cooptex
cooptex provides deadlock-free Mutexes. The [CoopMutex::lock
] method wraps the [std::sync::Mutex
] return value with a Result
that will request the caller to drop other held locks so another thread could make progress. This behavior is easily accomplished by using the [retry_loop
] function.
use cooptex::*;
let a = CoopMutex::new(42);
let b = CoopMutex::new(43);
retry_loop(|| {
let a_lock = a.lock()?.unwrap();
let b_lock = b.lock()?.unwrap();
assert_eq!(*a_lock + *b_lock, 85);
Ok(())
});
Guarantees
This crate aims to guarantee that multiple threads cannot possibly deadlock by acquiring locks.
This crate also will prefer threads that have lived the "longest" without completing work. Meaning, when [retry_loop
] successfully completes, it will move that thread to the end of the queue for acquiring future locks. This provides an approximately fair scheduler.
The crate is still in early development, so there may be cases that aren't covered. Please open an issue if you can reproduce a deadlock.
Non-Guarantees
This crate explicitly allows the following potentially undesired behavior:
- [
CoopMutex::lock
] may return [Retry
] when it could wait and acquire the lock without a deadlock. - [
CoopMutex::lock
] may wait arbitrarily long before returning [Retry
].
Incomplete
- We have not fully analyzed the behavior during panics. There is no
unsafe
code, so we could only possibly deadlock.
License: MIT