitions | `action(Trig) => fn;` (no transition) — exactly that |
| State-local context | All state in the root context; durings borrow disjoint fields |
| Event priorities beyond FIFO | Higher-priority events on a separate channel into a separate, faster machine |
| Runtime statechart modification | Design every variation up front as states |
| Orthogonal / parallel regions | Two charts as two tasks connected by channels, or multiple `during:` activities in one state |
| History states | Store last child explicitly in your context; transition to it on re-entry |
| Deferred events | Handle where they arrive (drop/log if not relevant), or have producer check state |
| Internal transitions | `action(Trig) => fn;` (no transition) — exactly that |
| State-local context | All state in the root context; durings borrow disjoint fields |
| Event priorities beyond FIFO | Higher-priority events on a separate channel into a separate, faster machine |
| Runtime statechart modification | Design every variation up front as states |
## Quickstart
@@ -191,7 +200,7 @@ Add to `Cargo.toml`:
```toml
[dependencies]
hsmc = { version = "0.3", features = ["embassy"] } # or ["tokio"]
hsmc = { version = "0.4", features = ["embassy"] } # or ["tokio"]
```
Minimal timer-only machine:
@@ -327,45 +336,100 @@ into a single during that uses `select` internally.
For `statechart! Foo { ... }` the macro emits:
| Item | What it is |
|---------------------------------|----------------------------------------------------------------------|
| `FooState` | Enum of every user-declared state. |
| `FooActions` | Trait with one async fn per unique action name. User implements. |
| `FooActionContext<'a>` | Wrapper passed to actions. `Deref`s to the root context. `emit()`. |
| `FooCtx<'a>` | Type alias for `FooActionContext<'a>`. |
| `Foo<const QN: usize = 8>` | The machine itself. |
| `FooSender` | Cloneable handle for cross-task / ISR event injection. |
| `Foo::<8>::STATE_CHART` | `&'static str` ASCII tree of the hierarchy (useful for `defmt`/docs).|
| Item | What it is |
| -------------------------- | --------------------------------------------------------------------- |
| `FooState` | Enum of every user-declared state. |
| `FooActions` | Trait with one async fn per unique action name. User implements. |
| `FooActionContext<'a>` | Wrapper passed to actions. `Deref`s to the root context. `emit()`. |
| `FooCtx<'a>` | Type alias for `FooActionContext<'a>`. |
| `Foo<const QN: usize = 8>` | The machine itself. |
| `FooSender` | Cloneable handle for cross-task / ISR event injection. |
| `Foo::<8>::STATE_CHART` | `&'static str` ASCII tree of the hierarchy (useful for `defmt`/docs). |
### Machine methods
| Method | Notes |
|-------------------------------------|------------------------------------------------------------------|
| `new(ctx)` / `new(ctx, channel)` | Construct. Under embassy, pass an `&'static Channel`. |
| `with_queue_capacity::<N>(ctx,...)` | Custom event-queue capacity. |
| `async fn run()` | Drive the machine to completion (async features). |
| `async fn dispatch(ev)` | Push event + drain to quiescence. Same task injection. |
| `fn step(elapsed) -> Option<Duration>` | One unit of work (test/polling driver). |
| `fn send(ev)` | Raw push, non-draining. For tests. |
| `sender() -> Sender` | Clone handle for other tasks / ISRs. |
| `current_state()` | The active leaf state. |
| `is_terminated()` | True after `terminate` event. |
| `has_pending_events()` | Queue non-empty. |
| `context()` / `context_mut()` | Borrow the root context. |
| `into_context(self)` | Consume, return ctx. |
| `STATE_CHART` | Const ASCII diagram. |
| Method | Notes |
| -------------------------------------- | ------------------------------------------------------ |
| `new(ctx)` / `new(ctx, channel)` | Construct. Under embassy, pass an `&'static Channel`. |
| `with_queue_capacity::<N>(ctx,...)` | Custom event-queue capacity. |
| `async fn run()` | Drive the machine to completion (async features). |
| `async fn dispatch(ev)` | Push event + drain to quiescence. Same task injection. |
| `fn step(elapsed) -> Option<Duration>` | One unit of work (test/polling driver). |
| `fn send(ev)` | Raw push, non-draining. For tests. |
| `sender() -> Sender` | Clone handle for other tasks / ISRs. |
| `current_state()` | The active leaf state. |
| `is_terminated()` | True after `terminate` event. |
| `has_pending_events()` | Queue non-empty. |
| `context()` / `context_mut()` | Borrow the root context. |
| `into_context(self)` | Consume, return ctx. |
| `STATE_CHART` | Const ASCII diagram. |
## Feature flags
| Feature | Effect |
|-----------|-------------------------------------------------------------------------|
| (default) | `no_std`, no async runtime. Drive via `step(Duration)` + `send(ev)`. |
| `tokio` | Async actions + `run()`. Targets single-thread via `LocalSet`. |
| `embassy` | Async actions + `run()`. Targets embassy's cooperative executor. `no_std`.|
| Feature | Effect |
| --------- | -------------------------------------------------------------------------- |
| (default) | `no_std`, no async runtime. Drive via `step(Duration)` + `send(ev)`. |
| `tokio` | Async actions + `run()`. Targets single-thread via `LocalSet`. |
| `embassy` | Async actions + `run()`. Targets embassy's cooperative executor. `no_std`. |
`embassy` and `tokio` are mutually exclusive — enabling both is a compile
error.
## Migration from v0.3
The 0.4 breaks are in the observability surface area only; chart
syntax and runtime API are unchanged.
### 1. Trace prefix changed
Trace lines (when `trace-defmt` / `trace-log` / `trace-tracing` is
enabled) now use `[statechart:Name]` instead of `[Name]`. Update any
log filters or grep patterns. The verb after the prefix is now a
single hyphenated token followed by `key=value` pairs (logfmt).
### 2. `TraceEvent::TransitionFired` carries `reason`
Add `reason` to any pattern matches:
```rust
// before:
TraceEvent::TransitionFired { from, to } => …
// after:
TraceEvent::TransitionFired { from, to, reason } => …
// or, if you don't need it:
TraceEvent::TransitionFired { from, to, .. } => …
```
The new field carries `TransitionReason::Event { event }`,
`Timer { state, timer }`, or `Internal` so consumers can see what
triggered the transition.
### 3. New `TraceEvent` variants
If you `match` exhaustively on `TraceEvent`, add arms for the new
variants. Otherwise nothing changes:
- `EnterBegan { state }` — phase begin marker pairs with `Entered`.
- `ExitBegan { state }` — phase begin marker pairs with `Exited`.
- `TransitionComplete { from, to }` — pairs with `TransitionFired`.
- `EventReceived { event }` — fires when an event is popped from the
queue, before handler search.
These are pure observation — no runtime semantic change.
### 4. `trace;` keyword is a no-op
Charts that declared `trace;` continue to compile. The keyword no
longer gates emission — observation is now controlled purely by
which `trace-*` cargo feature you enable. You can leave `trace;` in
or remove it; both work.
### 5. Trace backends are no longer mutually exclusive
Previously, enabling more than one of `trace-defmt` / `trace-log` /
`trace-tracing` was a compile error. Now they fan out independently:
turn on whichever you want.
## Migration from v0.1
v0.1 statecharts continue to compile. New features are purely additive:
@@ -442,12 +506,12 @@ async fn radio_task(lora: LoRaDriver, ch: &'static RadioChan) {
## Examples
| Example | Purpose |
|--------------------|---------------------------------------------------------------------|
| `microwave` | Full-feature pure-event machine: entry/exit, timers, emit, terminate.|
| `microwave_tui` | TUI variant of microwave. |
| `during_radio` | `during:` activities simulating a radio task with RX + TX loops. |
| `embassy_full` | Embassy feature demonstration. |
| Example | Purpose |
| --------------- | --------------------------------------------------------------------- |
| `microwave` | Full-feature pure-event machine: entry/exit, timers, emit, terminate. |
| `microwave_tui` | TUI variant of microwave. |
| `during_radio` | `during:` activities simulating a radio task with RX + TX loops. |
| `embassy_full` | Embassy feature demonstration. |
Run `cargo run --example during_radio --features tokio` to see the
`during:` pattern end-to-end.
@@ -469,12 +533,81 @@ gets to a green proof in one command. See
[`verification/INVARIANTS.md`](verification/INVARIANTS.md) for the
spec-rule → proof mapping.
The `journal` Cargo feature gives you a deterministic execution
trace of every action, transition, timer arm/cancel/fire, queued
emit, event delivery, and termination. Same chart + same events =
byte-identical journal. 113 byte-equal expected-vs-actual journal
tests anchor every spec rule. `cargo mutants` runs cleanly with
0 missed mutants under `--features tokio,journal`.
Beyond Creusot, the suite includes:
- **159 integration tests** — full chart behavior, byte-equal expected-
vs-actual journals for ~113 deterministic-flow tests, plus 11 trace-
format regression tests pinning every observation verb's exact
textual rendering.
- **0 missed mutants** under `cargo mutants --features
tokio,journal,trace-log`.
- **Miri**: 68 tests, no UB.
## Observability — one journal, multiple outputs
Every chart emits a single observation per atom of execution. That
observation fans out to whichever sinks you compile in:
| Feature | Sink |
| --------------- | -------------------------------------------------------- |
| `journal` | In-memory `Vec<TraceEvent>` (replay, byte-deterministic) |
| `trace-defmt` | `defmt::*` log lines |
| `trace-log` | `log::*` log lines |
| `trace-tracing` | `tracing::*` events with structured fields |
With **no** sink feature on, observation is fully elided at compile
time — zero overhead. Multiple sinks can be enabled simultaneously;
the journal IS the observation stream and trace backends are textual
renderings of it, so they cannot diverge.
The textual format is logfmt-style — greppable and regex-parseable:
```
[statechart:Microwave] started chart_hash=0xa1b2c3d4
[statechart:Microwave] entering state=Idle
[statechart:Microwave] action state=Idle action=clear_display kind=entry
[statechart:Microwave] timer-armed state=Idle timer=t0 duration_ns=5000000000
[statechart:Microwave] during-started state=Idle during=poll_sensor
[statechart:Microwave] entered state=Idle
[statechart:Microwave] event-received name=StartButton
[statechart:Microwave] event-delivered name=StartButton handler=Idle
[statechart:Microwave] transition-begin from=Idle to=Heating reason=event:StartButton
[statechart:Microwave] exiting state=Idle
[statechart:Microwave] timer-cancelled state=Idle timer=t0
[statechart:Microwave] during-cancelled state=Idle during=poll_sensor
[statechart:Microwave] action state=Idle action=stop_motor kind=exit
[statechart:Microwave] exited state=Idle
[statechart:Microwave] entering state=Heating
[statechart:Microwave] entered state=Heating
[statechart:Microwave] transition-complete from=Idle to=Heating
```
### The verb vocabulary
Twenty verbs cover every `TraceEvent` variant. Begin/end markers
bracket entry, exit, and transition phases so the actions, timers,
and durings running inside each phase are visible.
| Verb | Fires when |
|---|---|
| `started` | First step of a chart's life — carries `chart_hash` |
| `entering` / `entered` | Begin / end of a state's entry phase |
| `exiting` / `exited` | Begin / end of a state's exit phase |
| `action` | An action fn was called — `kind=entry\|exit\|handler` |
| `during-started` / `during-cancelled` | A `during:` activity started / was dropped |
| `transition-begin` / `transition-complete` | Begin / end of a transition's exit-then-enter sequence |
| `event-received` | An event was popped from the queue |
| `event-delivered` | A handler ran for the event |
| `event-dropped` | The event reached root with no handler |
| `emit-queued` / `emit-failed` | `emit()` from inside an action — queued or rejected |
| `timer-armed` / `timer-cancelled` / `timer-fired` | Timer lifecycle |
| `terminate-requested` | `terminate(...)` event matched, exit chain about to run |
| `terminated` | Chart finished (always last) |
The `reason=` field on `transition-begin` records what triggered the
transition: an event (`event:VariantName`), a timer
(`timer:State/timer-id`), or `internal`. Real-life captures can be
diffed against expected behavior the same way the journal can.
## Status
@@ -484,6 +617,12 @@ tests anchor every spec rule. `cargo mutants` runs cleanly with
- v0.3: `journal` feature + deterministic trace + replay; root
state targetable by chart name; Creusot verification of the
runtime data structures; 113-test deterministic-flow suite.
- v0.4: unified observation pipeline (journal + trace share one
vocabulary, fan out to multiple sinks at compile time); logfmt-
style trace format with `[statechart:Name]` prefix; transition
reasons; entry/exit/transition begin/end markers; multiple trace
backends now compose; chart-level `trace;` keyword deprecated.
Breaking on the `TraceEvent` enum shape; chart syntax unchanged.
- Out of scope (deliberate): guard conditions, orthogonal/parallel
regions, history states, deferred events, internal transitions,
state-local context, event priorities beyond FIFO, runtime
+10
View File
@@ -217,6 +217,16 @@ So a full transition reads top-to-bottom as: cancel durings on the way
out → run exits on the way out → run entries on the way in → start
durings on the way in.
Observers (the journal and any active trace backend) see this as
phase **begin** and **end** markers bracketing the work: an
`EnterBegan { state }` fires before any of that state's entry actions /
timer arms / during starts, and an `Entered { state }` fires after
all of them finish. The same for `ExitBegan` / `Exited`, and
`TransitionFired` / `TransitionComplete` bracket the whole exit-then-
enter sequence of a transition. This is purely a visibility change —
the operational rules above are unchanged — but it lets you tell from
a captured trace which atoms ran inside which phase.
---
## `emit()` — sending events from inside an action
+500
View File
@@ -0,0 +1,500 @@
# 003. Latency analysis: hsmc hot-path cost surface
This is an audit of where wall-clock and code-size cost lives in `hsmc`'s
event-dispatch path. It is intended to inform mitigation work for embedded
and embassy-rs use cases where every microsecond of dispatch overhead
couples directly into hardware-control loop tightness and jitter.
The audit is **analytical**, with three categories of evidence:
1. **Source reading** of `hsmc/src/lib.rs`, `hsmc/src/journal.rs`, and
`hsmc-macros/src/codegen.rs`.
2. **`cargo expand --release`** of two test programs (one with no
observation features, one with `tokio + journal`) to confirm what the
macro really emits.
3. **`cargo rustc --release --emit=asm`** spot-checks of the compiled
output to confirm LLVM-level claims (jump-table lowering, dead-code
elimination of unused name tables, async-closure code size).
The audit deliberately stops short of recommending mitigations. A ranked
menu of candidates is included at the end so a follow-up planning round
can pick from it; nothing here is a commitment.
---
## 1. Cost surface, ranked by per-event impact
| # | Source | Class | Per-event cost (estimate) | Location |
|----|-----------------------------------------------|-----------------------------|------------------------------------------------------------------------------------------------------------|---------------------------------------|
| # | Source | Class | Per-event cost (estimate) | Status |
|----|-----------------------------------------------|-----------------------------|------------------------------------------------------------------------------------------------------------|---------------------------------------|
| 1 | `dispatch().await` loop | Discretionary, async-only | 2 awaits cold-start / 1 await steady-state per dispatched event. ~free if action body never `Pending`-yields. | open |
| 2 | LCA + transition path build | Discretionary | ~~O(H²) `heapless::Vec<u16,32>::contains` scan~~ → ~~O(H) depth-walk~~ → **O(1) `__PATH_RANGE` lookup**. Up/self/lateral folded into the precomputed table; `lca()`, `is_up_transition()`, and the per-call `heapless::Vec<u16,16>` ancestry build are all gone. | resolved |
| 3 | Parent walk for handler search | Discretionary | ~~O(H) `__PARENT` walk + per-hop `__handler_lookup` call~~ → **O(1) `__DISPATCH[(state, event)]` lookup**. Every (state, event) pair statically resolved at codegen. `__handler_lookup` retained for timer dispatch only. | resolved |
| 4 | `__handler_lookup` nested match (timer path) | Intrinsic | Still used for timer dispatch. LLVM lowers to jump tables (verified `LJTI*`). ~1 indirect jump per call. | open (already at floor) |
| 5 | `run_action` dispatch | Intrinsic | One match arm + monomorphized trait call + 1 vtable hop on `&mut dyn QueuePush` (verified devirtualized when callsite type is known). | open (already at floor) |
| 6 | Event queue push/pop | Intrinsic | `heapless::Deque::push_back` / `pop_front`, both O(1). | open (already at floor) |
| 7 | `__chart_observe!` macro arms | Compile-eliminable when off | Zero residue when all sink features off. Each call site collapses to `{};`. | verified zero-cost |
| 8 | Journal `Vec::push` per atom | Conditional on `journal` | Amortized O(1); ~16 B per `TraceEvent`. ~11 push sites fire per transition. | opt-in |
| 9 | Async-fn future size (binary cost) | Discretionary, async-only | ~3000 asm lines of chart machinery for a 5-state chart; dominated by async-fn state machines. | open (mitigation H3) |
| 10 | `tokio::sync::mpsc::unbounded_channel` | Tokio-only, std-bound | Heap-backed channel for cross-task event injection. Embassy uses bounded `embassy_sync::channel`. | feature-specific |
| 11 | TimerTable per-step / per-exit fixed cost | Discretionary | ~~Unconditional `pop_expired` + `cancel_state` calls every step / exit~~ → **inlined `is_empty()` + `#[cold]` non-empty body** (runtime branch on charts that use timers; compile-time elided on timer-free charts). | resolved |
| 12 | TimerEntry size + per-decrement work | Discretionary | ~~`remaining_ns: u128`, 32-byte entry, u128 saturating-sub per decrement~~ → **`u64`, 16-byte entry, u64 saturating-sub** (~584-year ceiling; Duration::from_nanos round-trips exactly). | resolved |
| 13 | `do_terminate()` exit walk | Discretionary | ~~Runtime `__PARENT` walk + `pop_front`-loop queue drain~~ → **precomputed `__TERMINATE_DATA` slice + `Deque::clear()`** (O(1)). | resolved |
Items 2, 3, 11, 12, 13 are fully resolved by the precompute / inline-
empty-check passes in this round of work — see `hsmc/benches/baseline.txt`
for the per-pass delta blocks. Items 4–6 are at or near the algorithmic
floor for hierarchical state machines. Item 7 is verified zero-cost.
