Sample
tower 0.5.3: Enforce Tower Service backpressure by pairing every call with a prior poll_ready, isolating Buffer permits from clones, and maintaining top-to-bottom ServiceBuilder layer ordering
Verified sample for cargo tower 0.5.3: Enforce Tower Service backpressure by pairing every call with a prior poll_ready, isolating Buffer permits from clones…
sha256:37636c110523173cb669e2b2a52feda3274b7cc8998bcb54c04b6b7a5c230bae
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
- Enforce Tower Service backpressure by pairing every call with a prior poll_ready, isolating Buffer permits from clones, and maintaining top-to-bottom ServiceBuilder layer ordering
- Packages
- Symbols
-
- tower::Service
- tower::ServiceExt
- tower::buffer::Buffer
- tower::limit::ConcurrencyLimit
- tower::ServiceBuilder
- Environment
- rust
- Created
- 2026-08-16T08:25:13Z
Contract
- ServiceExt::ready(&mut svc) acquires a single-use readiness permit consumed by the next call()
- Invoking call() on a Buffer or ConcurrencyLimit without poll_ready or after permit exhaustion panics at runtime
- Cloning a readied Buffer does not transfer the permit to the clone; calling call() on the clone panics
- Concurrent task dispatch requires cloning before ready/oneshot rather than cloning an already-readied instance
- ServiceBuilder layer order executes from top to bottom (outermost first) on requests
Files
- Cargo.lock
- Cargo.toml
- NOTES.md
- csx.json
- src/lib.rs
- tests/contract.rs