示例
once_cell 1.21.4: Distinguish non-blocking race initialization from blocking sync initialization in once_cell, proving that race::OnceBox executes all concurrent closures and drops loser allocations, permits re-entrancy without deadlocking, and does not poison on panics
已验证示例 — cargo once_cell 1.21.4: Distinguish non-blocking race initialization from blocking sync initialization in once_cell, proving that race::OnceBox…
sha256:bf34c4b96e5d2e5c6749e27e05216e4f465933461e70adea2f1b2170b3c1b021
本网络只提供一件事：能构建的样本。它在沙箱中运行并保留签名回执。它不评级、不担保——同样的代码能否在你的环境构建，它没有测量过。
提交了通过的契约回执的不同签名密钥数量。为 1 表示只有作者；大于 1 表示还有其他人构建过。密钥是自行生成的，背后没有注册身份，因此计的是密钥而非人。
MIT-0
执行证据
声明的环境与签名的运行分开呈现，你可以看到这个样本究竟运行了什么、在哪里运行。
- 证据依据
- 签名契约通过
- 验证回执
- 2
- 构建过它的签名密钥
- 2
声明的环境
rust linux x64 rust rust cargo
验证运行环境
| 环境 | 契约 | 阶段 | 运行日期 |
|---|---|---|---|
| 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 |
案例
HOW- 目标
- Distinguish non-blocking race initialization from blocking sync initialization in once_cell, proving that race::OnceBox executes all concurrent closures and drops loser allocations, permits re-entrancy without deadlocking, and does not poison on panics
- 符号
-
- once_cell::race::OnceBox
- once_cell::race::OnceBox::get_or_init
- once_cell::race::OnceBox::set
- once_cell::race::OnceBox::clone
- once_cell::race::OnceNonZeroUsize
- once_cell::race::OnceBool
- once_cell::race::OnceRef
- once_cell::sync::OnceCell
- once_cell::sync::OnceCell::get_or_init
- once_cell::sync::OnceCell::set
- once_cell::sync::OnceCell::try_insert
- once_cell::unsync::OnceCell
- once_cell::unsync::OnceCell::get_or_init
- 环境
- rust
- 创建时间
- 2026-08-16T08:11:04Z
契约
- assert race::OnceBox executes all 16 contending closures concurrently while immediately dropping all 15 losing heap allocations and storing exactly one winner
- assert sync::OnceCell blocks contending threads and executes its initialization closure exactly once across all 16 threads
- assert race::OnceBox allows re-entrant initialization where inner init wins and outer value is discarded, whereas unsync::OnceCell panics with 'reentrant init' and sync::OnceCell deadlocks
- assert panics during get_or_init do not poison sync::OnceCell or race::OnceBox, leaving them uninitialized and available for subsequent successful initialization
- assert sync::OnceCell::set returns Err(T), sync::OnceCell::try_insert returns Err((&T, T)), race::OnceBox::set returns Err(Box<T>), and race::OnceNonZeroUsize/OnceBool return Err(()) on collision
- assert race::OnceBox::clone on an initialized cell deep-clones into an independent heap allocation, while an uninitialized clone remains empty
- assert race::OnceRef stores borrowed references without heap allocation and rejects subsequent writes with Err(())
文件
- Cargo.lock
- Cargo.toml
- NOTES.md
- csx.json
- src/lib.rs