Items 1 (async overhead) and 9 (async machinery binary size) are the
only meaningful open items; both are addressable via a `dispatch_sync()`
fast path (mitigation H3 in §9), which would be a user-facing API
change and is therefore out-of-scope for this round.
---
## 2. Per-event cost model (analytical)
For a chart with hierarchy depth `H=3`, one entry action + one exit action,
a simple lateral transition, no observation features, `cargo build
--release`, on a Cortex-M4-class core (~168 MHz):
| Stage | Cycles (rough) | Notes |
|----------------------------------------|--------------------|------------------------------------------------|
| `queue.pop_front` | ~5–10 | `heapless::Deque` index op |
| `__event_to_id` | ~3–5 | match arm (jump table) |
| `__DISPATCH[(state, event)]` lookup | ~5 | one indexed load + sentinel branch |
| `run_action` (1 action) | ~10–20 | match + monomorphized call + 1 vtable hop |
| Path lookup (`__PATH_RANGE`) | ~5 | one indexed load + slice arithmetic |
| Exit chain (H states × A actions) | ~3 × H + 30 × A | per-state work is now ~3 instr each |
| Enter chain (H states × A actions) | ~3 × H + 30 × A | per-state work is now ~3 instr each |
| Timer machinery (timer-free chart) | 0 | codegen-elided when `ir.duration_triggers.is_empty()` |
| Timer machinery (timer chart, no fire) | ~3 | inlined `is_empty()` branches × 3 |
| Timer machinery (timer firing) | ~30–40 | decrement + pop_expired + dispatch_trigger |
| **Total `.step()` steady-state** | ~0.4 – 0.8 µs | for H=3, A=1; user action body excluded |
| Async overhead (`.dispatch()` loop) | per-await checkpoint | ~free if no `Pending`-yield |
These are back-of-envelope numbers; actual measurements would tighten
them by ~2× in either direction, depending on inlining decisions.
For empirical numbers (deterministic, instruction-counted), see
`hsmc/benches/baseline.txt`. Headline numbers (current):
h2_warm_lateral 84 instr / 397 cycles; h4_cross_tree 101 instr / 456
cycles; h8_cross_tree 93 instr / 443 cycles; bubble_top 99 instr /
453 cycles (4-hop handler resolution); bubble_cross_tree 94 instr /
444 cycles (4-hop bubble + 10-state cross-tree); terminate_event 69
instr / 311 cycles; timer_fire_dispatch 191 instr / 706 cycles;
chain_self_emit 419 instr across 4 events (≈105 instr/event).
Cumulative on h8_cross_tree: **-82% instructions / -72% cycles** vs
the original O(H²) LCA scan.
---
## 3. Spot-check evidence
### 3.1 `__chart_observe!` is zero-cost when off (cargo expand)
Test: `tests/state_chart_const.rs`, with no observation features enabled.
In the expanded source (`/tmp/hsmc_expand_no_features.rs`, 911 lines), every
observation site collapses to an empty block:
```rust
// in `step()`:
if self.current.is_none() {
{}; // would be observe_started
self.enter_path(0);
return self.timers.min_remaining();
}
// ...
if let Some((state, trig)) = self.timers.pop_expired(&__DEPTH) {
let __t_state = state;
let __t_trigger = trig;
{}; // would be observe_timer_fired
// ...
}
```
A grep for any of `TraceEvent::`, `::log::`, `::tracing::`, `::defmt::`,
`JournalSink::push` in the expanded code returns **zero matches**. The
macro arms entirely vanish.
`JournalSink` itself becomes a unit struct when the feature is off:
```rust
#[cfg(not(feature = "journal"))]
pub struct JournalSink; // ZST — 0 bytes in the chart struct
```
so the `__journal` field on the chart costs zero bytes at runtime.
### 3.2 Name lookups are dead-code-eliminated (cargo rustc --emit=asm)
Test: `tests/det_lateral.rs`, built with `--features tokio,journal`.
Even with `journal` enabled, a grep across the 22,477 lines of generated
asm for `state_name`, `action_name`, `event_name`, or `timer_name` returns
**zero matches**. The journal stores `u16` indices, not strings, and no
trace-* feature is on, so the name-lookup helper functions are uncalled
and DCE'd from the final binary.
This means even if a user enables `journal` for replay/verification, they
pay zero binary cost for the human-readable name tables until they also
enable a `trace-*` sink.
### 3.3 LLVM lowers handler matches to jump tables
Same asm file. Grep for `LJTI`:
```asm
leaq .LJTI2_0(%rip), %rcx
jmpq *%rax
.LJTI2_0:
.long .LBB2_1-.LJTI2_0
.long .LBB2_28-.LJTI2_0
.long .LBB2_29-.LJTI2_0
.long .LBB2_23-.LJTI2_0
```
Multiple jump tables are present, each sized roughly to the chart's
state/event count. This corroborates the assumption that
`__handler_lookup`'s nested `match (state_id) { match (kind, trigger_id) }`
lowers to a single indirect jump on platforms LLVM can target with one,
not a chain of compares.
### 3.4 Async machinery code size
Symbol-by-symbol asm sizes from `det_lateral`:
| Symbol (async closure / future) | Asm lines | Notes |
|---------------------------------|-----------|----------------------------------------------|
| `Lat::exit_state` | ~275 | one `.await` per exit action |
| `Lat::run_action` | ~349 | match arm + N monomorphized async branches |
| `Lat::run_handlers` | ~826 | loop over actions, each `.await` |
| `Lat::enter_state_no_descent` | ~217 | |
| `Lat::step` | ~970 | inlines `lca`, `is_up_transition`, etc. |
| `Lat::dispatch` | ~137 | thin loop wrapper |
| **Lat-chart total** | **~2,800**| async machinery for one 5-state chart |
For comparison, `Lat::new` is 141 lines. The async coloring
roughly doubles to triples the binary footprint of a chart relative to a
pure sync codegen. On Cortex-M0/M0+ where flash is small, this matters.
### 3.5 Journal expansion adds N pushes, nothing else (cargo expand)
Same test, expanded with `--features tokio,journal`
(`/tmp/hsmc_expand_with_journal.rs`, 2,426 lines vs. 911 lines without).
Counts:
- 104 total `TraceEvent::*` constructions.
- 20 distinct variant names (the full vocabulary).
- 8 `Vec::push` call sites inside `step()` — but only one fires per
invocation (timer-fired path, event-received path, etc., are mutually
exclusive).
The diff against the no-feature expansion is exactly: every `{};`
placeholder becomes a `(&mut self.__journal).push(TraceEvent::...)`. No
other infrastructure is added. No locking, no allocation per push beyond
the amortized `Vec` growth.
---
## 4. Observability cost matrix
Distilled from `lib.rs:158-712` and the spot-checks above:
| Feature(s) | Per-call CPU | Per-call alloc | Off → fully elided? |
|-------------------|-------------------------------------------|--------------------------|-------------------------------|
| `(none)` | 0 | 0 | Yes (verified) |
| `journal` | `Vec::push` ~10 ns amortized | ~16-24 B amortized | n/a |
| `trace-defmt` | format-hash u32 + field write | 0 | Yes |
| `trace-log` | `log_enabled!()` check + format if passes | 0 unless format | Yes (with small residual when on but level filtered) |
| `trace-tracing` | unconditional field collection + span | 0 | Yes (with ~30-cycle residual when on but no subscriber) |
The codegen emits **~11 `__chart_observe!` calls per typical transition**
in deterministic order: `EventReceived` → `EventDelivered` →
`TransitionFired` → `ExitBegan` → `ActionInvoked{Exit}` → `Exited` →
`EnterBegan` → `ActionInvoked{Entry}` → `Entered` → `TransitionComplete`,
plus action-handler markers. That's the multiplier on every per-call
number above.
---
## 5. What is *not* a problem (audited and dismissed)
- **Handler-lookup growth with chart size** — confirmed jump-table
lowering (§3.3). O(1) per event regardless of state or event count
(modulo cache effects from larger jump tables).
- **Trait-object cost on action dispatch** — only the `&mut dyn QueuePush`
proxy is `dyn`. User actions are monomorphized trait methods (one match
arm per action ID, direct calls). One vtable hop per emit, *not* per
action.
- **Observation overhead with features off** — confirmed zero. Verified
three ways: macro arm structure (every body `#[cfg]`-gated), expanded
source (every site is `{};`), and asm (no name-lookup symbols, no trace
symbols).
- **Heap allocation in default build** — `extern crate alloc` is confined
to `journal.rs:26`. With `journal` off, the runtime is fully stack-only.
Verified: no `Vec`, `Box`, or `String` in expanded sync code.
- **`Pin<Box<...>>` futures on the hot path** — none. Chart futures are
inline state machines, not boxed.
- **Tokio `unbounded_channel` for embedded** — irrelevant: tokio is `std`
anyway. Embassy uses bounded `embassy_sync::channel::Channel` (no
alloc).
---
## 6. Event entry points
Events reach the chart's internal `heapless::Deque` via four distinct
paths. Each has its own latency, wakeup, ordering, and backpressure
profile, summarized below.
| Path | API | Backing | Wakeup | Ordering | Backpressure |
|------|-------------------------------------------|--------------------------------------------|-------------------------|----------------------------------------|------------------------------------|
| 1 | `chart.send(event)` (sync, single-task) | `heapless::Deque::push_back` | none — caller drives | FIFO within queue | `Err(QueueFull)` immediate |
| 2a | `chart.sender().send(ev)` (tokio) | `tokio::sync::mpsc::unbounded_channel` | tokio task wake | FIFO; biased select deprioritizes vs. durings | **unbounded memory** |
| 2b | `chart.sender().send(ev)` (embassy) | `embassy_sync::channel::Channel` (bounded) | embassy task wake | FIFO; same biased-select | `Err(Full)` (try_send) or backpressure-await |
| 3 | `actx.emit(ev)` from inside an action | same internal `Deque` as path 1 | none — drained inline | drained synchronously after current handler completes; *before* `step()` returns | sticky overflow flag |
| 4 | return from a `during:` future | `select!` arm in run loop | driver-specific | biased priority over channel events | silent drop on `Deque` full |
**Path 1 (sync send)** — `codegen.rs:2316-2319`. Bare
`Deque::push_back`; owning task only, no synchronization. ~5–10 cycles.
Caller is responsible for invoking `step()` (or `dispatch()` under an
async feature) to actually process the event.
**Path 2 (cross-task `sender()`)** — `codegen.rs:1492` (tokio sender),
`1638` (embassy sender), `1308` / `1405` (run-loop receive sites). The
canonical cross-thread / ISR path per the spec. Tokio uses an unbounded
MPSC (heap-backed; no backpressure signal); embassy uses a bounded
`Channel<M, E, N>` with `try_send` for ISR-safe non-blocking emits and
an `async send` that backpressures the producer. The receiver task
wakes on send; one iteration of the run-loop's `select!` consumes the
event and pushes it into the internal `Deque`.
**Path 3 (self-emit from action)** — `actx.emit(...)` goes through
`EmitProxy::push` (`hsmc/src/lib.rs`) which writes into the same
internal `Deque` as Path 1. Self-emitted events are drained in the
*same* `step()` call that emitted them — `dispatch()` runs `while
!queue.is_empty() { step().await }` until quiescence. Nothing crosses a
task boundary.
**Path 4 (`during:` return)** — `codegen.rs:1306–1313` (tokio with
durings), `1392+` (embassy). Durings are racing futures spawned in the
run-loop's `select!`. When one resolves to an event, the `select!`
unblocks and the event is pushed into the internal `Deque`. The
`select!` is `biased;` so durings have priority over the channel —
relevant if a during is a poll-based driver that's almost always
ready (see §8).
**One ordering caveat**: there is no global FIFO across paths 1–4.
Within each path, events are FIFO; across paths, the order depends on
when each path's wakeup arrives at the run loop. For most charts this
is a non-issue, but a chart that mixes high-frequency cross-task sends
with rapid self-emits could observe self-emits processed before
external events that arrived "first" in wall-clock terms.
---
## 7. Cooperative-driving audit
The library targets embassy-rs's single-priority cooperative scheduler,
where any tight loop without an `.await` can starve other tasks. An
audit of every loop and await pattern in the runtime and codegen:
| Loop / await | Location | Bounded? | Awaits per iter? | Verdict |
|---------------------------------------|---------------------------|-------------------------|--------------------------|---------------------|
| Main `run()` outer | codegen.rs:1290+, 1379+ | by `terminated` flag | yes — always | cooperative |
| `dispatch()` drain loop | codegen.rs:2339 | by queue size | only via `step().await` | suspect — fairness |
| Transition exit/enter slice loops | codegen.rs (transition) | by precomputed slice len| yes (async variant) | OK |
| Termination drain | codegen.rs:2750 | by hierarchy + queue | yes (async variant) | OK |
| Timer decrement / pop | runtime / lib.rs | by timer-table size | sync, off the event-loop | OK |
| Send/recv backends | codegen.rs:1308, 1405 | n/a | always `.await` | cooperative |
No `try_recv` patterns anywhere. No fixed-period polling. The library
is fundamentally event-driven and embassy-friendly.
**One latent fairness characteristic**: the `dispatch()` drain loop —
`while !self.queue.is_empty() { step(Duration::ZERO).await }` — never
yields to the executor between iterations. If user actions are all
synchronous and they emit a chain of follow-on events (action A emits
B, B emits C, …), each `step().await` completes inline, and the loop
becomes effectively synchronous for the duration of the chain. Embassy
high-priority tasks could be delayed by the chain length.
This is **not a bug** — `dispatch()` is documented to drain to
quiescence — but it's worth knowing about. A future option (not part of
this round of work) would be a feature-gated
`embassy_futures::yield_now().await` every Nth iteration, or a
chart-level config to bound chain length. Not done by default because
it would serialize the common case for no benefit.
---
## 8. Correctness invariants surfaced during the audit
Three contracts that aren't bugs, but warrant explicit documentation
because they are easy to miss when reading the code:
**Sticky overflow flag in `EmitProxy`** (`hsmc/src/lib.rs`,
`EmitProxy::push`). When a self-emit fails because the internal `Deque`
is full, an `__overflow` flag is set on the chart. *Every* subsequent
`actx.emit(...)` in the same dispatch chain returns `Err(QueueFull)`,
even after the queue has drained. The flag is cleared at the top of
each `dispatch()` call by `take_overflow()`. This is intentional — it
prevents a chart from observing a partially-applied sequence of
self-emissions where some made it into the queue and others did not.
Authors of actions that emit multiple events should treat
`Err(QueueFull)` as terminal for the current chain.
**Biased select in run loop** (tokio: `codegen.rs:1306–1313`; embassy:
`1392+`). The `select!` is `biased;`, so durings are always polled
before the cross-task channel. For most charts this is the right
priority — a sensor driver should pre-empt a UI event. But for a
`during:` that wraps a poll-based driver (one that returns `Ready`
nearly every poll), the channel can be starved indefinitely. Cure:
make the during yield (`embassy_futures::yield_now`) when there's
nothing real to report.
**Cancel-safety contract on durings** (`hsmc/src/lib.rs:53–60`). Every
`.await` in a `during:` future must be a clean resume point, because
the future will be dropped if the state transitions before it
completes. This is the standard async-cancel-safety contract, but it
is easy to violate by holding a mutable borrow across an await — the
borrow is "valid" when resumed but the surrounding state may have
moved on.
---
## 9. Candidate mitigations (menu, NOT a commitment)
Sized for sequencing in a follow-up plan-mode session. "Effort" is gut
feel: L = afternoon, M = couple of days, H = a week or more.
| ID | Mitigation | Targets | Impact | Effort | Cost |
|-----|-----------------------------------------------------------------------------------------------------------------------------------|-----------|-----------------------------------------|--------|---------------------------------------|
| H0 | Replace `lca()` with an O(H) depth-walk via the `__DEPTH` table. | #2 | **Landed.** | - | - |
| H1 | Codegen per-(from, to) precomputed exit/enter chains as `__PATH_DATA` + `__PATH_RANGE`. | #2 | **Landed.** Up/self/lateral folded into one indexed lookup; `lca()` and `is_up_transition()` removed. | - | ~`6·N²` B index + ~`N²·H` B path data |
| T1 | Inlined `is_empty()` early-out on `pop_expired` / `min_remaining` / `decrement` / `cancel_state` with `#[cold]` non-empty bodies. | #11 | **Landed.** | - | - |
| T2 | Codegen-static elide of all `TimerTable` calls when `ir.duration_triggers.is_empty()`. | #11 | **Landed.** Most charts are timer-free; `step()` returns `None` directly. | - | - |
| H4 | `__DISPATCH[(state, event)]` const array; one indexed lookup replaces the runtime __PARENT bubble walk + per-hop `__handler_lookup`. | #3 | **Landed.** Each (state, event) statically resolved at codegen. | - | ~24 B per (state, event) pair |
| U1 | Shrink `TimerEntry.remaining_ns: u128 → u64` (~584-year ceiling). Halves entry size; replaces u128 saturating-sub with u64. | #12 | **Landed.** | - | - |
| K1 | `__TERMINATE_DATA` per-state precomputed exit chain (root inclusive); `do_terminate()` indexes a slice instead of walking __PARENT, and uses `Deque::clear()` (O(1)) for the queue drain. | #13 | **Landed.** terminate_event -22.5% instr / -23.4% cycles. | - | ~`(H+1)·N` B path data |
| H3 | Provide a `dispatch_sync()` API that bypasses `.await` when the chart's actions are fully synchronous. | #1, #9 | High for sync-action charts | L-M | API surface growth (user-facing) |
| H5 | Sparse `__PATH_RANGE` / `__DISPATCH` for very large charts (N > 64): emit only reachable pairs with a small perfect-hash. Latency-neutral; cuts O(N²) static memory growth. | cost mitigation | Low at typical N; significant at N > 100 | M | codegen complexity |
| M1 | Eliminate the trailing `step().await` in `dispatch()` when queue empties mid-step. | #1 | Low | L | minor refactor |
| M2 | Lazy field eval in `trace-tracing` arm using `tracing`'s field-closure form to skip evaluation when filtered. | #8 (on) | Low | L | none |
H0/H1/T1/T2/H4/U1/K1 all landed in the most recent round of work.
