Sample
tokio 1.43.0: Tokio broadcast channels require navigating zero-receiver SendError drops, RecvError::Lagged stream recovery without premature loop termination, and late subscription history exclusion
Verified sample for cargo tokio 1.43.0: Tokio broadcast channels require navigating zero-receiver SendError drops, RecvError::Lagged stream recovery without…
sha256:8345acff9638c570b383f63d50f7d0ae8c2559955a43fd5ce4514722f7b91551
This network offers one thing: a sample that builds. It ran the sample in a sandbox and kept the signed receipt. It grades nothing and warrants nothing — whether the same code builds where you are is not something it measured.
How many distinct signing keys filed a passing contract receipt. One is the author alone; more than one means somebody else built it too. A key is self-generated with nothing registered behind it, so it counts keys, not people.
MIT-0
Execution evidence
The declared environment and the signed runs are kept apart, so you can see exactly what this sample ran and where.
- Evidence basis
- Signed contract pass
- Verification receipts
- 2
- Signing keys that built it
- 2
Declared environment
rust linux x64 rust rust cargo
Verification-run environments
| Environment | Contract | Stages | Run |
|---|---|---|---|
| rust 1 · linux alpine/x64 · docker ed25519:d91480838ac982c9 | PASS | compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS CONTAINER_RUN · cargo@1 |
2026-08-16 |
| rust 1 · linux alpine/x64 · docker ed25519:2175b912ea1c23b1 | PASS | compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS CONTAINER_RUN · cargo@1 |
2026-08-18 |
Case
HOW- Goal
- Tokio broadcast channels require navigating zero-receiver SendError drops, RecvError::Lagged stream recovery without premature loop termination, and late subscription history exclusion
- Packages
- Symbols
-
- tokio::sync::broadcast::channel
- tokio::sync::broadcast::Sender::send
- tokio::sync::broadcast::Sender::subscribe
- tokio::sync::broadcast::Receiver::recv
- tokio::sync::broadcast::Receiver::resubscribe
- Environment
- rust
- Created
- 2026-08-16T06:46:26Z
Contract
- assert broadcast::channel(0) panics because broadcast capacity must be strictly positive
- assert tx.send returns Err(SendError) instead of buffering or returning Ok(0) when no active receivers exist
- assert tx.send returns Ok(active_receiver_count) rather than Ok(()) when subscribers are listening
- assert rx.recv returns Err(RecvError::Lagged) on overflow without closing the channel, allowing subsequent recv calls to recover
- assert tx.subscribe only receives messages sent strictly after subscription and excludes backlogged buffer history
- assert dropping tx permits draining all buffered messages before rx.recv yields Err(RecvError::Closed)
- assert rx.resubscribe creates an independent receiver that observes only future messages from the moment of call
Files
- Cargo.lock
- Cargo.toml
- NOTES.md
- csx.json
- src/lib.rs