feat: Allow external semaphore for executor busy state tracking - #14
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This change allows the semaphore controlling task concurrency to be passed into the poll_loop instead of being created internally. This enables: 1. Sharing the semaphore across multiple poll loops connected to different scheduler nodes 2. External tracking of executor busy state by querying available_permits() 3. Reporting busy state in scheduler shared state location metadata The semaphore parameter is optional - if None is passed, the function creates one internally to maintain backwards compatibility.
phillipleblanc
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Jan 29, 2026
This was referenced Jun 23, 2026
milenkovicm
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Jul 20, 2026
* feat: allow an external semaphore for executor task concurrency Adds an optional available_task_slots: Option<Arc<Semaphore>> parameter to the executor poll_loop. When provided, the caller supplies the semaphore that bounds concurrent task execution; this enables sharing it across poll loops connected to different schedulers and observing executor busy state via available_permits(). When None, the loop creates one internally sized to the executor's task slots (unchanged behavior). Ported from spiceai#14 for upstreaming. Note: layers on the poll_loop signature; if landed after #12 (poll_now_notify) it needs a trivial rebase to add both parameters. * fix(examples): pass optional semaphore arg in mtls-cluster and reformat standalone * fix(executor): address PR review feedback on shared-semaphore poll_loop - Handle AcquireError from semaphore acquire/acquire_owned by mapping to BallistaError instead of panicking, since the semaphore may now be externally owned and closed by the caller - Assert that the provided semaphore has at least one permit on entry to fail fast rather than deadlock - Rewrite poll_loop doc comment to be public-facing: remove references to internal variable names and implementation types, document shared- semaphore over-commit semantics and sizing tradeoffs in behavioral terms, and add a # Panics section for the zero-permit case * style: cargo fmt execution_loop.rs --------- Co-authored-by: Phillip LeBlanc <879445+phillipleblanc@users.noreply.github.com>
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This change allows the semaphore controlling task concurrency to be passed into the poll_loop instead of being created internally. This enables:
The semaphore parameter is optional - if None is passed, the function creates one internally to maintain backwards compatibility.