Fix duplicate task generation (frontport of #5431)#5459
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The task processor can call `process_actions` multiple times while a previous batch's tasks are still in-flight. When there's a backlog (`schedule.start` far in the past), the deadline timer fires immediately because the next event is also in the past. The `last_requested_callbacks` guard passes, and `next_actions` reads stale on-chain state (schedule.start hasn't advanced yet), generating overlapping timestamps. When both batches are eventually submitted as blocks, batch 2's stale timestamps don't match the now-advanced `schedule.start`, causing: ``` contract.rs:115: assert_eq!(timed_data.timestamp, next_timestamp, "unexpected timestamp in posted data") ``` Introduce an `in_flight_apps: BTreeSet<ApplicationId>` guard in the task processor. When a batch of tasks is spawned for an application, the app is marked as in-flight and subsequent `process_actions` calls skip it. A new `TaskMessage` enum replaces the raw `(ApplicationId, TaskOutcome)` channel, adding a `BatchComplete` variant that the spawned task sends after all outcomes. On `BatchComplete`, the guard is cleared and `process_actions` is re-triggered for that app so it reads freshly-updated on-chain state. - CI - I had a stuck worker with a big backlog. After rebuilding pm-app with this fix and restarting the worker with the new package version, I see no more panics, and it seems that the worker is actually making progress through the backlog: 
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This was referenced Feb 17, 2026
ma2bd
approved these changes
Feb 17, 2026
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Motivation
Frontport of #5431 from
testnet_conwaytomain.Proposal
Cherry-pick of #5431 with conflict resolution (adapted
cursorsfield name used onmain).Test Plan
CI.