Dining Philosophers —- Async

查看哲学家进餐以获取问题的描述。

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:

  1. use std::sync::Arc;
  2. use tokio::sync::mpsc::{self, Sender};
  3. use tokio::sync::Mutex;
  4. use tokio::time;
  6. struct Fork;
  8. struct Philosopher {
  9.     name: String,
  10.     // left_fork: ...
  11.     // right_fork: ...
  12.     // thoughts: ...
  13. }
  15. impl Philosopher {
  16.     async fn think(&self) {
  17.         self.thoughts
  18.             .send(format!("Eureka! {} has a new idea!", &self.name))
  19.             .await
  20.             .unwrap();
  21.     }
  23.     async fn eat(&self) {
  24.         // Keep trying until we have both forks
  25.         println!("{} is eating...", &self.name);
  26.         time::sleep(time::Duration::from_millis(5)).await;
  27.     }
  28. }
  30. static PHILOSOPHERS: &[&str] =
  31.     &["Socrates", "Hypatia", "Plato", "Aristotle", "Pythagoras"];
  33. #[tokio::main]
  34. async fn main() {
  35.     // Create forks
  37.     // Create philosophers
  39.     // Make them think and eat
  41.     // Output their thoughts
  42. }

因为这次您正在使用异步Rust，您将需要一个 tokio 依赖。您可以使用以下的 Cargo.toml：

  1. [package]
  2. name = "dining-philosophers-async-dine"
  3. version = "0.1.0"
  4. edition = "2021"
  6. [dependencies]
  7. tokio = { version = "1.26.0", features = ["sync", "time", "macros", "rt-multi-thread"] }

另外，请注意，这次您必须使用来自 tokio 包的 Mutex 和 mpsc 模块。

  • Can you make your implementation single-threaded?