Callgrind now reports the entire HSM machinery as a single `step`
symbol — every helper inlined. The only remaining optimization avenue
that meaningfully affects per-event latency is H3 (`dispatch_sync()`),
which is excluded as user-facing. Memory-side mitigations (H5) only
matter for N > 64-state charts; embedded users with large charts are
the audience.
---
## 10. Where to look in the source
For anyone reading this audit and wanting to verify or extend it:
- **`hsmc/src/lib.rs`**
- `:94` — the `#![cfg_attr(... no_std)]` boundary
- `:158-712` — `__chart_observe!` macro, all observation arms
- `:737-772` — `JournalSink` ZST/Vec duality
- **`hsmc/src/journal.rs`**
- `:26-32` — `extern crate alloc` and `Vec` import (only here)
- `:65-150+` — `TraceEvent` enum (the journal vocabulary)
- **`hsmc-macros/src/codegen.rs`**
- `compute_transition_paths()` (top of file, after `compute_chart_hash`) — builds `__PATH_DATA` + `__PATH_RANGE` at codegen time
- `__PARENT`, `__DEPTH`, `__DEFAULT_CHILD`, `__PATH_DATA`, `__PATH_RANGE` static-table emission (search "const __PARENT")
- `step()` (search "fn step" / "async fn step") — sync vs. async branches
- `dispatch()` await loop (search "fn dispatch")
- `run_action` (search "fn run_action") — sync vs. async
- `transition` (search "fn transition") — now a thin slice-iter wrapper
- name-lookup helpers (`__state_name`, `__action_name`, etc.) at `:631-667`
- **Test reference shape**: `hsmc/tests/state_chart_const.rs` is the
smallest sync-only chart in the tree; `hsmc/tests/det_lateral.rs` is
the reference async + journal shape used for the asm spot-check.
---
## 11. Reproducing the spot-checks
```sh
# Zero-cost observation verification (expand → no observation residue)
cargo expand --release --test state_chart_const \
> /tmp/expand_no_features.rs --manifest-path hsmc/Cargo.toml
grep -E "TraceEvent::|::log::|::tracing::|::defmt::" /tmp/expand_no_features.rs
# expect: no matches
# Journal expansion (count of TraceEvent push sites)
cargo expand --release --test det_lateral --features tokio,journal \
--manifest-path hsmc/Cargo.toml \
| grep -c "TraceEvent::"
# expect: ~100
# Asm spot-check (jump tables, function sizes, name DCE)
cargo rustc --release --test det_lateral --features tokio,journal \
--manifest-path hsmc/Cargo.toml -- --emit=asm
ASM=$(find target -name 'det_lateral*.s' | head -1)
grep -E "LJTI|jmpq?[[:space:]]+\*" "$ASM" # jump tables
grep -E "state_name|action_name" "$ASM" # expect no matches
```
---
## 12. Summary
`hsmc`'s hot path is mostly already at the algorithmic floor for
hierarchical state machines. The intrinsic per-event cost (parent walk,
handler lookup, action dispatch, queue ops) is small and well-monomorphized.
Observation cost is verified zero when features are off, and stays
proportional to the user's chosen sink mix when on.
**Items #2, #3, #11, #12, and #13 in §1 have all landed** across six
optimization passes (H0 → H1 → T1 → H4 → T2 → K1+U1). Cumulative impact
on the deepest dispatch (h8_cross_tree) is **-82% instructions / -72%
cycles** vs the original O(H²) LCA scan. The headline wins by bench:
- `terminate_event` 69 instr / 311 cycles (~14 instr of HSM work after
subtracting bench wrapper) — `do_terminate()` is one indexed slice
+ `Deque::clear()`.
- `bubble_top` 99 instr / 453 cycles — 4-hop handler resolution
collapses to one indexed `__DISPATCH` lookup; per-dispatch cost is
bench-shape-independent.
- `bubble_cross_tree` 94 instr / 444 cycles — realistic HSM worst
case (deep bubble + 10-state cross-tree) costs the same as a plain
cross-tree because bubble lookup is O(1) and transition is
O(path-length).
- `h8_cross_tree` 93 instr / 443 cycles — 7-deep cross-tree dispatch.
Callgrind reports the entire HSM machinery as a single `step` symbol —
`run_handlers`, `run_action`, `transition`, `do_terminate`,
`exit_state`, `enter_state_no_descent`, `EmitProxy::push`, all four
`TimerTable` methods, the dispatch-table lookup, and the
terminate-path lookup are all inlined.
Cost remaining, in priority order:
1. **Async coloring code-size cost** (item #9) — chart machinery is
~3,000 asm lines for a 5-state chart, dominated by async-fn state
machines. Mitigation H3 (a `dispatch_sync()` fast path) would let
users with all-sync actions skip this entirely. **User-facing API
change** — out of scope for the current optimization pass.
2. **Bench-wrapper noise floor** — at the smallest dispatch's ~38–80
instructions, the iai-callgrind wrapper (`black_box`, `send`,
instrumented call-edge crossing) accounts for ~45 instructions.
Sub-bench-wrapper improvements are below the measurement floor.
3. **Memory cost of `__PATH_DATA` / `__PATH_RANGE` / `__DISPATCH` /
`__TERMINATE_DATA` at large N** — `__PATH_RANGE` is O(N²);
`__DISPATCH` is O(N×E); `__TERMINATE_DATA` is O(N×H). For N ≤ 32 /
E ≤ 16 / H ≤ 8 the total static footprint is a few KiB. A
64-state × 32-event chart would push past ~80 KiB. Mitigation H5
sketches a sparse encoding.
All addressable purely in `hsmc-macros/src/codegen.rs` and `hsmc/src/lib.rs`
without breaking runtime semantics or feature gates. The bench harness
in `hsmc/benches/dispatch.rs` (13 benches, every dispatch shape
covered) is in place to measure each mitigation as it lands.
+971 -360
View File
File diff suppressed because it is too large. Load diff
+6 -4
View File
@@ -26,10 +26,12 @@ pub struct Ir {
/// Duration triggers referenced anywhere, in first-seen order.
/// Each one gets a trigger id used by the timer table.
pub duration_triggers: Vec<DurationTrigger>,
/// True when the chart declared `trace;` at root. Codegen routes
/// trace calls to `::hsmc::__chart_trace!`, which dispatches to a
/// backend (defmt / log / tracing / no-op) based on the user's
/// `hsmc/trace-*` feature selection in their `Cargo.toml`.
/// Set when the chart declared `trace;` at root. Retained for
/// backwards-compatible parsing — the keyword no longer gates
/// observation emission. As of 0.4 every chart unconditionally
/// emits `__chart_observe!` calls, and the actual trace fan-out is
/// chosen by the user's `hsmc/trace-*` cargo feature selection.
#[allow(dead_code)]
pub trace_enabled: bool,
}
@@ -1,3 +1,5 @@
#![allow(unexpected_cfgs)]
use hsmc::statechart;
#[derive(Debug, Clone)]
@@ -1,68 +1,13 @@
warning: unexpected `cfg` condition value: `tokio`
--> tests/ui/t9_8_unknown_target.rs:8:1
|
8 | / statechart! {
9 | | M {
10 | | context: Ctx;
11 | | events: Ev;
... |
17 | | }
| |_^
|
= note: no expected values for `feature`
= note: using a cfg inside a macro will use the cfgs from the destination crate and not the ones from the defining crate
= help: try referring to `statechart` crate for guidance on how handle this unexpected cfg
= help: the macro `statechart` may come from an old version of the `hsmc_macros` crate, try updating your dependency with `cargo update -p hsmc_macros`
= note: see <https://doc.rust-lang.org/nightly/rustc/check-cfg/cargo-specifics.html> for more information about checking conditional configuration
= note: `#[warn(unexpected_cfgs)]` on by default
= note: this warning originates in the macro `statechart` (in Nightly builds, run with -Z macro-backtrace for more info)
warning: unexpected `cfg` condition value: `embassy`
--> tests/ui/t9_8_unknown_target.rs:8:1
|
8 | / statechart! {
9 | | M {
10 | | context: Ctx;
11 | | events: Ev;
... |
17 | | }
| |_^
|
= note: no expected values for `feature`
= note: using a cfg inside a macro will use the cfgs from the destination crate and not the ones from the defining crate
= help: try referring to `statechart` crate for guidance on how handle this unexpected cfg
= help: the macro `statechart` may come from an old version of the `hsmc_macros` crate, try updating your dependency with `cargo update -p hsmc_macros`
= note: see <https://doc.rust-lang.org/nightly/rustc/check-cfg/cargo-specifics.html> for more information about checking conditional configuration
= note: this warning originates in the macro `statechart` (in Nightly builds, run with -Z macro-backtrace for more info)
warning: unexpected `cfg` condition value: `journal`
--> tests/ui/t9_8_unknown_target.rs:8:1
|
8 | / statechart! {
9 | | M {
10 | | context: Ctx;
11 | | events: Ev;
... |
17 | | }
| |_^
|
= note: no expected values for `feature`
= note: using a cfg inside a macro will use the cfgs from the destination crate and not the ones from the defining crate
= help: try referring to `statechart` crate for guidance on how handle this unexpected cfg
= help: the macro `statechart` may come from an old version of the `hsmc_macros` crate, try updating your dependency with `cargo update -p hsmc_macros`
= note: see <https://doc.rust-lang.org/nightly/rustc/check-cfg/cargo-specifics.html> for more information about checking conditional configuration
= note: this warning originates in the macro `statechart` (in Nightly builds, run with -Z macro-backtrace for more info)
error[E0046]: not all trait items implemented, missing: `NonExistent`
--> tests/ui/t9_8_unknown_target.rs:19:1
--> tests/ui/t9_8_unknown_target.rs:21:1
|
8 | / statechart! {
9 | | M {
10 | | context: Ctx;
11 | | events: Ev;
10 | / statechart! {
11 | | M {
12 | | context: Ctx;
13 | | events: Ev;
... |
17 | | }
19 | | }
| |_- `NonExistent` from trait
18 |
19 | impl MActions for MActionContext<'_> {}
20 |
21 | impl MActions for MActionContext<'_> {}
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ missing `NonExistent` in implementation
+23 -11
View File
@@ -17,25 +17,30 @@ exclude = ["examples/microwave_tui.rs"]
default = []
tokio = ["dep:tokio"]
embassy = ["dep:embassy-sync", "dep:embassy-time", "dep:embassy-futures"]
# Auto-tracing backends — pick at most one. When the user opts a chart
# into `trace;`, the macro emits calls to an internal dispatcher that
# routes to whichever backend is enabled here. With NO backend feature
# enabled, `trace;` is a no-op (zero overhead). Enabling more than one
# backend produces a duplicate-macro compile error — that's intentional.
# Auto-tracing sinks — every chart emits `__chart_observe!` calls
# unconditionally; whichever of these sinks you enable is what gets
# textual log lines. Pick zero, one, or any combination — the
# observation pipeline fans out to all enabled sinks and the in-memory
# journal (below). With NO sink feature enabled, observation is fully
# elided at compile time (zero overhead).
#
# Format: `[statechart:<Name>] <verb> key=value …` (logfmt-style,
# greppable, regex-parseable). The `tracing` backend uses native
# structured fields instead of stringly key=value pairs.
trace-defmt = ["dep:defmt"]
trace-log = ["dep:log"]
trace-tracing = ["dep:tracing"]
# Journaling backend. When enabled, the macro emits calls into an
# in-memory journal recording every observable atom: entries, exits,
# action invocations, during start/cancel, timer arm/cancel/fire, emits,
# event delivery, transitions, and termination. Used to make charts
# replay-deterministic and to catch semantic regressions in CI.
# In-memory journal sink. When enabled, every `__chart_observe!` site
# also records a `TraceEvent` into the per-machine `JournalSink`. The
# journal is the authoritative byte-deterministic atom-by-atom record
# of chart execution; trace backends are textual renderings of the
# same vocabulary.
# Requires `alloc` (the journal grows dynamically). Off by default —
# zero overhead and no `alloc` requirement when not enabled.
journal = []
[dependencies]
hsmc-macros = { path = "../hsmc-macros", version = "0.3.0" }
hsmc-macros = { path = "../hsmc-macros", version = "0.4.1" }
heapless = "0.8"
tokio = { version = "1", features = ["sync", "time", "rt", "macros"], optional = true }
embassy-sync = { version = "0.8", optional = true }
@@ -52,6 +57,9 @@ ratatui = "0.28"
crossterm = { version = "0.28", features = ["event-stream"] }
futures = "0.3"
[target.'cfg(target_os = "linux")'.dev-dependencies]
iai-callgrind = "0.16"
[[example]]
name = "microwave"
required-features = ["tokio"]
@@ -64,3 +72,7 @@ required-features = ["tokio"]
name = "embassy_full"
required-features = ["embassy"]
crate-type = ["lib"]
[[bench]]
name = "dispatch"
harness = false
+176
View File
@@ -0,0 +1,176 @@
# hsmc dispatch baseline — instruction counts from iai-callgrind.
#
# Current numbers reflect the codebase after the terminate-path + u64-ns
# pass. `do_terminate()` indexes into a precomputed `__TERMINATE_DATA`
# table (one slice per starting state, root inclusive); `TimerEntry`'s
# `remaining_ns` field shrunk from u128 to u64 (~584 years of headroom),
# halving the entry size and replacing per-step u128 saturating-sub work
# with u64. The smaller machine struct improves cache density on every
# bench, even those that don't use timers.
#
# Re-run with:
#
# cargo bench --bench dispatch
#
# Named baselines under target/iai/ for diffing past changes:
# pre_lca_fix — original O(H²) LCA contains() scan
# before_path_precompute — post-LCA-fix, pre-precompute
# before_timer_skip — post-precompute, pre-timer-skip (runtime is_empty)
# before_dispatch_precompute — post-timer-skip, pre-dispatch-table
# before_timer_elide — post-dispatch-table, pre-codegen-elide
# before_terminate_and_timer_opts — post-codegen-elide, pre-terminate-path / u64
#
# To diff a future change against the current numbers:
#
# cargo bench --bench dispatch -- --save-baseline=before_<your_change>
# <change>
# cargo bench --bench dispatch -- --baseline=before_<your_change>
#
# Numbers below are from a 6.19.14-zen kernel x86_64 box, valgrind 3.25.1,
# iai-callgrind 0.16.1, --release.
dispatch::dispatch::h2_cold_start cold:setup_h2_cold()
Instructions: 38
Estimated Cycles: 201
dispatch::dispatch::h2_warm_lateral warm:setup_h2_warm()
Instructions: 84
Estimated Cycles: 397
dispatch::dispatch::h4_cross_tree cross:setup_h4_warm()
Instructions: 101
Estimated Cycles: 456
dispatch::dispatch::h4_up up:setup_h4_warm()
Instructions: 98
Estimated Cycles: 384
dispatch::dispatch::h4_self self_:setup_h4_warm()
Instructions: 101
Estimated Cycles: 456
dispatch::dispatch::h8_cross_tree cross:setup_h8_warm()
Instructions: 93
Estimated Cycles: 443
dispatch::dispatch::bubble_leaf leaf:setup_bubble_warm()
Instructions: 99
Estimated Cycles: 453
dispatch::dispatch::bubble_mid mid:setup_bubble_warm()
Instructions: 99
Estimated Cycles: 453
dispatch::dispatch::bubble_top top:setup_bubble_warm()
Instructions: 99
Estimated Cycles: 453
dispatch::dispatch::timer_fire_dispatch fire:setup_timer_fire_armed()
Instructions: 191
Estimated Cycles: 706
dispatch::dispatch::terminate_event quit:setup_term_warm()
Instructions: 69
Estimated Cycles: 311
dispatch::dispatch::bubble_cross_tree switch:setup_bubble_cross_warm()
Instructions: 94
Estimated Cycles: 444
dispatch::dispatch::chain_self_emit chain:setup_chain_warm()
Instructions: 419
Estimated Cycles: 1301
# ─── LCA O(H) fix delta (pre_lca_fix → before_path_precompute) ──────
#
# Bench Instr Δ Cycle Δ
# h2_warm_lateral -22.8% -22.1%
# h4_cross_tree -25.9% -10.6%
# h4_self -21.5% -11.7%
# h8_cross_tree -46.2% -41.0% ← deepest LCA stress
# chain_self_emit -15.4% -10.4%
#
# ─── Precompute-paths delta (before_path_precompute → before_timer_skip) ──
#
# Bench Instr Δ Cycle Δ
# h2_warm_lateral -19.5% -4.8%
# h4_cross_tree -45.0% -28.6%
# h8_cross_tree -48.6% -34.8%
# chain_self_emit -28.1% -14.6%
#
# ─── Timer empty-skip delta (before_timer_skip → before_dispatch_precompute) ──
#
# Bench Instr Δ Cycle Δ
# h2_warm_lateral -30.8% -35.1%
# h4_cross_tree -38.4% -35.4%
# h8_cross_tree -54.4% -52.9%
# chain_self_emit -27.9% -29.2%
#
# ─── Dispatch-table delta (before_dispatch_precompute → before_timer_elide) ──
#
# Bench Instr Δ Cycle Δ
# bubble_mid -19.4% -4.7% 3-hop __PARENT walk → table lookup
# bubble_top -22.3% -5.8% 4-hop walk → table lookup
# h8_cross_tree +4.2% +15.8% cold-cache miss on __DISPATCH (warm-cache neutral)
#
# ─── Timer-elide delta (before_timer_elide → before_terminate_and_timer_opts) ──
#
# Bench Instr Δ Cycle Δ
# h2_warm_lateral -26.9% -9.7%
# h4_cross_tree -22.2% -20.1%
# h8_cross_tree -24.2% -20.8%
# bubble_top -22.1% -23.2%
# chain_self_emit -18.0% -8.4%
#
# ─── Terminate-path + u64-ns delta (before_terminate_and_timer_opts → current) ──
#
# Bench Instr Δ Cycle Δ Notes
# h2_cold_start -2.6% -14.1% smaller machine struct, tighter cache
# h2_warm_lateral -3.4% -21.2% (RAM hits 11→8)
# h4_cross_tree -3.8% -1.7%
# h4_up -3.9% -22.3% (RAM hits 10→7)
# h4_self -3.8% -8.4%
# h8_cross_tree -1.1% -0.7%
# bubble_leaf -6.6% -9.6%
# bubble_mid -6.6% -3.0%
# bubble_top -6.6% -9.6%
# timer_fire_dispatch +2.7% -12.6% smaller TimerEntry → -3 RAM hits
# terminate_event -22.5% -23.4% ← headline: precomputed exit path + queue.clear()
# bubble_cross_tree -2.1% -0.9%
# chain_self_emit -0.9% -3.1%
#
# Two changes in this pass:
#
# (1) `__TERMINATE_DATA` / `__TERMINATE_RANGE` — per-state precomputed
# exit chain up to and including __Root. `do_terminate()` indexes the
# table once and iterates the slice, replacing the runtime `__PARENT`
# walk + per-iteration match. Also swapped the queue-drain loop
# (`while self.queue.pop_front().is_some() {}`) for `self.queue.clear()`,
# which heapless 0.8 implements as O(1) (resets indices, no per-element
# pop). Together: -22% instr / -23% cycles on terminate_event, the
# headline win the user asked for.
#
# (2) `TimerEntry.remaining_ns: u128 → u64`. Internal-only field type
# change. u64 nanoseconds bounds at ~584 years — past any realistic
# Duration. Eliminates u128 saturating-sub in `decrement()` (4-6 instr
# → 1-2 instr per entry per step) and the manual secs/nanos
# decomposition in `min_remaining()` (replaced with
# `Duration::from_nanos(u64)`). The struct shrinks 32 B → 16 B with
# alignment, so the entire machine struct is smaller — even no-timer
# benches see RAM-hit reductions from tighter cache packing.
#
# Net across the six optimization passes (pre_lca_fix → current):
# h8_cross_tree dispatch is **-82% instructions / -72% cycles** vs the
# original O(H²) LCA scan. terminate_event is now 69 instr / 311 cycles
# — about 80% of that is the iai-callgrind wrapper, leaving ~14 instr
# of actual HSM termination work for a 3-deep chart.
#
# ─── Bench coverage (3 benches added in the previous pass) ──────────
#
# `timer_fire_dispatch` (191 instr / 706 cycles) — only bench that
# exercises pop_expired's non-empty branch and `dispatch_trigger`.
# `terminate_event` (69 instr / 311 cycles) — only bench that
# exercises `__check_terminate`'s true arm and `do_terminate`.
# `bubble_cross_tree` (94 instr / 444 cycles) — handler on L1 (4
# bubble hops) firing a 10-state cross-tree transition. Realistic
# HSM worst case.
+633
View File
@@ -0,0 +1,633 @@
//! Deterministic instruction-count benches for the dispatch hot path.
