Circumventing immutable access introduces race condition in Worker struct

[murerfel]

Noticed this while debugging another issue.

We circumvent the immutability of an Arc<Worker> by using raw pointer casting:

worker/service/src/worker_peers_updater.rs

Line 55 in 0141955

let maybe_worker = &mut *self.worker.get_mut_worker();

. This introduces race conditions, when access is done from multiple threads (which is the case). That's the reason why Arc<T> only supports immutable functions. If we want to mutate something in the update_peers, the underlying struct must use RwLock to protect against concurrent access.

Fix this by making the methods in

worker/service/src/worker.rs

Lines 113 to 120 in 0141955

	pub trait UpdatePeers {
	fn search_peers(&self) -> WorkerResult<Vec<Url>>;
	fn set_peers(&mut self, peers: Vec<Url>) -> WorkerResult<()>;
	fn update_peers(&mut self) -> WorkerResult<()> {
	let peers = self.search_peers()?;
	self.set_peers(peers)
	}
	}

immutable and add locks in the Worker to properly manage access to the peers list.