Crate tendrils 

🌿 tendrils

Tiny, flexible helpers for managing shared state safely in async Rust.

✨ Features

• tokio (default): async Mutex / RwLock support
• parking_lot: lightweight sync Mutex / RwLock
• trace: adds tracing spans to lock usage
• metrics: logs lock duration (uses saydbg)

Example

use tendrils::with_state;
use std::sync::Arc;
use tokio::sync::Mutex;

#[derive(Default)]
struct AppState { count: u32 }

type Shared = Arc<Mutex<AppState>>;

#[tokio::test]
async fn main() {
    let state: Shared = Arc::new(Mutex::new(AppState::default()));

    with_state(&state, |s| {
        s.count += 1;
        println!("Count = {}", s.count);
    }).await;
}

Structs

RwTendrils

A small, ergonomic handle for shared state that is often read and occasionally written: wraps Arc<RwLock<T>>.

Tendrils

A small, ergonomic handle for shared mutable state: wraps Arc<Mutex<T>> (Tokio or parking_lot depending on features).

Functions

try_with_state

Attempts to lock a Mutex and execute a closure without blocking.

with_state

Executes a synchronous closure inside a locked Arc<Mutex<T>>.

with_state_async

Executes an async closure inside a locked Arc<Mutex<T>>, ensuring the lock is dropped before awaiting the future.

with_state_read

Executes a read-only closure inside a locked Arc<RwLock<T>>.

with_state_write

Executes a write closure inside a locked Arc<RwLock<T>>.