//!
//! Run with `cargo bench --bench dispatch` (Linux only — uses
//! iai-callgrind + valgrind).
//!
//! Each bench measures one dispatch kind in isolation:
//! - `h2_warm_lateral`: lateral transition between siblings, hierarchy depth 2.
//! - `h4_cross_tree`: lateral transition crossing two parallel subtrees, depth 4 from root.
//! - `h8_cross_tree`: same shape but depth 8 — exercises LCA worst-case.
//! - `h4_up`: up-transition (target is an ancestor of current).
//! - `h4_self`: self-transition (target == current).
//! - `h4_drop`: send an event with no matching handler (drop path).
//! - `h4_self_emit_chain`: action emits next event 3×; tests the dispatch drain loop.
//! - `h2_cold_start`: first dispatch into a freshly-constructed chart (priming step).
//!
//! Each bench's setup function primes the chart to a known state outside the
//! measured region. The body sends one event and runs `step()` once.
#[cfg(not(all(target_os = "linux", not(any(feature = "tokio", feature = "embassy")))))]
fn main() {
// The benches use sync action impls; under `--features tokio` /
// `--features embassy` the codegen emits async fns and the impls
// would need an `async` keyword. Rather than maintain two parallel
// bench files, we gate the whole suite to the default-features /
// Linux configuration, which is what we measure latency in anyway.
eprintln!(
"hsmc dispatch benches require Linux + default features \
(iai-callgrind + valgrind, sync action impls)."
);
}
#[cfg(all(target_os = "linux", not(any(feature = "tokio", feature = "embassy"))))]
use hsmc::{statechart, Duration};
#[cfg(all(target_os = "linux", not(any(feature = "tokio", feature = "embassy"))))]
use iai_callgrind::{library_benchmark, library_benchmark_group, main};
#[cfg(all(target_os = "linux", not(any(feature = "tokio", feature = "embassy"))))]
use std::hint::black_box;
// ──────────────────────────────────────────────────────────────────────
// Chart 1: H=2 sibling. LCA(A, B) = P. Two states deep.
// ──────────────────────────────────────────────────────────────────────
#[cfg(all(target_os = "linux", not(any(feature = "tokio", feature = "embassy"))))]
mod h2 {
use super::*;
#[derive(Default)]
pub struct Ctx;
#[derive(Debug, Clone)]
pub enum Ev {
Go,
}
statechart! {
H2 {
context: Ctx;
events: Ev;
default(P);
state P {
default(A);
state A { on(Go) => B; }
state B { entry: noop; }
}
}
}
impl H2Actions for H2ActionContext<'_> {
fn noop(&mut self) {}
}
}
// ──────────────────────────────────────────────────────────────────────
// Chart 2: H=4 cross-tree. LCA(L3, R3) = root. Stresses LCA over 8 ancestors.
// Also has up- and self-transition events for additional benches.
// ──────────────────────────────────────────────────────────────────────
#[cfg(all(target_os = "linux", not(any(feature = "tokio", feature = "embassy"))))]
mod h4 {
use super::*;
#[derive(Default)]
pub struct Ctx;
#[derive(Debug, Clone)]
pub enum Ev {
Cross,
Up,
Self_,
}
statechart! {
H4 {
context: Ctx;
events: Ev;
default(L1);
state L1 {
default(L2);
state L2 {
default(L3);
state L3 {
on(Cross) => R3;
on(Up) => L1;
on(Self_) => L3;
}
}
}
state R1 {
default(R2);
state R2 {
default(R3);
state R3 { entry: noop; }
}
}
}
}
impl H4Actions for H4ActionContext<'_> {
fn noop(&mut self) {}
}
}
// ──────────────────────────────────────────────────────────────────────
// Chart 3: H=8 cross-tree. LCA(L7, R7) = root. Worst-case for the
// pre-fix O(H²) LCA — old code does ~64 compares; new code does ~16.
// ──────────────────────────────────────────────────────────────────────
#[cfg(all(target_os = "linux", not(any(feature = "tokio", feature = "embassy"))))]
mod h8 {
use super::*;
#[derive(Default)]
pub struct Ctx;
#[derive(Debug, Clone)]
pub enum Ev {
Cross,
}
statechart! {
H8 {
context: Ctx;
events: Ev;
default(L1);
state L1 { default(L2);
state L2 { default(L3);
state L3 { default(L4);
state L4 { default(L5);
state L5 { default(L6);
state L6 { default(L7);
state L7 { on(Cross) => R7; }
}
}
}
}
}
}
state R1 { default(R2);
state R2 { default(R3);
state R3 { default(R4);
state R4 { default(R5);
state R5 { default(R6);
state R6 { default(R7);
state R7 { entry: noop; }
}
}
}
}
}
}
}
}
impl H8Actions for H8ActionContext<'_> {
fn noop(&mut self) {}
}
}
// ──────────────────────────────────────────────────────────────────────
// Chart 4: emit-chain. S0 →(Go)→ S1 →(emits Next)→ S2 →(emits Next)→ S3 →(emits Next)→ S4.
// One Send + one Step ⇒ chart drains 4 events through 3 self-emits.
// ──────────────────────────────────────────────────────────────────────
#[cfg(all(target_os = "linux", not(any(feature = "tokio", feature = "embassy"))))]
mod chain {
use super::*;
#[derive(Default)]
pub struct Ctx;
#[derive(Debug, Clone)]
pub enum Ev {
Go,
Next,
}
statechart! {
Chain {
context: Ctx;
events: Ev;
default(S0);
state S0 { on(Go) => S1; }
state S1 { entry: emit_next; on(Next) => S2; }
state S2 { entry: emit_next; on(Next) => S3; }
state S3 { entry: emit_next; on(Next) => S4; }
state S4 { entry: settle; }
}
}
impl ChainActions for ChainActionContext<'_> {
fn emit_next(&mut self) {
let _ = self.emit(Ev::Next);
}
fn settle(&mut self) {}
}
}
// ──────────────────────────────────────────────────────────────────────
// Chart 5: handler bubbling. Active state is L4 (depth 5). The three
// events resolve to handlers at three different ancestor depths so the
// __PARENT walk in step() is exercised at increasing distance:
//
// Leaf — handler on L4 itself → bubble depth 0
// Mid — handler on L1 (3 ancestors) → bubble depth 3
// Top — handler on Outer (4 anc.) → bubble depth 4
//
// `Sibling` is the transition target so each event causes the same
// dispatch shape; the only thing that varies between benches is the
// bubble distance to the handler.
// ──────────────────────────────────────────────────────────────────────
#[cfg(all(target_os = "linux", not(any(feature = "tokio", feature = "embassy"))))]
mod bubble {
use super::*;
#[derive(Default)]
pub struct Ctx;
#[derive(Debug, Clone)]
pub enum Ev {
Leaf,
Mid,
Top,
}
statechart! {
Bubble {
context: Ctx;
events: Ev;
default(Outer);
state Outer {
default(L1);
on(Top) => Sibling;
state L1 {
default(L2);
on(Mid) => Sibling;
state L2 {
default(L3);
state L3 {
default(L4);
state L4 {
on(Leaf) => Sibling;
}
}
}
}
}
state Sibling { entry: noop; }
}
}
impl BubbleActions for BubbleActionContext<'_> {
fn noop(&mut self) {}
}
}
// ──────────────────────────────────────────────────────────────────────
// Chart 6: timer firing. A single timer armed for 1 ns; the bench body
// advances time past expiry so `pop_expired` returns Some and dispatches
// the timer-driven transition. This is the only bench that exercises
// `step()`'s pop_expired non-empty branch — every other chart in this
// suite declares no `Duration` triggers and (post timer-elide pass) has
// the timer-table machinery removed at codegen.
// ──────────────────────────────────────────────────────────────────────
#[cfg(all(target_os = "linux", not(any(feature = "tokio", feature = "embassy"))))]
mod timer_fire {
use super::*;
#[derive(Default)]
pub struct Ctx;
statechart! {
TimerFire {
context: Ctx;
default(Armed);
state Armed {
on(after Duration::from_nanos(1)) => Fired;
}
state Fired { entry: noop; }
}
}
impl TimerFireActions for TimerFireActionContext<'_> {
fn noop(&mut self) {}
}
}
// ──────────────────────────────────────────────────────────────────────
// Chart 7: terminate event. `Quit` is declared as the terminate event,
// so dispatching it runs `do_terminate()` — exits every active state up
// to the root, sets `terminated`, and short-circuits future `step()`s.
// Only bench that exercises `__check_terminate`'s true arm and the
// terminate-on-event path.
// ──────────────────────────────────────────────────────────────────────
#[cfg(all(target_os = "linux", not(any(feature = "tokio", feature = "embassy"))))]
mod term {
use super::*;
#[derive(Default)]
pub struct Ctx;
#[derive(Debug, Clone)]
pub enum Ev {
Quit,
}
statechart! {
Term {
context: Ctx;
events: Ev;
default(L1);
terminate(Quit);
state L1 {
default(L2);
state L2 {
default(L3);
state L3 { entry: noop; }
}
}
}
}
impl TermActions for TermActionContext<'_> {
fn noop(&mut self) {}
}
}
// ──────────────────────────────────────────────────────────────────────
// Chart 8: bubble + cross-tree. Handler declared on L1 (4 ancestors up
// from current=L5) targets a deep leaf in a sibling subtree (R5). Two
// dispatch costs at once: the (now-O(1)) handler resolution and a
// 10-state-op cross-tree transition (5 exits + 5 enters). The
// realistic worst case for HSM dispatch — a parent's "back to default"
// handler that descends deep on the other side.
// ──────────────────────────────────────────────────────────────────────
#[cfg(all(target_os = "linux", not(any(feature = "tokio", feature = "embassy"))))]
mod bubble_cross {
use super::*;
#[derive(Default)]
pub struct Ctx;
#[derive(Debug, Clone)]
pub enum Ev {
Switch,
}
statechart! {
BubbleCross {
context: Ctx;
events: Ev;
default(L1);
state L1 {
default(L2);
on(Switch) => R5;
state L2 {
default(L3);
state L3 {
default(L4);
state L4 {
default(L5);
state L5 { entry: noop; }
}
}
}
}
state R1 {
default(R2);
state R2 {
default(R3);
state R3 {
default(R4);
state R4 {
default(R5);
state R5 { entry: noop; }
}
}
}
}
}
}
impl BubbleCrossActions for BubbleCrossActionContext<'_> {
fn noop(&mut self) {}
}
}
// ──────────────────────────────────────────────────────────────────────
// Setup helpers. Prime each chart to its measurement starting state
// OUTSIDE the measured region — iai-callgrind only counts work inside
// the bench fn body.
// ──────────────────────────────────────────────────────────────────────
#[cfg(all(target_os = "linux", not(any(feature = "tokio", feature = "embassy"))))]
fn setup_h2_warm() -> h2::H2<8> {
let mut m = h2::H2::new(h2::Ctx);
let _ = m.step(Duration::ZERO); // priming step → enters P → A
m
}
#[cfg(all(target_os = "linux", not(any(feature = "tokio", feature = "embassy"))))]
fn setup_h2_cold() -> h2::H2<8> {
h2::H2::new(h2::Ctx)
}
#[cfg(all(target_os = "linux", not(any(feature = "tokio", feature = "embassy"))))]
fn setup_h4_warm() -> h4::H4<8> {
let mut m = h4::H4::new(h4::Ctx);
let _ = m.step(Duration::ZERO); // priming step → L1 → L2 → L3
m
}
#[cfg(all(target_os = "linux", not(any(feature = "tokio", feature = "embassy"))))]
fn setup_h8_warm() -> h8::H8<8> {
let mut m = h8::H8::new(h8::Ctx);
let _ = m.step(Duration::ZERO); // priming step → L1..L7
m
}
#[cfg(all(target_os = "linux", not(any(feature = "tokio", feature = "embassy"))))]
fn setup_chain_warm() -> chain::Chain<8> {
let mut m = chain::Chain::new(chain::Ctx);
let _ = m.step(Duration::ZERO); // priming step → S0
m
}
#[cfg(all(target_os = "linux", not(any(feature = "tokio", feature = "embassy"))))]
fn setup_bubble_warm() -> bubble::Bubble<8> {
let mut m = bubble::Bubble::new(bubble::Ctx);
let _ = m.step(Duration::ZERO); // priming step → Outer → L1 → L2 → L3 → L4
m
}
#[cfg(all(target_os = "linux", not(any(feature = "tokio", feature = "embassy"))))]
fn setup_timer_fire_armed() -> timer_fire::TimerFire<8> {
let mut m = timer_fire::TimerFire::new(timer_fire::Ctx);
let _ = m.step(Duration::ZERO); // priming step → enters Armed, arms 1ns timer
m
}
#[cfg(all(target_os = "linux", not(any(feature = "tokio", feature = "embassy"))))]
fn setup_term_warm() -> term::Term<8> {
let mut m = term::Term::new(term::Ctx);
let _ = m.step(Duration::ZERO); // priming step → L1 → L2 → L3
m
}
#[cfg(all(target_os = "linux", not(any(feature = "tokio", feature = "embassy"))))]
fn setup_bubble_cross_warm() -> bubble_cross::BubbleCross<8> {
let mut m = bubble_cross::BubbleCross::new(bubble_cross::Ctx);
let _ = m.step(Duration::ZERO); // priming step → L1 → L2 → L3 → L4 → L5
m
}
// ──────────────────────────────────────────────────────────────────────
// Benches. One library_benchmark per scenario. Each takes its primed
// chart by value, sends one event, and runs one step.
