# Wait cycle blocks required producers

Rule ID: concurrency.sole-producer-self-block@1.0.0. Availability below refers to source-scan at product 524fa07e.

## V-ASYNC-15 — Wait cycle blocks required producers

Wait cycle blocks required producers. It examines task ordering, suspension, cancellation, progress, and async obligations.

### Availability

Not available in source-scan. There is no source-scan flag to activate this condition.

### Example and action

Illustrative design scenario, not a runnable Swift example or a reproduced analyzer result. The stated availability and evidence boundaries still apply.

**Before:** A task blocks a serial executor waiting for a callback that must run on that same executor.

Review the following change against the contract and build variants described above.

**After:** Replace the blocking wait with an asynchronous handoff that lets the executor run the producer. Reconstruct the whole wait cycle before changing queues; another dependency can preserve the deadlock.

### Intended analysis

Intended reasoning: Follow the relevant state, task or synchronization events across control-flow and suspension boundaries. The intended decision needs the complete event ordering and the operation contract; opaque events can leave the result unknown. Required evidence: task, suspension, cancellation, ordering, and progress facts

### Assumptions and unknown

The relevant facts must be admitted for the selected immutable build world. Unknown aliases, external effects, unsupported source forms or incomplete consumers can prevent a conclusion. Availability in this workflow is stated above; the illustration does not expand that availability.

### Evidence and interpretation

The target catalog describes the intended condition. It is not evidence of an active source-scan diagnostic.

Historical evidence at 4558458d: recovery-required (historical qualification is incomplete and needs further evidence). That evidence has not been requalified for this product revision.

[How we validate checks](https://docs.swift-analyzer.com/concepts/validation/) explains the evidence boundary. [Foundations](https://docs.swift-analyzer.com/concepts/foundations/) separates method assumptions from implementation claims.


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Language: en
Canonical: https://docs.swift-analyzer.com/catalog/concurrency.sole-producer-self-block/
Product revision: 524fa07e0ae4153c84ac12ae9eb6559df89ec2be
Catalog revision: 4558458d
Documentation digest: 1f17ba58ab08627e0de898f1442067b09e960b48cd5605d6529e9275f8930d68
Channel: pre-prod; maturity: experimental; access: owner-provided checkout.