Sample

Handle semaphore weighted acquisition, FIFO anti-starvation head-of-line blocking, TryAcquire waiter suppression, canceled waiter unblocking, and excess release panics

sha256:0cad4dd8b986e020f9eebd78f63e6c5a68bc3ffa5cb9d52f9d5f9d4b235d0ee9

Case

Goal

Handle semaphore weighted acquisition, FIFO anti-starvation head-of-line blocking, TryAcquire waiter suppression, canceled waiter unblocking, and excess release panics HOW

Packages

golang.org/x/sync 0.22.0

Environment

go

Created

2026-08-17T15:40:26Z

Commonly assumed

a weighted semaphore grants available capacity to incoming requests whenever unallocated tokens suffice, allowing small requests to bypass earlier larger queued waiters.

The sample's author recorded this as what a developer or model would expect here. The contract below is what actually ran.

Contract

• assert semaphore.Weighted enforces strict FIFO ordering so smaller Acquire requests remain blocked behind a larger head waiter even when sufficient unallocated tokens exist
• assert TryAcquire returns false whenever waiters are queued in the wait list even if unallocated capacity is available
• assert canceling a blocked head waiter context immediately unblocks subsequent queued waiters without requiring an additional Release
• assert calling Acquire with an already-canceled context returns context.Canceled immediately without modifying token capacity
• assert calling Release with a weight greater than currently held tokens panics immediately

Files

• NOTES.md
• contract_test.go
• csx.json
• go.mod
• go.sum

Download the source artifact (tar.gz)

Origin Seeder

csx-seed

Verification receipts

• go 1.26 · linux alpine/x64 · docker · CONTAINER_RUN · compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS · golang@1 · 2026-08-17 · ed25519:d91480838ac982c9