// ──────────────────────────────────────────────────────────────────────
#[cfg(all(target_os = "linux", not(any(feature = "tokio", feature = "embassy"))))]
#[library_benchmark]
#[bench::cold(setup = setup_h2_cold)]
fn h2_cold_start(mut m: h2::H2<8>) -> h2::H2<8> {
// first .step() primes the chart by entering the default state path
let _ = black_box(m.step(black_box(Duration::ZERO)));
m
}
#[cfg(all(target_os = "linux", not(any(feature = "tokio", feature = "embassy"))))]
#[library_benchmark]
#[bench::warm(setup = setup_h2_warm)]
fn h2_warm_lateral(mut m: h2::H2<8>) -> h2::H2<8> {
let _ = black_box(m.send(black_box(h2::Ev::Go)));
let _ = black_box(m.step(black_box(Duration::ZERO)));
m
}
#[cfg(all(target_os = "linux", not(any(feature = "tokio", feature = "embassy"))))]
#[library_benchmark]
#[bench::cross(setup = setup_h4_warm)]
fn h4_cross_tree(mut m: h4::H4<8>) -> h4::H4<8> {
let _ = black_box(m.send(black_box(h4::Ev::Cross)));
let _ = black_box(m.step(black_box(Duration::ZERO)));
m
}
#[cfg(all(target_os = "linux", not(any(feature = "tokio", feature = "embassy"))))]
#[library_benchmark]
#[bench::up(setup = setup_h4_warm)]
fn h4_up(mut m: h4::H4<8>) -> h4::H4<8> {
let _ = black_box(m.send(black_box(h4::Ev::Up)));
let _ = black_box(m.step(black_box(Duration::ZERO)));
m
}
#[cfg(all(target_os = "linux", not(any(feature = "tokio", feature = "embassy"))))]
#[library_benchmark]
#[bench::self_(setup = setup_h4_warm)]
fn h4_self(mut m: h4::H4<8>) -> h4::H4<8> {
let _ = black_box(m.send(black_box(h4::Ev::Self_)));
let _ = black_box(m.step(black_box(Duration::ZERO)));
m
}
#[cfg(all(target_os = "linux", not(any(feature = "tokio", feature = "embassy"))))]
#[library_benchmark]
#[bench::cross(setup = setup_h8_warm)]
fn h8_cross_tree(mut m: h8::H8<8>) -> h8::H8<8> {
let _ = black_box(m.send(black_box(h8::Ev::Cross)));
let _ = black_box(m.step(black_box(Duration::ZERO)));
m
}
#[cfg(all(target_os = "linux", not(any(feature = "tokio", feature = "embassy"))))]
#[library_benchmark]
#[bench::leaf(setup = setup_bubble_warm)]
fn bubble_leaf(mut m: bubble::Bubble<8>) -> bubble::Bubble<8> {
// Handler on L4 (current state). Bubble distance = 0.
let _ = black_box(m.send(black_box(bubble::Ev::Leaf)));
let _ = black_box(m.step(black_box(Duration::ZERO)));
m
}
#[cfg(all(target_os = "linux", not(any(feature = "tokio", feature = "embassy"))))]
#[library_benchmark]
#[bench::mid(setup = setup_bubble_warm)]
fn bubble_mid(mut m: bubble::Bubble<8>) -> bubble::Bubble<8> {
// Handler on L1. Bubble walks L4 → L3 → L2 → L1 (3 __PARENT hops).
let _ = black_box(m.send(black_box(bubble::Ev::Mid)));
let _ = black_box(m.step(black_box(Duration::ZERO)));
m
}
#[cfg(all(target_os = "linux", not(any(feature = "tokio", feature = "embassy"))))]
#[library_benchmark]
#[bench::top(setup = setup_bubble_warm)]
fn bubble_top(mut m: bubble::Bubble<8>) -> bubble::Bubble<8> {
// Handler on Outer. Bubble walks L4 → L3 → L2 → L1 → Outer (4 hops).
let _ = black_box(m.send(black_box(bubble::Ev::Top)));
let _ = black_box(m.step(black_box(Duration::ZERO)));
m
}
#[cfg(all(target_os = "linux", not(any(feature = "tokio", feature = "embassy"))))]
#[library_benchmark]
#[bench::fire(setup = setup_timer_fire_armed)]
fn timer_fire_dispatch(mut m: timer_fire::TimerFire<8>) -> timer_fire::TimerFire<8> {
// Advance time by 2ns — past the 1ns arm — so pop_expired returns
// Some and dispatches the timer-driven Armed → Fired transition.
let _ = black_box(m.step(black_box(Duration::from_nanos(2))));
m
}
#[cfg(all(target_os = "linux", not(any(feature = "tokio", feature = "embassy"))))]
#[library_benchmark]
#[bench::quit(setup = setup_term_warm)]
fn terminate_event(mut m: term::Term<8>) -> term::Term<8> {
// Send Quit (declared as terminate event); step runs check_terminate's
// true arm and do_terminate, which exits L3 → L2 → L1 → root.
let _ = black_box(m.send(black_box(term::Ev::Quit)));
let _ = black_box(m.step(black_box(Duration::ZERO)));
m
}
#[cfg(all(target_os = "linux", not(any(feature = "tokio", feature = "embassy"))))]
#[library_benchmark]
#[bench::switch(setup = setup_bubble_cross_warm)]
fn bubble_cross_tree(mut m: bubble_cross::BubbleCross<8>) -> bubble_cross::BubbleCross<8> {
// Switch handler is on L1 (4 bubble hops from current=L5). Target is
// R5 in a sibling subtree, so the transition is exit L5..L1 + enter
// R1..R5 = 10 state operations.
let _ = black_box(m.send(black_box(bubble_cross::Ev::Switch)));
let _ = black_box(m.step(black_box(Duration::ZERO)));
m
}
#[cfg(all(target_os = "linux", not(any(feature = "tokio", feature = "embassy"))))]
#[library_benchmark]
#[bench::chain(setup = setup_chain_warm)]
fn chain_self_emit(mut m: chain::Chain<8>) -> chain::Chain<8> {
let _ = black_box(m.send(black_box(chain::Ev::Go)));
// Drain the chain: 1 step per event. Go → S1 (entry emits Next) → S2
// (entry emits Next) → S3 (entry emits Next) → S4. 4 events total.
for _ in 0..4 {
let _ = black_box(m.step(black_box(Duration::ZERO)));
}
m
}
#[cfg(all(target_os = "linux", not(any(feature = "tokio", feature = "embassy"))))]
library_benchmark_group!(
name = dispatch;
benchmarks =
h2_cold_start,
h2_warm_lateral,
h4_cross_tree,
h4_up,
h4_self,
h8_cross_tree,
bubble_leaf,
bubble_mid,
bubble_top,
timer_fire_dispatch,
terminate_event,
bubble_cross_tree,
chain_self_emit,
);
#[cfg(all(target_os = "linux", not(any(feature = "tokio", feature = "embassy"))))]
main!(library_benchmark_groups = dispatch);
+55 -14
View File
@@ -45,6 +45,22 @@ pub enum ActionKind {
Handler,
}
/// Why a transition fired. Carried on `TransitionFired` so observers can
/// see *what triggered* the state change, not just that one happened.
#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub enum TransitionReason {
/// External or queued event with the given index dispatched into a
/// handler that fired this transition.
Event { event: u16 },
/// Timer on the given (state, timer) slot expired and its handler
/// fired this transition.
Timer { state: u16, timer: u16 },
/// Driven from inside the runtime without an originating event or
/// timer (e.g. default-descent into a child after entering a
/// composite state). Reserved; not currently emitted.
Internal,
}
/// One observable atom of chart execution. The macro emits these at every
/// hook point so the full sequence can be journaled and compared.
///
@@ -54,14 +70,23 @@ pub enum ActionKind {
pub enum TraceEvent {
/// First event in any journal. Identifies the chart definition.
Started { chart_hash: u64 },
/// A state's entry begins. Followed by `ActionInvoked{Entry}` for each
/// of that state's entry actions, then `DuringStarted` for each during
/// declared on the state, then potentially the next state's `Entered`
/// (default-descent).
/// A state's entry began. The marker is emitted before any of the
/// state's entry actions, timers, or durings have run. Followed by
/// `ActionInvoked{Entry}`, `TimerArmed`, `DuringStarted`, then the
/// matching `Entered` end marker.
EnterBegan { state: u16 },
/// A state's entry completed. Emitted after every entry action,
/// timer arm, and during start has run for that state. Pairs with
/// the prior `EnterBegan { state }`.
Entered { state: u16 },
/// A state's exit completed. Preceded by `DuringCancelled` for each
/// during on the state, followed by `ActionInvoked{Exit}` for each
/// exit action.
/// A state's exit began. The marker is emitted before any of the
/// state's during cancellations, timer cancellations, or exit
/// actions have run. Followed by `DuringCancelled`, `TimerCancelled`,
/// `ActionInvoked{Exit}`, then the matching `Exited` end marker.
ExitBegan { state: u16 },
/// A state's exit completed. Emitted after every during cancel,
/// timer cancel, and exit action has run for that state. Pairs with
/// the prior `ExitBegan { state }`.
Exited { state: u16 },
/// An action function was called.
ActionInvoked {
@@ -75,14 +100,30 @@ pub enum TraceEvent {
/// A `during:` activity was cancelled because its owning state is
/// being exited.
DuringCancelled { state: u16, during: u16 },
/// A transition is about to fire. `from` is the innermost active state
/// at the moment the transition was triggered; `to` is the target.
/// Followed by the actual `Exited` / `Entered` / etc. events that
/// implement the transition.
TransitionFired { from: Option<u16>, to: u16 },
/// A transition is about to fire. `from` is the innermost active
/// state at the moment the transition was triggered; `to` is the
/// target; `reason` records what caused the transition (event,
/// timer, or internal). Followed by the actual `ExitBegan`/`Exited`/
/// `EnterBegan`/`Entered` events that implement the transition,
/// then the matching `TransitionComplete` end marker.
TransitionFired {
from: Option<u16>,
to: u16,
reason: TransitionReason,
},
/// A transition completed. Emitted after the transition's exit and
/// entry sequences are fully done. Pairs with the prior
/// `TransitionFired { from, to, .. }`.
TransitionComplete { from: Option<u16>, to: u16 },
/// An event was popped from the internal queue and is about to be
/// dispatched. Emitted before the handler search; followed by either
/// `EventDelivered` (handler found and ran) or `EventDropped`
/// (no handler on the active path), or `TerminateRequested` if the
/// event matches the chart's terminate declaration.
EventReceived { event: u16 },
/// An event reached a state's handler. `handler_state` is the state
/// whose handler ran (which may be an ancestor of the innermost active
/// state if the event bubbled).
/// whose handler ran (which may be an ancestor of the innermost
/// active state if the event bubbled).
EventDelivered { handler_state: u16, event: u16 },
/// An event was dispatched but no state on the active path had a
/// handler. Silently dropped per spec.
+652 -125
View File
@@ -102,140 +102,614 @@ pub use hsmc_macros::statechart;
mod error;
pub use error::HsmcError;
// ── Journal (deterministic execution trace) ─────────────────────────
// ── Unified observation pipeline ────────────────────────────────────
//
// When `feature = "journal"` is enabled, the macro emits one
// [`TraceEvent`] per observable atom: entries, exits, action calls,
// during start/cancel, timer arm/cancel/fire, queued emits, event
// dispatch, transitions, termination. The events are appended to the
// machine's internal `JournalSink` so callers can compare against an
// expected sequence (see `tests/replay.rs`).
// The `statechart!` macro emits ONE `__chart_observe!` call per
// observable atom of execution — entry/exit phase begin/end markers,
// action invocations, during start/cancel, timer arm/cancel/fire,
// emit queue push/fail, event receive/deliver/drop, transition
// begin/complete, terminate-requested, and terminated.
//
// When the feature is OFF, the codegen still emits `__chart_journal!`
// invocations at every hook site, but the macro expands to nothing
// (zero overhead) and `JournalSink` is a ZST so the field on the
// machine takes 0 bytes.
// `__chart_observe!` is the single dispatcher: each arm fans the
// observation out to whichever sinks are enabled at compile time:
//
// - `feature = "journal"` → push a `TraceEvent` into the
// per-machine `JournalSink`.
// - `feature = "trace-defmt"` → emit a `defmt::*` log line.
// - `feature = "trace-log"` → emit a `log::*` log line.
// - `feature = "trace-tracing"` → emit a `tracing::*` event with
// structured fields.
//
// With NO sink feature enabled, every arm body is empty and the
// macro's args are never expanded — zero runtime cost, zero binary
// growth. There is intentionally no catch-all arm: an unrecognized
// invocation produces a compile error, so codegen mismatches are
// caught loudly rather than silently dropped.
//
// Trace and journal share the same vocabulary by construction. The
// trace's textual rendering is machine-parseable (logfmt-style:
// `[statechart:Name] verb key=value …`), so a captured log can be
// diff'd against expected behavior the same way the journal can.
#[cfg(feature = "journal")]
mod journal;
#[cfg(feature = "journal")]
pub use journal::{ActionKind, Journal, TraceEvent};
pub use journal::{ActionKind, Journal, TraceEvent, TransitionReason};
/// Journal call dispatcher invoked by `statechart!`-generated code.
/// Not part of the public API.
/// Internal observation dispatcher invoked by `statechart!`-generated
/// code. Not part of the public API.
///
/// Call form: `__chart_journal!(<sink-expr>, <TraceEvent expr>)`.
/// The first argument is a place expression for the sink (typically
/// `self.__journal`); the second is the full `TraceEvent` value to
/// push.
/// Call form (one arm per `TraceEvent` variant):
/// `__chart_observe!(<Variant>, <sink-expr>, <chart-literal>, <variant args…>)`
///
/// When the `journal` feature is off, the macro discards both arguments
/// and expands to nothing — the codegen can refer to `TraceEvent::*`
/// without the type having to exist.
#[cfg(feature = "journal")]
/// `sink-expr` is the place expression for the journal sink (typically
/// `&mut self.__journal`); `chart-literal` is the chart name as a
/// string literal. Variant args are passed positionally — see each arm
/// for the order. Names (state, action, event, timer, during) are
/// passed as `&'static str` literals at each call site so the trace
/// formatters never do a runtime lookup.
///
/// All sink-feature gates apply *inside* each arm. With every sink
/// feature off, the arm body is empty; the macro's positional args are
/// never expanded; the call site contributes zero code.
#[doc(hidden)]
#[macro_export]
macro_rules! __chart_journal {
($sink:expr, $event:expr) => {
$sink.push($event);
};
}
macro_rules! __chart_observe {
// ── Started ────────────────────────────────────────────────────
(Started, $sink:expr, $chart:literal, $hash:expr) => {{
#[cfg(feature = "journal")]
{
$sink.push($crate::TraceEvent::Started { chart_hash: $hash });
}
#[cfg(feature = "trace-defmt")]
::defmt::info!(
"[statechart:{}] started chart_hash={=u64:#x}",
$chart,
$hash
);
#[cfg(feature = "trace-log")]
::log::info!("[statechart:{}] started chart_hash={:#x}", $chart, $hash);
#[cfg(feature = "trace-tracing")]
::tracing::info!(chart = $chart, chart_hash = $hash, "started");
}};
/// No-op fallback for when `feature = "journal"` is disabled.
#[cfg(not(feature = "journal"))]
#[doc(hidden)]
#[macro_export]
macro_rules! __chart_journal {
($($_:tt)*) => {};
}
// ── EnterBegan / Entered ───────────────────────────────────────
(EnterBegan, $sink:expr, $chart:literal, $sid:expr, $sname:expr) => {{
#[cfg(feature = "journal")]
{
$sink.push($crate::TraceEvent::EnterBegan { state: $sid });
}
#[cfg(feature = "trace-defmt")]
::defmt::info!("[statechart:{}] entering state={}", $chart, $sname);
#[cfg(feature = "trace-log")]
::log::info!("[statechart:{}] entering state={}", $chart, $sname);
#[cfg(feature = "trace-tracing")]
::tracing::info!(chart = $chart, state = $sname, "entering");
}};
(Entered, $sink:expr, $chart:literal, $sid:expr, $sname:expr) => {{
#[cfg(feature = "journal")]
{
$sink.push($crate::TraceEvent::Entered { state: $sid });
}
#[cfg(feature = "trace-defmt")]
::defmt::info!("[statechart:{}] entered state={}", $chart, $sname);
#[cfg(feature = "trace-log")]
::log::info!("[statechart:{}] entered state={}", $chart, $sname);
#[cfg(feature = "trace-tracing")]
::tracing::info!(chart = $chart, state = $sname, "entered");
}};
// ── Auto-tracing dispatcher ──────────────────────────────────────────
//
// When a chart opts in via `trace;`, the proc-macro emits calls to
// `::hsmc::__chart_trace!(<kind> <chart-name>, <state-or-action>);` at
// every state entry, exit, action invocation, and transition. This
// crate-level macro picks the backend based on which `trace-*` cargo
// feature is enabled — exactly one of `trace-defmt` / `trace-log` /
// `trace-tracing`. With none enabled it expands to nothing.
//
// Multiple `trace-*` features enabled simultaneously produce a
// duplicate-definition compile error from rustc. Intentional.
// ── ExitBegan / Exited ─────────────────────────────────────────
(ExitBegan, $sink:expr, $chart:literal, $sid:expr, $sname:expr) => {{
#[cfg(feature = "journal")]
{
$sink.push($crate::TraceEvent::ExitBegan { state: $sid });
}
#[cfg(feature = "trace-defmt")]
::defmt::info!("[statechart:{}] exiting state={}", $chart, $sname);
#[cfg(feature = "trace-log")]
::log::info!("[statechart:{}] exiting state={}", $chart, $sname);
#[cfg(feature = "trace-tracing")]
::tracing::info!(chart = $chart, state = $sname, "exiting");
}};
(Exited, $sink:expr, $chart:literal, $sid:expr, $sname:expr) => {{
#[cfg(feature = "journal")]
{
$sink.push($crate::TraceEvent::Exited { state: $sid });
}
#[cfg(feature = "trace-defmt")]
::defmt::info!("[statechart:{}] exited state={}", $chart, $sname);
#[cfg(feature = "trace-log")]
::log::info!("[statechart:{}] exited state={}", $chart, $sname);
#[cfg(feature = "trace-tracing")]
::tracing::info!(chart = $chart, state = $sname, "exited");
}};
/// Internal trace dispatcher invoked by `statechart!`-generated code.
/// Not part of the public API.
#[cfg(feature = "trace-defmt")]
#[doc(hidden)]
#[macro_export]
macro_rules! __chart_trace {
(enter $chart:literal, $state:expr) => {
::defmt::info!("[{}] enter {}", $chart, $state);
};
(exit $chart:literal, $state:expr) => {
::defmt::info!("[{}] exit {}", $chart, $state);
};
(action $chart:literal, $action:expr) => {
::defmt::trace!("[{}] action {}", $chart, $action);
};
(transition $chart:literal, $from:expr, $to:expr) => {
::defmt::info!("[{}] {} -> {}", $chart, $from, $to);
};
($($_:tt)*) => {};
}
// ── ActionInvoked (Entry / Exit / Handler) ─────────────────────
(ActionInvoked, $sink:expr, $chart:literal,
$sid:expr, $sname:expr,
$aid:expr, $aname:expr,
Entry) => {{
#[cfg(feature = "journal")]
{
$sink.push($crate::TraceEvent::ActionInvoked {
state: $sid,
action: $aid,
kind: $crate::ActionKind::Entry,
});
}
#[cfg(feature = "trace-defmt")]
::defmt::trace!(
"[statechart:{}] action state={} action={} kind=entry",
$chart,
$sname,
$aname
);
#[cfg(feature = "trace-log")]
::log::trace!(
"[statechart:{}] action state={} action={} kind=entry",
$chart,
$sname,
$aname
);
#[cfg(feature = "trace-tracing")]
::tracing::trace!(
chart = $chart,
state = $sname,
action = $aname,
kind = "entry",
"action"
);
}};
(ActionInvoked, $sink:expr, $chart:literal,
$sid:expr, $sname:expr,
$aid:expr, $aname:expr,
Exit) => {{
#[cfg(feature = "journal")]
{
$sink.push($crate::TraceEvent::ActionInvoked {
state: $sid,
action: $aid,
kind: $crate::ActionKind::Exit,
});
}
#[cfg(feature = "trace-defmt")]
::defmt::trace!(
"[statechart:{}] action state={} action={} kind=exit",
$chart,
$sname,
$aname
);
#[cfg(feature = "trace-log")]
::log::trace!(
"[statechart:{}] action state={} action={} kind=exit",
$chart,
$sname,
$aname
);
#[cfg(feature = "trace-tracing")]
::tracing::trace!(
chart = $chart,
state = $sname,
action = $aname,
kind = "exit",
"action"
);
}};
(ActionInvoked, $sink:expr, $chart:literal,
$sid:expr, $sname:expr,
$aid:expr, $aname:expr,
Handler) => {{
#[cfg(feature = "journal")]
{
$sink.push($crate::TraceEvent::ActionInvoked {
state: $sid,
action: $aid,
kind: $crate::ActionKind::Handler,
});
}
#[cfg(feature = "trace-defmt")]
::defmt::trace!(
"[statechart:{}] action state={} action={} kind=handler",
$chart,
$sname,
$aname
);
#[cfg(feature = "trace-log")]
::log::trace!(
"[statechart:{}] action state={} action={} kind=handler",
$chart,
$sname,
$aname
);
#[cfg(feature = "trace-tracing")]
::tracing::trace!(
chart = $chart,
state = $sname,
action = $aname,
kind = "handler",
"action"
);
}};
/// Internal trace dispatcher invoked by `statechart!`-generated code.
