The Characteristic::write() function can hang

[alistair23]

Sometimes the Characteristic::write() just never returns and hangs the entire Tokio runtime.

For example I call the function from a non async context like this

tokio::task::block_in_place(|| {
	let rt = tokio::runtime::Handle::current();
	rt.block_on(characteristic.write(data))
})

That generally works, but ever 50 or so calls the function just hangs the entire process.

As block_in_place() can have some issues I've also tried spawning a Tokio task to handle the write

        // Create write queue channel
        let (write_tx, mut write_rx) = mpsc::unbounded_channel::<WriteRequest>();

        // Spawn write worker thread
        tokio::spawn(async move {
            println!("📝 BLE Write worker thread started");
            while let Some(req) = write_rx.recv().await {
                let result = req.characteristic.write(&req.data).await;
                let _ = req.response_tx.send(result);
            }
            panic!("📝 BLE Write worker thread stopped");
        }); 

and then pass the write to the task like this

            self.write_tx.send(write_req)?;

            // Block waiting for the worker thread to complete the write
            let result = tokio::task::block_in_place(|| {
                tokio::runtime::Handle::current().block_on(response_rx)
            })

which is more robust, but eventuall also hangs.

tokio-console doesn't offer much as I can't see where in Characteristic::write() the hang occurs