STATE-01 over the FLYSESS1 envelope CONTRACT-01 specified.
fly-session gains a `state` module: the durable store with its generations, its
rotation and the commit order of checkpoint-envelope-v1 section 5, where the store
manifest rename is the durable commit point; a compatibility block whose comparison
names the identity that differs rather than one opaque digest; and a bounded writer
that owns its payload handles until the bytes are committed or the job fails.
The writer's queue slot is taken before the first State.Capture, so a saturated
writer refuses a capture rather than queueing it without bound, and the refusal is a
BUSY the stepping session survives. Capture and durability are two events: a capture
completes when an immutable capture exists, and only the store manifest rename moves
the durable mark. A lost save reply is an outcome, and the resolution asks the store
about the same checkpoint instead of saving again.
Both worker roles implement State.Capture, State.StageRestore and
State.ActivateRestore, with once-only restore tokens bound to checkpoint, scope,
payload and incarnation. A restore selects a complete compatible generation, imports
every payload as a fresh artifact, stages the group, validates the coordinator's own
ledgers, and only then activates; a failure anywhere leaves the fence closed and
records every participant that staged as one that must be replaced. The fence lifts
at Failed -> Restoring(k) -> Paused(k) and nowhere else.
The task and the action executor gain the capture/validate_restore/install_restore
interfaces workers-v1 section 4 lists, and the ledger can re-derive the event
identities it issued under another epoch, which is what lets a resumed run's
behaviour trace be compared with an uninterrupted one.
media: check_required_audio now takes the observation's provenance instead of
exempting boundary 0. A chunk is the audio of an interval, and the observation
ActivateRestore installs covers none.
checkpoint-envelope-v1 section 3 gains a dated amendment adding `environment` to the
manifest, the holder of the world's own payload, which the table named for every
other participant; `helperState`, which that table already listed, joins the
required-field set in Rust and TypeScript. The fixture was regenerated by the
existing example; the schema set and contractDigest are unchanged.
state-media-v1 section 5 gains a dated amendment for three readings this slice
enforces: the State RPCs' compatibilityDigest is the participant's, not the
manifest's composition-level block; a restored observation carries no audio chunk;
and a participant that staged into an abandoned install must be replaced.
CONTRACT-01 landed its crate, so the local stand-in module goes away and the domain
scalars, method payloads, their validation, the canonical digests and the trace format
all come from the contract. `src/types.rs` is a facade over that crate plus the few
things a coordinator needs that are not part of the type contract: a session-side
DomainError, the synthetic composition's schema and event-id derivations, and the
coordinator-local ControllerIntent, PortBinding and AgentOutcome that never cross the
bus.
Consequences worth naming:
- Payloads are read and written through DomainType::from_json / to_json instead of
serde derives, so a misspelled required field fails where the contract says it
should. serde, sha2 and ryu-js leave this crate's dependencies with them.
- The step-v1 section 8 trace is the contract's TransitionTrace, with behaviour and
operational metadata already separated; the dispatch-order comparison now runs over
the contract's own behaviour encoding.
- Two things the migration found. IN_PROGRESS is raised strictly before any mutation,
so its certainty is "none", not "unknown"; the local module had it wrong.
WorldObservation::validate_against checks the views a result carries but does not
require every declared view to be present, so requiring them is made explicit in the
coordinator's phase C check, where step-v1 puts it.
- The lost-Advance-result injection now waits for the worker to report the operation
before abandoning the call, so the case it injects really is a loss after dispatch
rather than a cancellation before it.
Gates: cargo test -p fly-session (61 tests, both transports), cargo clippy
--all-targets clean, and the runnable example produces the same behaviour trace over
both transports.
The lockstep coordinator, its phase machine and a synthetic composition, as a new
workspace member. Every worker method is a Flybus RPC to an incarnation-pinned
service; the domain request ids and result caches of ipc-v1 section 5 sit in front of
every mutation.
- coordinator: the step-v1 section 3 transaction in order -- prepare every agent
concurrently, run one executor per agent in sorted agent-id order, assemble all port
controls in descriptor order, send exactly one Environment.Advance, evaluate the task
once, commit every agent concurrently, and move the committed boundary only when all
of them succeeded. Sequential, concurrent and reversed dispatch are selectable and
must agree.
- phase: the section 2 machine as an explicit edge table, Paused and Failed included,
with a committed-boundary predicate that gates pauses, captures and publication.
- clock: checked rational accumulation. A 60 Hz world with a 1 ms model tick runs
16, 17, 17 ticks and comes back to a remainder of exactly zero.
- dedup: operation keys, the cached reply with its own artifact holds, CONFLICT,
IN_PROGRESS, RESULT_EXPIRED, STALE_STEP, the lifecycle bound and Worker.Acknowledge.
- worker: the dispatch shell. Admission order and the result cache live here; the
endpoint mutex is the worker's simulation lock, so one mutation runs at a time while
Worker.Status answers from a separate cell.
- agent, environment, task: a fake model with an explicit seed and a mutation counter
the tests read, a fixed readout stub, a counter arena that seals one immutable frame
per boundary, a deterministic task and the identity executor.
- fly_session_types: the CONTRACT-01 domain types as a local stand-in, reconciled with
the shared crate in a following commit.
Tests run twice, over the in-memory transport and over a Unix socket, through the same
router: the SESSION-01 acceptance bullets and every section 4 failure-injection row
that applies to this slice.
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