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fix(skippy): avoid duplicate lifecycle token handoff #1202

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Merged
i386 merged 2 commits into from
Aug 8, 2026
Merged

fix(skippy): avoid duplicate lifecycle token handoff #1202

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9548567
fix(skippy): avoid duplicate lifecycle token handoff
i386 Aug 8, 2026
c844e31
Merge branch 'main' into agent/upstream-proposal-state-handoff
i386 Aug 8, 2026
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161 changes: 154 additions & 7 deletions crates/mesh-native-serving-plugin-host/src/lib.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -469,13 +469,35 @@ impl ActivePlugin {
if !query.pending_token_ids.is_empty() {
let generated_token_count = query
.committed_token_count
.saturating_sub(query.prompt_token_count);
self.commit_tokens(
query.request_id,
query.session_id,
generated_token_count,
&query.pending_token_ids,
)?;
.checked_sub(query.prompt_token_count)
.context(
"native serving plugin proposal committed token count precedes prompt token count",
)?;
let key = (query.request_id, query.session_id);
let tracked_generated_token_count = self
.committed_generated_tokens
.lock()
.map_err(|_| anyhow!("native serving plugin commit state lock poisoned"))?
.get(&key)
.copied()
.context("native serving plugin proposal has no active generation state")?;
if generated_token_count < tracked_generated_token_count {
bail!("native serving plugin proposal rewound the tracked generated-token prefix");
}
if generated_token_count > tracked_generated_token_count {
let delta = generated_token_count - tracked_generated_token_count;
if delta != query.pending_token_ids.len() {
bail!(
"native serving plugin proposal pending-token count does not match the uncommitted suffix"
);
}
self.commit_tokens(
query.request_id,
query.session_id,
generated_token_count,
&query.pending_token_ids,
)?;
}
}
let event = abi::ProposalQuery {
struct_size: size_of::<abi::ProposalQuery>(),
Expand Down Expand Up @@ -895,4 +917,129 @@ mod tests {
.contains("table size")
);
}

#[test]
fn proposal_does_not_recommit_tokens_already_delivered_by_lifecycle() {
let (active, events) = test_support::fake_active_with_events(Duration::ZERO);
active
.begin(&GenerationStart {
request_id: 1,
session_id: 2,
agent_session_id: None,
prompt_token_ids: Arc::from([3]),
})
.unwrap();
active
.committed(&GenerationCommit {
request_id: 1,
session_id: 2,
generated_token_count: 1,
token_ids: vec![4].into_boxed_slice(),
})
.unwrap();

let result = active
.propose(
LinearProposalQuery::new(
1,
2,
1,
2,
1,
8,
Instant::now() + Duration::from_millis(100),
)
.with_pending_token_ids(vec![4].into_boxed_slice()),
)
.unwrap();

assert!(result.is_none());
assert_eq!(*events.lock().unwrap(), ["begin", "commit", "proposal"]);
}

#[test]
fn proposal_rejects_missing_generation_state() {
let (active, _) = test_support::fake_active_with_events(Duration::ZERO);
let error = active
.propose(
LinearProposalQuery::new(
1,
2,
1,
2,
1,
8,
Instant::now() + Duration::from_millis(100),
)
.with_pending_token_ids(vec![4].into_boxed_slice()),
)
.unwrap_err();
assert!(error.to_string().contains("no active generation state"));
}

#[test]
fn proposal_rejects_a_rewound_generation_prefix() {
let (active, _) = test_support::fake_active_with_events(Duration::ZERO);
active
.begin(&GenerationStart {
request_id: 1,
session_id: 2,
agent_session_id: None,
prompt_token_ids: Arc::from([3]),
})
.unwrap();
active
.committed(&GenerationCommit {
request_id: 1,
session_id: 2,
generated_token_count: 2,
token_ids: vec![4, 5].into_boxed_slice(),
})
.unwrap();

let error = active
.propose(
LinearProposalQuery::new(
1,
2,
1,
2,
1,
8,
Instant::now() + Duration::from_millis(100),
)
.with_pending_token_ids(vec![4].into_boxed_slice()),
)
.unwrap_err();
assert!(error.to_string().contains("rewound"));
}

#[test]
fn proposal_rejects_an_inconsistent_pending_suffix() {
let (active, _) = test_support::fake_active_with_events(Duration::ZERO);
active
.begin(&GenerationStart {
request_id: 1,
session_id: 2,
agent_session_id: None,
prompt_token_ids: Arc::from([3]),
})
.unwrap();

let error = active
.propose(
LinearProposalQuery::new(
1,
2,
1,
3,
1,
8,
Instant::now() + Duration::from_millis(100),
)
.with_pending_token_ids(vec![4].into_boxed_slice()),
)
.unwrap_err();
assert!(error.to_string().contains("pending-token count"));
}
}
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