xiaoyong-value

Shared state primitives for sharing state.

Overview

This crate provides shared state primitives like Mutex and RwLock.

The unsync module provides primitives tailored for single-threaded executors (like tokio::task::LocalSet).

Thread Safety in unsync

Unlike some other unsync types, xiaoyong_value::unsync::async_mutex::Mutex and xiaoyong_value::unsync::async_rwlock::RwLock are built on top of Cell and UnsafeCell. Because they do not use Rc, these types automatically implement Send if the underlying data T is Send.

However, their lock guards (e.g., MutexGuard) are explicitly !Send. This guarantees that while you can transfer the Mutex itself across threads, you cannot lock it on one thread, move the guard to another thread, and unlock it there. They must be used within the confines of a single thread at any given time.

unsync::async_rcswap::RcSwap, on the other hand, utilizes Rc and is strictly !Send.

Available Primitives

• unsync::async_mutex::Mutex: An asynchronous, single-threaded Mutex.
• unsync::async_rwlock::RwLock: An asynchronous, single-threaded Reader-Writer Lock.
• unsync::async_rcswap::RcSwap: An asynchronous primitive for atomic swapping of Rc pointers.
• unsync::rcswap::RcSwap: A synchronous primitive for atomic swapping of Rc pointers.
• sync::atomic_once::AtomicOnce: A lightweight, lock-free alternative to std::sync::OnceLock.
• sync::permanent::Permanent: Handle to a statically allocated data.