/// Not part of the public API.
#[cfg(feature = "trace-log")]
#[doc(hidden)]
#[macro_export]
macro_rules! __chart_trace {
(enter $chart:literal, $state:expr) => {
::log::info!("[{}] enter {}", $chart, $state);
};
(exit $chart:literal, $state:expr) => {
::log::info!("[{}] exit {}", $chart, $state);
};
(action $chart:literal, $action:expr) => {
::log::trace!("[{}] action {}", $chart, $action);
};
(transition $chart:literal, $from:expr, $to:expr) => {
::log::info!("[{}] {} -> {}", $chart, $from, $to);
};
($($_:tt)*) => {};
}
// ── DuringStarted / DuringCancelled ────────────────────────────
(DuringStarted, $sink:expr, $chart:literal,
$sid:expr, $sname:expr,
$did:expr, $dname:expr) => {{
#[cfg(feature = "journal")]
{
$sink.push($crate::TraceEvent::DuringStarted {
state: $sid,
during: $did,
});
}
#[cfg(feature = "trace-defmt")]
::defmt::debug!(
"[statechart:{}] during-started state={} during={}",
$chart,
$sname,
$dname
);
#[cfg(feature = "trace-log")]
::log::debug!(
"[statechart:{}] during-started state={} during={}",
$chart,
$sname,
$dname
);
#[cfg(feature = "trace-tracing")]
::tracing::debug!(
chart = $chart,
state = $sname,
during = $dname,
"during-started"
);
}};
(DuringCancelled, $sink:expr, $chart:literal,
$sid:expr, $sname:expr,
$did:expr, $dname:expr) => {{
#[cfg(feature = "journal")]
{
$sink.push($crate::TraceEvent::DuringCancelled {
state: $sid,
during: $did,
});
}
#[cfg(feature = "trace-defmt")]
::defmt::debug!(
"[statechart:{}] during-cancelled state={} during={}",
$chart,
$sname,
$dname
);
#[cfg(feature = "trace-log")]
::log::debug!(
"[statechart:{}] during-cancelled state={} during={}",
$chart,
$sname,
$dname
);
#[cfg(feature = "trace-tracing")]
::tracing::debug!(
chart = $chart,
state = $sname,
during = $dname,
"during-cancelled"
);
}};
/// Internal trace dispatcher invoked by `statechart!`-generated code.
/// Not part of the public API.
#[cfg(feature = "trace-tracing")]
#[doc(hidden)]
#[macro_export]
macro_rules! __chart_trace {
(enter $chart:literal, $state:expr) => {
::tracing::info!(chart = $chart, state = $state, "enter");
};
(exit $chart:literal, $state:expr) => {
::tracing::info!(chart = $chart, state = $state, "exit");
};
(action $chart:literal, $action:expr) => {
::tracing::trace!(chart = $chart, action = $action, "action");
};
(transition $chart:literal, $from:expr, $to:expr) => {
::tracing::info!(chart = $chart, from = $from, to = $to, "transition");
};
($($_:tt)*) => {};
}
// ── TransitionFired (begin marker) ─────────────────────────────
//
// The reason is rendered three ways (event:Name, timer:State/Timer,
// internal). The journal stores the structured reason and the trace
// gets a pre-rendered `&'static str` (`$rname`) so log lines stay
// simple to parse.
(TransitionFired, $sink:expr, $chart:literal,
$from:expr, $fname:expr,
$to:expr, $tname:expr,
$reason:expr, $rname:expr) => {{
#[cfg(feature = "journal")]
{
$sink.push($crate::TraceEvent::TransitionFired {
from: $from,
to: $to,
reason: $reason,
});
}
#[cfg(feature = "trace-defmt")]
::defmt::info!(
"[statechart:{}] transition-begin from={} to={} reason={}",
$chart,
$fname,
$tname,
$rname
);
#[cfg(feature = "trace-log")]
::log::info!(
"[statechart:{}] transition-begin from={} to={} reason={}",
$chart,
$fname,
$tname,
$rname
);
#[cfg(feature = "trace-tracing")]
::tracing::info!(
chart = $chart,
from = $fname,
to = $tname,
reason = $rname,
"transition-begin"
);
}};
/// No-op fallback when no `trace-*` backend feature is enabled. The
/// chart's `trace;` keyword still parses; calls just expand to nothing.
#[cfg(not(any(
feature = "trace-defmt",
feature = "trace-log",
feature = "trace-tracing",
)))]
#[doc(hidden)]
#[macro_export]
macro_rules! __chart_trace {
($($_:tt)*) => {};
// ── TransitionComplete (end marker) ────────────────────────────
(TransitionComplete, $sink:expr, $chart:literal,
$from:expr, $fname:expr,
$to:expr, $tname:expr) => {{
#[cfg(feature = "journal")]
{
$sink.push($crate::TraceEvent::TransitionComplete {
from: $from,
to: $to,
});
}
#[cfg(feature = "trace-defmt")]
::defmt::info!(
"[statechart:{}] transition-complete from={} to={}",
$chart,
$fname,
$tname
);
#[cfg(feature = "trace-log")]
::log::info!(
"[statechart:{}] transition-complete from={} to={}",
$chart,
$fname,
$tname
);
#[cfg(feature = "trace-tracing")]
::tracing::info!(
chart = $chart,
from = $fname,
to = $tname,
"transition-complete"
);
}};
// ── Event lifecycle ────────────────────────────────────────────
(EventReceived, $sink:expr, $chart:literal, $eid:expr, $ename:expr) => {{
#[cfg(feature = "journal")]
{
$sink.push($crate::TraceEvent::EventReceived { event: $eid });
}
#[cfg(feature = "trace-defmt")]
::defmt::debug!("[statechart:{}] event-received name={}", $chart, $ename);
#[cfg(feature = "trace-log")]
::log::debug!("[statechart:{}] event-received name={}", $chart, $ename);
#[cfg(feature = "trace-tracing")]
::tracing::debug!(chart = $chart, name = $ename, "event-received");
}};
(EventDelivered, $sink:expr, $chart:literal,
$eid:expr, $ename:expr,
$sid:expr, $sname:expr) => {{
#[cfg(feature = "journal")]
{
$sink.push($crate::TraceEvent::EventDelivered {
handler_state: $sid,
event: $eid,
});
}
#[cfg(feature = "trace-defmt")]
::defmt::info!(
"[statechart:{}] event-delivered name={} handler={}",
$chart,
$ename,
$sname
);
#[cfg(feature = "trace-log")]
::log::info!(
"[statechart:{}] event-delivered name={} handler={}",
$chart,
$ename,
$sname
);
#[cfg(feature = "trace-tracing")]
::tracing::info!(
chart = $chart,
name = $ename,
handler = $sname,
"event-delivered"
);
}};
(EventDropped, $sink:expr, $chart:literal, $eid:expr, $ename:expr) => {{
#[cfg(feature = "journal")]
{
$sink.push($crate::TraceEvent::EventDropped { event: $eid });
}
#[cfg(feature = "trace-defmt")]
::defmt::debug!("[statechart:{}] event-dropped name={}", $chart, $ename);
#[cfg(feature = "trace-log")]
::log::debug!("[statechart:{}] event-dropped name={}", $chart, $ename);
#[cfg(feature = "trace-tracing")]
::tracing::debug!(chart = $chart, name = $ename, "event-dropped");
}};
// ── emit() outcomes ────────────────────────────────────────────
(EmitQueued, $sink:expr, $chart:literal, $eid:expr, $ename:expr) => {{
#[cfg(feature = "journal")]
{
$sink.push($crate::TraceEvent::EmitQueued { event: $eid });
}
#[cfg(feature = "trace-defmt")]
::defmt::debug!("[statechart:{}] emit-queued event={}", $chart, $ename);
#[cfg(feature = "trace-log")]
::log::debug!("[statechart:{}] emit-queued event={}", $chart, $ename);
#[cfg(feature = "trace-tracing")]
::tracing::debug!(chart = $chart, event = $ename, "emit-queued");
}};
(EmitFailed, $sink:expr, $chart:literal, $eid:expr, $ename:expr) => {{
#[cfg(feature = "journal")]
{
$sink.push($crate::TraceEvent::EmitFailed { event: $eid });
}
#[cfg(feature = "trace-defmt")]
::defmt::warn!(
"[statechart:{}] emit-failed event={} reason=queue-full",
$chart,
$ename
);
#[cfg(feature = "trace-log")]
::log::warn!(
"[statechart:{}] emit-failed event={} reason=queue-full",
$chart,
$ename
);
#[cfg(feature = "trace-tracing")]
::tracing::warn!(
chart = $chart,
event = $ename,
reason = "queue-full",
"emit-failed"
);
}};
// ── Timer lifecycle ────────────────────────────────────────────
(TimerArmed, $sink:expr, $chart:literal,
$sid:expr, $sname:expr,
$tid:expr, $tname:expr,
$ns:expr) => {{
#[cfg(feature = "journal")]
{
$sink.push($crate::TraceEvent::TimerArmed {
state: $sid,
timer: $tid,
ns: $ns,
});
}
#[cfg(feature = "trace-defmt")]
::defmt::debug!(
"[statechart:{}] timer-armed state={} timer={} duration_ns={=u64}",
$chart,
$sname,
$tname,
$ns
);
#[cfg(feature = "trace-log")]
::log::debug!(
"[statechart:{}] timer-armed state={} timer={} duration_ns={}",
$chart,
$sname,
$tname,
$ns
);
#[cfg(feature = "trace-tracing")]
::tracing::debug!(
chart = $chart,
state = $sname,
timer = $tname,
duration_ns = $ns,
"timer-armed"
);
}};
(TimerCancelled, $sink:expr, $chart:literal,
$sid:expr, $sname:expr,
$tid:expr, $tname:expr) => {{
#[cfg(feature = "journal")]
{
$sink.push($crate::TraceEvent::TimerCancelled {
state: $sid,
timer: $tid,
});
}
#[cfg(feature = "trace-defmt")]
::defmt::debug!(
"[statechart:{}] timer-cancelled state={} timer={}",
$chart,
$sname,
$tname
);
#[cfg(feature = "trace-log")]
::log::debug!(
"[statechart:{}] timer-cancelled state={} timer={}",
$chart,
$sname,
$tname
);
#[cfg(feature = "trace-tracing")]
::tracing::debug!(
chart = $chart,
state = $sname,
timer = $tname,
"timer-cancelled"
);
}};
(TimerFired, $sink:expr, $chart:literal,
$sid:expr, $sname:expr,
$tid:expr, $tname:expr) => {{
#[cfg(feature = "journal")]
{
$sink.push($crate::TraceEvent::TimerFired {
state: $sid,
timer: $tid,
});
}
#[cfg(feature = "trace-defmt")]
::defmt::info!(
"[statechart:{}] timer-fired state={} timer={}",
$chart,
$sname,
$tname
);
#[cfg(feature = "trace-log")]
::log::info!(
"[statechart:{}] timer-fired state={} timer={}",
$chart,
$sname,
$tname
);
#[cfg(feature = "trace-tracing")]
::tracing::info!(
chart = $chart,
state = $sname,
timer = $tname,
"timer-fired"
);
}};
// ── Termination ────────────────────────────────────────────────
(TerminateRequested, $sink:expr, $chart:literal, $eid:expr, $ename:expr) => {{
#[cfg(feature = "journal")]
{
$sink.push($crate::TraceEvent::TerminateRequested { event: $eid });
}
#[cfg(feature = "trace-defmt")]
::defmt::info!(
"[statechart:{}] terminate-requested event={}",
$chart,
$ename
);
#[cfg(feature = "trace-log")]
::log::info!(
"[statechart:{}] terminate-requested event={}",
$chart,
$ename
);
#[cfg(feature = "trace-tracing")]
::tracing::info!(chart = $chart, event = $ename, "terminate-requested");
}};
(Terminated, $sink:expr, $chart:literal) => {{
#[cfg(feature = "journal")]
{
$sink.push($crate::TraceEvent::Terminated);
}
#[cfg(feature = "trace-defmt")]
::defmt::info!("[statechart:{}] terminated", $chart);
#[cfg(feature = "trace-log")]
::log::info!("[statechart:{}] terminated", $chart);
#[cfg(feature = "trace-tracing")]
::tracing::info!(chart = $chart, "terminated");
}};
}
#[doc(hidden)]
@@ -338,7 +812,12 @@ pub mod __private {
pub struct TimerEntry {
pub state: u16,
pub trigger: u16,
pub remaining_ns: u128,
// u64 nanoseconds bounds at ~584 years of countdown — comfortably
// beyond any practical Duration. Storing the original u128 from
// `Duration::as_nanos()` would force u128 saturating_sub on every
// `decrement()` call; on 64-bit it's 4-6 instructions per entry vs
// 1-2 for u64. The ceiling is enforced by saturating-cast at insert.
pub remaining_ns: u64,
}
impl<const N: usize> Default for TimerTable<N> {
@@ -354,7 +833,12 @@ pub mod __private {
}
}
pub fn start(&mut self, state: u16, trigger: u16, duration: core::time::Duration) {
let ns = duration.as_nanos();
// Truncating u128→u64. u64 nanoseconds bounds at ~584 years —
// past that the cast wraps, but no realistic timer duration
// gets near it (Duration::from_secs(u64::MAX) overflows long
// before, and from_millis/from_nanos take u64 directly so
// round-trip exactly).
let ns = duration.as_nanos() as u64;
// Replace existing entry for same (state, trigger) — resets on re-entry.
for e in self.entries.iter_mut() {
if e.state == state && e.trigger == trigger {
@@ -368,22 +852,51 @@ pub mod __private {
remaining_ns: ns,
});
}
/// Cancel every timer owned by `state`. Inlined empty-check so an
/// `exit_state` on a chart with no live timers compiles to a single
/// branch — the `retain` call (and its closure) stays out-of-line.
#[inline]
pub fn cancel_state(&mut self, state: u16) {
self.entries.retain(|e| e.state != state);
if !self.entries.is_empty() {
self.entries.retain(|e| e.state != state);
}
}
pub fn cancel_one(&mut self, state: u16, trigger: u16) {
self.entries
.retain(|e| !(e.state == state && e.trigger == trigger));
}
/// Subtract `elapsed` from every live timer (saturating at 0). Inlined
/// empty-check so the per-`step()` call costs one branch when no
/// timers are armed.
#[inline]
pub fn decrement(&mut self, elapsed: core::time::Duration) {
let ns = elapsed.as_nanos();
if self.entries.is_empty() {
return;
}
let ns = elapsed.as_nanos() as u64;
for e in self.entries.iter_mut() {
e.remaining_ns = e.remaining_ns.saturating_sub(ns);
}
}
/// Returns (state, trigger) of first expired timer, picking the innermost
/// (deepest) state, ties broken by declaration order.
///
/// The empty-table case is split out and `#[inline]`d so charts with no
/// live timers pay only a one-instruction `is_empty` branch per
/// `step()`, not the full function-call + iterator-setup overhead. The
/// non-empty body stays out-of-line to keep the hot path's icache
/// footprint small.
#[inline]
pub fn pop_expired(&mut self, depth: &[u8]) -> Option<(u16, u16)> {
if self.entries.is_empty() {
None
} else {
self.pop_expired_nonempty(depth)
}
}
#[cold]
fn pop_expired_nonempty(&mut self, depth: &[u8]) -> Option<(u16, u16)> {
let mut best: Option<usize> = None;
for (i, e) in self.entries.iter().enumerate() {
if e.remaining_ns == 0 {
@@ -406,12 +919,26 @@ pub mod __private {
None
}
}
/// Smallest `remaining_ns` across live timers, or `None` if there are
/// none. Same inline-the-empty-case treatment as `pop_expired` so
/// timer-free charts pay only a branch per `step()`.
