gistfile1.txt

    async fn update_root<V, U>(&self, ...) -> ... {
        Box::new(async {
            // 1. first we grab the lock
            let tuf = self.tuf.lock().unwrap();

            // 2. yield to the scheduler
            let signed = await!(
                repo.fetch_metadata(...)
            );

            // 4. if we're a single threaded executor, we'll never resume here
            //    because we're blocked waiting on the lock. however if we have
            //    multiple executor threads, we can eventually steal this task
            //    to handle when `fetch_metadata` finishes, unless all the
            //    threads have gotten stuck waiting for locks in the current
            //    thread.

            ...
        })
    }

    async fn update_timestamp<V, U>(&self, ...) -> ... {
        Box::new(async {
            // 3. we try to grab the lock and hang
            let tuf = self.tuf.lock().unwrap();

            ...
        })
    }