哲學家就餐問題 --- 非同步

請參閱哲學家就餐問題，查看題目說明。

和之前一樣，這項練習需要在本機安裝 Cargo。請將以下程式碼複製到名為 src/main.rs 的檔案、填寫空白處，然後測試 cargo run 不會發生死結：

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
}

這次是使用非同步 Rust，因此會需要 tokio 依附元件。您可以使用下列 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"] }

另請注意，這次必須使用 tokio Crate 中的 Mutex 和 mpsc 模組。