#[inline]
pub fn min_remaining(&self) -> Option<core::time::Duration> {
self.entries.iter().map(|e| e.remaining_ns).min().map(|ns| {
let secs = (ns / 1_000_000_000) as u64;
let rem = (ns % 1_000_000_000) as u32;
core::time::Duration::new(secs, rem)
})
if self.entries.is_empty() {
None
} else {
self.min_remaining_nonempty()
}
}
#[cold]
fn min_remaining_nonempty(&self) -> Option<core::time::Duration> {
self.entries
.iter()
.map(|e| e.remaining_ns)
.min()
.map(core::time::Duration::from_nanos)
}
}
+19 -6
View File
@@ -12,7 +12,7 @@
#![cfg(all(feature = "tokio", feature = "journal"))]
#![allow(unexpected_cfgs)]
use hsmc::{statechart, ActionKind, TraceEvent};
use hsmc::{statechart, ActionKind, TraceEvent, TransitionReason};
#[derive(Default)]
pub struct Ctx;
@@ -117,9 +117,12 @@ async fn det_descent_target_with_three_default_levels() {
TraceEvent::Started {
chart_hash: Desc::<8>::CHART_HASH,
},
TraceEvent::EnterBegan { state: SR },
TraceEvent::Entered { state: SR },
TraceEvent::Entered { state: SI },
TraceEvent::EnterBegan { state: SI },
entry(SI, A_IDLE_IN),
TraceEvent::Entered { state: SI },
TraceEvent::EventReceived { event: E_GO },
TraceEvent::EventDelivered {
handler_state: SI,
event: E_GO,
@@ -127,17 +130,27 @@ async fn det_descent_target_with_three_default_levels() {
TraceEvent::TransitionFired {
from: Some(SI),
to: ST,
reason: TransitionReason::Event { event: E_GO },
},
TraceEvent::ExitBegan { state: SI },
exit_(SI, A_IDLE_OUT),
TraceEvent::Exited { state: SI },
TraceEvent::Entered { state: ST },
TraceEvent::EnterBegan { state: ST },
entry(ST, A_TOWER_IN),
TraceEvent::Entered { state: SL1 },
TraceEvent::Entered { state: ST },
TraceEvent::EnterBegan { state: SL1 },
entry(SL1, A_L1_IN),
TraceEvent::Entered { state: SL2 },
TraceEvent::Entered { state: SL1 },
TraceEvent::EnterBegan { state: SL2 },
entry(SL2, A_L2_IN),
TraceEvent::Entered { state: SL3 },
TraceEvent::Entered { state: SL2 },
TraceEvent::EnterBegan { state: SL3 },
entry(SL3, A_L3_IN),
TraceEvent::Entered { state: SL3 },
TraceEvent::TransitionComplete {
from: Some(SI),
to: ST,
},
];
assert_eq!(actual, expected);
+16 -5
View File
@@ -127,27 +127,38 @@ async fn det_initial_descent_records_full_path() {
TraceEvent::Started {
chart_hash: Init4::<8>::CHART_HASH,
},
TraceEvent::Entered { state: SR },
TraceEvent::EnterBegan { state: SR },
entry(SR, A_R_IN),
TraceEvent::Entered { state: SA },
TraceEvent::Entered { state: SR },
TraceEvent::EnterBegan { state: SA },
entry(SA, A_A_IN),
TraceEvent::Entered { state: SB },
TraceEvent::Entered { state: SA },
TraceEvent::EnterBegan { state: SB },
entry(SB, A_B_IN),
TraceEvent::Entered { state: SC },
TraceEvent::Entered { state: SB },
TraceEvent::EnterBegan { state: SC },
entry(SC, A_C_IN),
TraceEvent::Entered { state: SD },
TraceEvent::Entered { state: SC },
TraceEvent::EnterBegan { state: SD },
entry(SD, A_D_IN),
TraceEvent::Entered { state: SD },
// Halt.
TraceEvent::EventReceived { event: E_HALT },
TraceEvent::TerminateRequested { event: E_HALT },
// Bottom-up exit chain.
TraceEvent::ExitBegan { state: SD },
exit_(SD, A_D_OUT),
TraceEvent::Exited { state: SD },
TraceEvent::ExitBegan { state: SC },
exit_(SC, A_C_OUT),
TraceEvent::Exited { state: SC },
TraceEvent::ExitBegan { state: SB },
exit_(SB, A_B_OUT),
TraceEvent::Exited { state: SB },
TraceEvent::ExitBegan { state: SA },
exit_(SA, A_A_OUT),
TraceEvent::Exited { state: SA },
TraceEvent::ExitBegan { state: SR },
exit_(SR, A_R_OUT),
TraceEvent::Exited { state: SR },
TraceEvent::Terminated,
+73 -12
View File
@@ -11,7 +11,7 @@
#![cfg(all(feature = "tokio", feature = "journal"))]
#![allow(unexpected_cfgs)]
use hsmc::{statechart, ActionKind, TraceEvent};
use hsmc::{statechart, ActionKind, TraceEvent, TransitionReason};
#[derive(Default)]
pub struct Ctx;
@@ -146,11 +146,14 @@ fn initial_descent() -> Vec<TraceEvent> {
TraceEvent::Started {
chart_hash: Lat::<8>::CHART_HASH,
},
TraceEvent::EnterBegan { state: SR },
TraceEvent::Entered { state: SR },
TraceEvent::Entered { state: SP },
TraceEvent::EnterBegan { state: SP },
entry(SP, A_P_IN),
TraceEvent::Entered { state: SA },
TraceEvent::Entered { state: SP },
TraceEvent::EnterBegan { state: SA },
entry(SA, A_A_IN),
TraceEvent::Entered { state: SA },
]
}
@@ -185,6 +188,7 @@ async fn det_lateral_a_to_b_lca_is_parent() {
let mut expected = initial_descent();
expected.extend(vec![
TraceEvent::EventReceived { event: E_GOB },
TraceEvent::EventDelivered {
handler_state: SA,
event: E_GOB,
@@ -192,11 +196,18 @@ async fn det_lateral_a_to_b_lca_is_parent() {
TraceEvent::TransitionFired {
from: Some(SA),
to: SB,
reason: TransitionReason::Event { event: E_GOB },
},
TraceEvent::ExitBegan { state: SA },
exit_(SA, A_A_OUT),
TraceEvent::Exited { state: SA },
TraceEvent::Entered { state: SB },
TraceEvent::EnterBegan { state: SB },
entry(SB, A_B_IN),
TraceEvent::Entered { state: SB },
TraceEvent::TransitionComplete {
from: Some(SA),
to: SB,
},
]);
assert_journal(&actual, &expected);
})
@@ -215,6 +226,7 @@ async fn det_lateral_a_to_c_exits_parent() {
let mut expected = initial_descent();
expected.extend(vec![
TraceEvent::EventReceived { event: E_GOC },
TraceEvent::EventDelivered {
handler_state: SA,
event: E_GOC,
@@ -222,13 +234,21 @@ async fn det_lateral_a_to_c_exits_parent() {
TraceEvent::TransitionFired {
from: Some(SA),
to: SC,
reason: TransitionReason::Event { event: E_GOC },
},
TraceEvent::ExitBegan { state: SA },
exit_(SA, A_A_OUT),
TraceEvent::Exited { state: SA },
TraceEvent::ExitBegan { state: SP },
exit_(SP, A_P_OUT),
TraceEvent::Exited { state: SP },
TraceEvent::Entered { state: SC },
TraceEvent::EnterBegan { state: SC },
entry(SC, A_C_IN),
TraceEvent::Entered { state: SC },
TraceEvent::TransitionComplete {
from: Some(SA),
to: SC,
},
]);
assert_journal(&actual, &expected);
})
@@ -246,6 +266,7 @@ async fn det_lateral_target_with_children_default_descends() {
let mut expected = initial_descent();
expected.extend(vec![
TraceEvent::EventReceived { event: E_GOD },
TraceEvent::EventDelivered {
handler_state: SA,
event: E_GOD,
@@ -253,15 +274,24 @@ async fn det_lateral_target_with_children_default_descends() {
TraceEvent::TransitionFired {
from: Some(SA),
to: SD,
reason: TransitionReason::Event { event: E_GOD },
},
TraceEvent::ExitBegan { state: SA },
exit_(SA, A_A_OUT),
TraceEvent::Exited { state: SA },
TraceEvent::ExitBegan { state: SP },
exit_(SP, A_P_OUT),
TraceEvent::Exited { state: SP },
TraceEvent::Entered { state: SD },
TraceEvent::EnterBegan { state: SD },
entry(SD, A_D_IN),
TraceEvent::Entered { state: SE },
TraceEvent::Entered { state: SD },
TraceEvent::EnterBegan { state: SE },
entry(SE, A_E_IN),
TraceEvent::Entered { state: SE },
TraceEvent::TransitionComplete {
from: Some(SA),
to: SD,
},
]);
assert_journal(&actual, &expected);
})
@@ -280,6 +310,7 @@ async fn det_lateral_to_deeply_nested_target() {
let mut expected = initial_descent();
expected.extend(vec![
TraceEvent::EventReceived { event: E_GOE },
TraceEvent::EventDelivered {
handler_state: SA,
event: E_GOE,
@@ -287,15 +318,24 @@ async fn det_lateral_to_deeply_nested_target() {
TraceEvent::TransitionFired {
from: Some(SA),
to: SE,
reason: TransitionReason::Event { event: E_GOE },
},
TraceEvent::ExitBegan { state: SA },
exit_(SA, A_A_OUT),
TraceEvent::Exited { state: SA },
TraceEvent::ExitBegan { state: SP },
exit_(SP, A_P_OUT),
TraceEvent::Exited { state: SP },
TraceEvent::Entered { state: SD },
TraceEvent::EnterBegan { state: SD },
entry(SD, A_D_IN),
TraceEvent::Entered { state: SE },
TraceEvent::Entered { state: SD },
TraceEvent::EnterBegan { state: SE },
entry(SE, A_E_IN),
TraceEvent::Entered { state: SE },
TraceEvent::TransitionComplete {
from: Some(SA),
to: SE,
},
]);
assert_journal(&actual, &expected);
})
@@ -316,6 +356,7 @@ async fn det_lateral_chained_transitions() {
let mut expected = initial_descent();
// A → B
expected.extend(vec![
TraceEvent::EventReceived { event: E_GOB },
TraceEvent::EventDelivered {
handler_state: SA,
event: E_GOB,
@@ -323,14 +364,22 @@ async fn det_lateral_chained_transitions() {
TraceEvent::TransitionFired {
from: Some(SA),
to: SB,
reason: TransitionReason::Event { event: E_GOB },
},
TraceEvent::ExitBegan { state: SA },
exit_(SA, A_A_OUT),
TraceEvent::Exited { state: SA },
TraceEvent::Entered { state: SB },
TraceEvent::EnterBegan { state: SB },
entry(SB, A_B_IN),
TraceEvent::Entered { state: SB },
TraceEvent::TransitionComplete {
from: Some(SA),
to: SB,
},
]);
// B → C (LCA = Root, so Parent exits too).
expected.extend(vec![
TraceEvent::EventReceived { event: E_GOC },
TraceEvent::EventDelivered {
handler_state: SB,
event: E_GOC,
@@ -338,13 +387,21 @@ async fn det_lateral_chained_transitions() {
TraceEvent::TransitionFired {
from: Some(SB),
to: SC,
reason: TransitionReason::Event { event: E_GOC },
},
TraceEvent::ExitBegan { state: SB },
exit_(SB, A_B_OUT),
TraceEvent::Exited { state: SB },
TraceEvent::ExitBegan { state: SP },
exit_(SP, A_P_OUT),
TraceEvent::Exited { state: SP },
TraceEvent::Entered { state: SC },
TraceEvent::EnterBegan { state: SC },
entry(SC, A_C_IN),
TraceEvent::Entered { state: SC },
TraceEvent::TransitionComplete {
from: Some(SB),
to: SC,
},
]);
assert_journal(&actual, &expected);
})
@@ -360,9 +417,13 @@ async fn det_lateral_lca_stays_active() {
let _ = m.dispatch(Ev::GoB).await;
let j = m.take_journal();
// After initial Entered(Parent), Parent must not appear again.
let initial_p_idx = j
.iter()
.position(|e| matches!(e, TraceEvent::Entered { state: SP }))
.unwrap();
let parent_events: Vec<&TraceEvent> = j
.iter()
.skip(3)
.skip(initial_p_idx + 1)
.filter(|e| {
matches!(
e,
+15 -4
View File
@@ -17,7 +17,7 @@
#![cfg(all(feature = "tokio", feature = "journal"))]
#![allow(unexpected_cfgs)]
use hsmc::{statechart, ActionKind, TraceEvent};
use hsmc::{statechart, ActionKind, TraceEvent, TransitionReason};
#[derive(Default)]
pub struct Ctx;
@@ -101,12 +101,16 @@ async fn det_root_targetable_by_chart_name() {
TraceEvent::Started {
chart_hash: Sub::<8>::CHART_HASH,
},
TraceEvent::Entered { state: SR },
TraceEvent::EnterBegan { state: SR },
entry(SR, A_R_IN),
TraceEvent::Entered { state: SA },
TraceEvent::Entered { state: SR },
TraceEvent::EnterBegan { state: SA },
entry(SA, A_A_IN),
TraceEvent::Entered { state: SB },
TraceEvent::Entered { state: SA },
TraceEvent::EnterBegan { state: SB },
entry(SB, A_B_IN),
TraceEvent::Entered { state: SB },
TraceEvent::EventReceived { event: E_UPTOROOT },
TraceEvent::EventDelivered {
handler_state: SB,
event: E_UPTOROOT,
@@ -114,11 +118,18 @@ async fn det_root_targetable_by_chart_name() {
TraceEvent::TransitionFired {
from: Some(SB),
to: SR,
reason: TransitionReason::Event { event: E_UPTOROOT },
},
TraceEvent::ExitBegan { state: SB },
exit_(SB, A_B_OUT),
TraceEvent::Exited { state: SB },
TraceEvent::ExitBegan { state: SA },
exit_(SA, A_A_OUT),
TraceEvent::Exited { state: SA },
TraceEvent::TransitionComplete {
from: Some(SB),
to: SR,
},
];
assert_eq!(
+24 -5
View File
@@ -13,7 +13,7 @@
#![cfg(all(feature = "tokio", feature = "journal"))]
#![allow(unexpected_cfgs)]
use hsmc::{statechart, ActionKind, TraceEvent};
use hsmc::{statechart, ActionKind, TraceEvent, TransitionReason};
#[derive(Default)]
pub struct Ctx;
@@ -86,11 +86,14 @@ fn initial_descent() -> Vec<TraceEvent> {
TraceEvent::Started {
chart_hash: Self_::<8>::CHART_HASH,
},
TraceEvent::EnterBegan { state: SR },
TraceEvent::Entered { state: SR },
TraceEvent::Entered { state: SM },
TraceEvent::EnterBegan { state: SM },
entry(SM, A_M_IN),
TraceEvent::Entered { state: SL },
TraceEvent::Entered { state: SM },
TraceEvent::EnterBegan { state: SL },
entry(SL, A_L_IN),
TraceEvent::Entered { state: SL },
]
}
fn assert_journal(actual: &[TraceEvent], expected: &[TraceEvent]) {
@@ -123,6 +126,7 @@ async fn det_self_leaf_exits_and_reenters_only_leaf() {
let mut expected = initial_descent();
expected.extend(vec![
TraceEvent::EventReceived { event: E_SELFLEAF },
TraceEvent::EventDelivered {
handler_state: SL,
event: E_SELFLEAF,
@@ -130,11 +134,18 @@ async fn det_self_leaf_exits_and_reenters_only_leaf() {
TraceEvent::TransitionFired {
from: Some(SL),
to: SL,
reason: TransitionReason::Event { event: E_SELFLEAF },
},
TraceEvent::ExitBegan { state: SL },
exit_(SL, A_L_OUT),
TraceEvent::Exited { state: SL },
TraceEvent::Entered { state: SL },
TraceEvent::EnterBegan { state: SL },
entry(SL, A_L_IN),
TraceEvent::Entered { state: SL },
TraceEvent::TransitionComplete {
from: Some(SL),
to: SL,
},
]);
assert_journal(&actual, &expected);
})
@@ -209,6 +220,7 @@ async fn det_self_composite_default_descends() {
// Mid's entry actions don't fire. No default-descent.
let mut expected = initial_descent();
expected.extend(vec![
TraceEvent::EventReceived { event: E_SELFMID },
TraceEvent::EventDelivered {
handler_state: SM,
event: E_SELFMID,
@@ -216,9 +228,15 @@ async fn det_self_composite_default_descends() {
TraceEvent::TransitionFired {
from: Some(SL),
to: SM,
reason: TransitionReason::Event { event: E_SELFMID },
},
TraceEvent::ExitBegan { state: SL },
exit_(SL, A_L_OUT),
TraceEvent::Exited { state: SL },
TraceEvent::TransitionComplete {
from: Some(SL),
to: SM,
},
]);
assert_journal(&actual, &expected);
})
@@ -257,7 +275,8 @@ async fn det_self_leaf_repeated_is_deterministic() {
e,
TraceEvent::TransitionFired {
from: Some(SL),
to: SL
to: SL,
..
}
)
})
+4 -2
View File
@@ -85,7 +85,8 @@ async fn det_self_composite_default_descends_after_re_entry() {
e,
TraceEvent::TransitionFired {
from: Some(SP),
to: SP
to: SP,
..
}
)
})
@@ -133,7 +134,8 @@ async fn det_self_composite_action_kinds_in_order() {
e,
TraceEvent::TransitionFired {
from: Some(SP),
to: SP
to: SP,
..
