Dining Philosophers — Async
See dining philosophers for a description of the problem.
As before, you will need a local
Cargo installation for this exercise. Copy the
code below to a file called src/main.rs
, fill out the blanks, and test that
cargo run
does not deadlock:
use std::sync::Arc; use tokio::sync::mpsc::{self, Sender}; use tokio::sync::Mutex; use tokio::time; struct Fork; struct Philosopher { name: String, // left_fork: ... // right_fork: ... // thoughts: ... } impl Philosopher { async fn think(&self) { self.thoughts .send(format!("Eureka! {} has a new idea!", &self.name)) .await .unwrap(); } async fn eat(&self) { // Keep trying until we have both forks println!("{} is eating...", &self.name); time::sleep(time::Duration::from_millis(5)).await; } } static PHILOSOPHERS: &[&str] = &["Socrates", "Hypatia", "Plato", "Aristotle", "Pythagoras"]; #[tokio::main] async fn main() { // Create forks // Create philosophers // Make them think and eat // Output their thoughts }
Since this time you are using Async Rust, you’ll need a tokio
dependency. You
can use the following Cargo.toml
:
[package]
name = "dining-philosophers-async-dine"
version = "0.1.0"
edition = "2021"
[dependencies]
tokio = { version = "1.26.0", features = ["sync", "time", "macros", "rt-multi-thread"] }
Also note that this time you have to use the Mutex
and the mpsc
module from
the tokio
crate.
- Can you make your implementation single-threaded?