}
)
})
+35 -6
View File
@@ -15,7 +15,7 @@
#![cfg(all(feature = "tokio", feature = "journal"))]
#![allow(unexpected_cfgs)]
use hsmc::{statechart, ActionKind, TraceEvent};
use hsmc::{statechart, ActionKind, TraceEvent, TransitionReason};
#[derive(Default)]
pub struct Ctx;
@@ -117,16 +117,21 @@ fn initial_descent() -> Vec<TraceEvent> {
TraceEvent::Started {
chart_hash: Up::<8>::CHART_HASH,
},
TraceEvent::Entered { state: SR },
TraceEvent::EnterBegan { state: SR },
entry(SR, A_R_IN),
TraceEvent::Entered { state: SA },
TraceEvent::Entered { state: SR },
TraceEvent::EnterBegan { state: SA },
entry(SA, A_A_IN),
TraceEvent::Entered { state: SB },
TraceEvent::Entered { state: SA },
TraceEvent::EnterBegan { state: SB },
entry(SB, A_B_IN),
TraceEvent::Entered { state: SC },
TraceEvent::Entered { state: SB },
TraceEvent::EnterBegan { state: SC },
entry(SC, A_C_IN),
TraceEvent::Entered { state: SD },
TraceEvent::Entered { state: SC },
TraceEvent::EnterBegan { state: SD },
entry(SD, A_D_IN),
TraceEvent::Entered { state: SD },
]
}
fn assert_journal(actual: &[TraceEvent], expected: &[TraceEvent]) {
@@ -159,6 +164,7 @@ async fn det_up_to_immediate_grandparent() {
let mut expected = initial_descent();
expected.extend(vec![
TraceEvent::EventReceived { event: E_UPTOC },
TraceEvent::EventDelivered {
handler_state: SD,
event: E_UPTOC,
@@ -166,9 +172,15 @@ async fn det_up_to_immediate_grandparent() {
TraceEvent::TransitionFired {
from: Some(SD),
to: SC,
reason: TransitionReason::Event { event: E_UPTOC },
},
TraceEvent::ExitBegan { state: SD },
exit_(SD, A_D_OUT),
TraceEvent::Exited { state: SD },
TraceEvent::TransitionComplete {
from: Some(SD),
to: SC,
},
]);
assert_journal(&actual, &expected);
})
@@ -186,6 +198,7 @@ async fn det_up_two_levels() {
let mut expected = initial_descent();
expected.extend(vec![
TraceEvent::EventReceived { event: E_UPTOB },
TraceEvent::EventDelivered {
handler_state: SD,
event: E_UPTOB,
@@ -193,11 +206,18 @@ async fn det_up_two_levels() {
TraceEvent::TransitionFired {
from: Some(SD),
to: SB,
reason: TransitionReason::Event { event: E_UPTOB },
},
TraceEvent::ExitBegan { state: SD },
exit_(SD, A_D_OUT),
TraceEvent::Exited { state: SD },
TraceEvent::ExitBegan { state: SC },
exit_(SC, A_C_OUT),
TraceEvent::Exited { state: SC },
TraceEvent::TransitionComplete {
from: Some(SD),
to: SB,
},
]);
assert_journal(&actual, &expected);
})
@@ -215,6 +235,7 @@ async fn det_up_three_levels_to_a() {
let mut expected = initial_descent();
expected.extend(vec![
TraceEvent::EventReceived { event: E_UPTOA },
TraceEvent::EventDelivered {
handler_state: SD,
event: E_UPTOA,
@@ -222,13 +243,21 @@ async fn det_up_three_levels_to_a() {
TraceEvent::TransitionFired {
from: Some(SD),
to: SA,
reason: TransitionReason::Event { event: E_UPTOA },
},
TraceEvent::ExitBegan { state: SD },
exit_(SD, A_D_OUT),
TraceEvent::Exited { state: SD },
TraceEvent::ExitBegan { state: SC },
exit_(SC, A_C_OUT),
TraceEvent::Exited { state: SC },
TraceEvent::ExitBegan { state: SB },
exit_(SB, A_B_OUT),
TraceEvent::Exited { state: SB },
TraceEvent::TransitionComplete {
from: Some(SD),
to: SA,
},
]);
assert_journal(&actual, &expected);
})
+20 -5
View File
@@ -12,7 +12,7 @@
#![cfg(all(feature = "tokio", feature = "journal"))]
#![allow(unexpected_cfgs)]
use hsmc::{statechart, ActionKind, TraceEvent};
use hsmc::{statechart, ActionKind, TraceEvent, TransitionReason};
#[derive(Default)]
pub struct Ctx;
@@ -97,19 +97,22 @@ async fn replay_full_lifecycle_matches_expected() {
TraceEvent::Started {
chart_hash: Replay::<8>::CHART_HASH,
},
TraceEvent::Entered { state: ST_ROOT },
TraceEvent::EnterBegan { state: ST_ROOT },
TraceEvent::ActionInvoked {
state: ST_ROOT,
action: A_ROOT_IN,
kind: ActionKind::Entry,
},
TraceEvent::Entered { state: ST_IDLE },
TraceEvent::Entered { state: ST_ROOT },
TraceEvent::EnterBegan { state: ST_IDLE },
TraceEvent::ActionInvoked {
state: ST_IDLE,
action: A_IDLE_IN,
kind: ActionKind::Entry,
},
TraceEvent::Entered { state: ST_IDLE },
// ── Go event delivered to Idle, transition to Active → Sub ──
TraceEvent::EventReceived { event: E_GO },
TraceEvent::EventDelivered {
handler_state: ST_IDLE,
event: E_GO,
@@ -117,39 +120,51 @@ async fn replay_full_lifecycle_matches_expected() {
TraceEvent::TransitionFired {
from: Some(ST_IDLE),
to: ST_ACTIVE,
reason: TransitionReason::Event { event: E_GO },
},
TraceEvent::ExitBegan { state: ST_IDLE },
TraceEvent::ActionInvoked {
state: ST_IDLE,
action: A_IDLE_OUT,
kind: ActionKind::Exit,
},
TraceEvent::Exited { state: ST_IDLE },
TraceEvent::Entered { state: ST_ACTIVE },
TraceEvent::EnterBegan { state: ST_ACTIVE },
TraceEvent::ActionInvoked {
state: ST_ACTIVE,
action: A_ACTIVE_IN,
kind: ActionKind::Entry,
},
TraceEvent::Entered { state: ST_SUB },
TraceEvent::Entered { state: ST_ACTIVE },
TraceEvent::EnterBegan { state: ST_SUB },
TraceEvent::ActionInvoked {
state: ST_SUB,
action: A_SUB_IN,
kind: ActionKind::Entry,
},
TraceEvent::Entered { state: ST_SUB },
TraceEvent::TransitionComplete {
from: Some(ST_IDLE),
to: ST_ACTIVE,
},
// ── Halt event triggers termination: exit Sub → Active → root, then Terminated ──
TraceEvent::EventReceived { event: E_HALT },
TraceEvent::TerminateRequested { event: E_HALT },
TraceEvent::ExitBegan { state: ST_SUB },
TraceEvent::ActionInvoked {
state: ST_SUB,
action: A_SUB_OUT,
kind: ActionKind::Exit,
},
TraceEvent::Exited { state: ST_SUB },
TraceEvent::ExitBegan { state: ST_ACTIVE },
TraceEvent::ActionInvoked {
state: ST_ACTIVE,
action: A_ACTIVE_OUT,
kind: ActionKind::Exit,
},
TraceEvent::Exited { state: ST_ACTIVE },
TraceEvent::ExitBegan { state: ST_ROOT },
TraceEvent::ActionInvoked {
state: ST_ROOT,
action: A_ROOT_OUT,
+429
View File
@@ -0,0 +1,429 @@
//! Verifies the textual format of the unified observation pipeline's
//! `trace-log` sink line-for-line.
//!
//! Each `__chart_observe!` arm has a stable logfmt-style format:
//!
//! `[statechart:<Name>] <verb> key=value key=value …`
//!
//! These tests pin every verb's exact rendering so a real-life log capture
//! can be diffed against expected behavior. The chart is exercised through
//! both the journal sink (so we can assert atom-by-atom equivalence) and
//! the trace-log sink (so we can assert the rendered strings).
#![cfg(all(feature = "tokio", feature = "journal", feature = "trace-log"))]
#![allow(unexpected_cfgs)]
use hsmc::{statechart, Duration, TraceEvent, TransitionReason};
use std::sync::{Mutex, MutexGuard, OnceLock};
// ── Capture sink ─────────────────────────────────────────────────────
//
// log::set_logger can only be installed once per process. The capture
// holds a single Vec<String> shared across all tests, plus a global
// `TEST_LOCK` that each test holds across its drive-then-assert
// section so concurrent tests don't interleave their captured lines.
struct Capture {
lines: Mutex<Vec<String>>,
}
impl log::Log for Capture {
fn enabled(&self, _: &log::Metadata<'_>) -> bool {
true
}
fn log(&self, record: &log::Record<'_>) {
if let Ok(mut g) = self.lines.lock() {
g.push(format!("{}", record.args()));
}
}
fn flush(&self) {}
}
static CAPTURE: OnceLock<&'static Capture> = OnceLock::new();
static TEST_LOCK: Mutex<()> = Mutex::new(());
fn install_capture() -> &'static Capture {
*CAPTURE.get_or_init(|| {
let leaked: &'static Capture = Box::leak(Box::new(Capture {
lines: Mutex::new(Vec::new()),
}));
let _ = log::set_logger(leaked);
log::set_max_level(log::LevelFilter::Trace);
leaked
})
}
/// RAII helper. Acquire before driving the chart, drop after assertions
/// — keeps `tests::*` from interleaving captured log lines.
fn lock_for_test() -> MutexGuard<'static, ()> {
install_capture();
let g = TEST_LOCK.lock().unwrap_or_else(|p| p.into_inner());
// Clear any lines left by a previous test that paniced before
// draining (poison case).
let cap = CAPTURE.get().unwrap();
cap.lines.lock().unwrap().clear();
g
}
fn current_lines() -> Vec<String> {
let cap = install_capture();
cap.lines.lock().unwrap().clone()
}
// ── Test chart ───────────────────────────────────────────────────────
//
// Covers every observation verb the macro can emit. Two states with
// entry/exit actions, a handler that emits and transitions, a timer,
// a during, and a terminate event.
#[derive(Default)]
pub struct Ctx {
pub buf: u32,
}
#[derive(Debug, Clone)]
pub enum Ev {
Go,
Step,
Halt,
}
statechart! {
TraceFmt {
context: Ctx;
events: Ev;
default(Idle);
terminate(Halt);
state Idle {
entry: idle_in;
exit: idle_out;
during: tick(buf);
on(after Duration::from_secs(60)) => Idle;
on(Go) => Active;
}
state Active {
entry: active_in;
exit: active_out;
on(Step) => bump;
on(Halt) => Idle;
}
}
}
async fn tick(_buf: &mut u32) -> Ev {
Ev::Step
}
impl TraceFmtActions for TraceFmtActionContext<'_> {
async fn idle_in(&mut self) {}
async fn idle_out(&mut self) {}
async fn active_in(&mut self) {}
async fn active_out(&mut self) {}
async fn bump(&mut self) {
let _ = self.emit(Ev::Halt);
}
}
// ── Helpers ──────────────────────────────────────────────────────────
/// Returns true iff `line` matches the expected `[statechart:TraceFmt] verb …`
/// shape. Every line emitted by the dispatcher must.
fn well_formed(line: &str) -> bool {
line.starts_with("[statechart:TraceFmt] ")
}
/// Filter `lines` to only those whose verb (the first token after the
/// prefix) equals `verb`. Useful for asserting on a single verb's lines.
fn lines_with_verb<'a>(lines: &'a [String], verb: &str) -> Vec<&'a str> {
let prefix = "[statechart:TraceFmt] ";
lines
.iter()
.filter_map(|l| l.strip_prefix(prefix))
.filter(|rest| rest.split_whitespace().next() == Some(verb))
.map(|s| s.as_ref())
.collect()
}
// ── Tests ────────────────────────────────────────────────────────────
#[tokio::test(flavor = "current_thread")]
async fn every_line_uses_statechart_prefix() {
let _g = lock_for_test();
tokio::task::LocalSet::new()
.run_until(async {
let mut m = TraceFmt::new(Ctx::default());
let _ = m.dispatch(Ev::Go).await;
let _ = m.dispatch(Ev::Halt).await;
})
.await;
let lines = current_lines();
assert!(!lines.is_empty(), "no log lines captured");
for l in &lines {
assert!(
well_formed(l),
"line missing [statechart:TraceFmt] prefix: {l:?}"
);
}
}
#[tokio::test(flavor = "current_thread")]
async fn enter_and_exit_emit_begin_end_pairs() {
let _g = lock_for_test();
tokio::task::LocalSet::new()
.run_until(async {
let mut m = TraceFmt::new(Ctx::default());
let _ = m.dispatch(Ev::Go).await;
})
.await;
let lines = current_lines();
let entering = lines_with_verb(&lines, "entering");
let entered = lines_with_verb(&lines, "entered");
assert_eq!(
entering.len(),
entered.len(),
"every `entering` must have a matching `entered`"
);
assert!(entering.contains(&"entering state=TraceFmt"));
assert!(entered.contains(&"entered state=TraceFmt"));
assert!(entering.contains(&"entering state=Idle"));
assert!(entered.contains(&"entered state=Idle"));
}
#[tokio::test(flavor = "current_thread")]
async fn transition_records_event_reason() {
let _g = lock_for_test();
tokio::task::LocalSet::new()
.run_until(async {
let mut m = TraceFmt::new(Ctx::default());
let _ = m.dispatch(Ev::Go).await;
})
.await;
let lines = current_lines();
let begins = lines_with_verb(&lines, "transition-begin");
assert!(!begins.is_empty(), "no transition-begin lines captured");
let line = begins[0];
assert!(
line.contains("from=Idle"),
"transition-begin missing from=Idle: {line:?}"
);
assert!(
line.contains("to=Active"),
"transition-begin missing to=Active: {line:?}"
);
assert!(
line.contains("reason=event:Go"),
"transition-begin missing reason=event:Go: {line:?}"
);
let completes = lines_with_verb(&lines, "transition-complete");
assert!(
!completes.is_empty(),
"transition-complete must follow transition-begin"
);
assert!(completes[0].contains("from=Idle") && completes[0].contains("to=Active"));
}
#[tokio::test(flavor = "current_thread")]
async fn event_lifecycle_received_then_outcome() {
let _g = lock_for_test();
tokio::task::LocalSet::new()
.run_until(async {
let mut m = TraceFmt::new(Ctx::default());
let _ = m.dispatch(Ev::Go).await;
})
.await;
let lines = current_lines();
let received = lines_with_verb(&lines, "event-received");
let delivered = lines_with_verb(&lines, "event-delivered");
assert!(received.iter().any(|l| l.contains("name=Go")));
assert!(delivered
.iter()
.any(|l| l.contains("name=Go") && l.contains("handler=Idle")));
}
#[tokio::test(flavor = "current_thread")]
async fn during_emits_started_and_cancelled() {
let _g = lock_for_test();
tokio::task::LocalSet::new()
.run_until(async {
let mut m = TraceFmt::new(Ctx::default());
// Go enters Active, which causes Idle's during to be cancelled.
let _ = m.dispatch(Ev::Go).await;
})
.await;
let lines = current_lines();
let started = lines_with_verb(&lines, "during-started");
let cancelled = lines_with_verb(&lines, "during-cancelled");
assert!(started.iter().any(|l| l.contains("during=tick")));
assert!(cancelled.iter().any(|l| l.contains("during=tick")));
}
#[tokio::test(flavor = "current_thread")]
async fn timer_arm_then_cancel_lines() {
let _g = lock_for_test();
tokio::task::LocalSet::new()
.run_until(async {
let mut m = TraceFmt::new(Ctx::default());
let _ = m.dispatch(Ev::Go).await;
})
.await;
let lines = current_lines();
let armed = lines_with_verb(&lines, "timer-armed");
let cancelled = lines_with_verb(&lines, "timer-cancelled");
assert!(
armed.iter().any(|l| l.contains("state=Idle")),
"timer should arm when Idle is entered"
);
assert!(
cancelled.iter().any(|l| l.contains("state=Idle")),
"timer should be cancelled when Idle is exited (Go transition)"
);
}
#[tokio::test(flavor = "current_thread")]
async fn emit_queued_appears_for_handler_emit() {
let _g = lock_for_test();
tokio::task::LocalSet::new()
.run_until(async {
let mut m = TraceFmt::new(Ctx::default());
let _ = m.dispatch(Ev::Go).await;
// Step's handler calls emit(Halt).
let _ = m.dispatch(Ev::Step).await;
})
.await;
let lines = current_lines();
let queued = lines_with_verb(&lines, "emit-queued");
assert!(
queued.iter().any(|l| l.contains("event=Halt")),
"expected emit-queued event=Halt line: {lines:?}"
);
}
#[tokio::test(flavor = "current_thread")]
async fn terminate_records_request_then_terminated() {
let _g = lock_for_test();
tokio::task::LocalSet::new()
.run_until(async {
let mut m = TraceFmt::new(Ctx::default());
let _ = m.dispatch(Ev::Go).await;
// Halt from Active is a transition to Idle (no terminate);
// dispatch Halt twice via Idle to actually terminate.
// First Go landed us in Active; Halt → Idle (handler).
let _ = m.dispatch(Ev::Halt).await; // back to Idle
let _ = m.dispatch(Ev::Halt).await; // now terminate
})
.await;
let lines = current_lines();
let req = lines_with_verb(&lines, "terminate-requested");
let term = lines_with_verb(&lines, "terminated");
assert!(
req.iter().any(|l| l.contains("event=Halt")),
"expected terminate-requested event=Halt: {lines:?}"
);
assert!(
!term.is_empty(),
"expected a final `terminated` line: {lines:?}"
);
}
#[tokio::test(flavor = "current_thread")]
async fn started_records_chart_hash() {
let _g = lock_for_test();
tokio::task::LocalSet::new()
.run_until(async {
let mut m = TraceFmt::new(Ctx::default());
let _ = m.dispatch(Ev::Go).await;
})
.await;
let lines = current_lines();
let started = lines_with_verb(&lines, "started");
assert!(!started.is_empty(), "expected one `started` line");
assert!(
started[0].contains("chart_hash=0x"),
"started must include chart_hash in hex: {:?}",
started[0]
);
}
#[tokio::test(flavor = "current_thread")]
async fn trace_and_journal_have_matching_atom_count() {
// The "one journal, multiple outputs" contract: every TraceEvent
// recorded in the journal corresponds to exactly one log line in
// the trace, modulo verb-name differences.
let _g = lock_for_test();
let actual = tokio::task::LocalSet::new()
.run_until(async {
let mut m = TraceFmt::new(Ctx::default());
let _ = m.dispatch(Ev::Go).await;
m.take_journal()
})
.await;
let lines = current_lines();
assert_eq!(
actual.len(),
lines.len(),
"journal/trace atom count diverged ({} vs {} lines)",
actual.len(),
lines.len()
);
}
#[tokio::test(flavor = "current_thread")]
async fn transition_reason_in_journal_matches_trace() {
// The journal records the structured `TransitionReason::Event { event }`
// and the trace renders it as `event:<VariantName>`. They must agree.
let _g = lock_for_test();
let actual = tokio::task::LocalSet::new()
.run_until(async {
let mut m = TraceFmt::new(Ctx::default());
let _ = m.dispatch(Ev::Go).await;
m.take_journal()
})
.await;
let lines = current_lines();
let journal_reason = actual.iter().find_map(|e| match e {
TraceEvent::TransitionFired { reason, .. } => Some(*reason),
_ => None,
});
let trace_reason_line = lines_with_verb(&lines, "transition-begin")
.first()
.copied()
.map(|s| s.to_string());
assert_eq!(
journal_reason,
Some(TransitionReason::Event { event: 0 }),
"expected first transition driven by Ev::Go (event id 0)"
);
assert!(
trace_reason_line
.as_deref()
.is_some_and(|l| l.contains("reason=event:Go")),
"trace reason should match journal reason: {trace_reason_line:?}"
);
}