第19课：通道与互斥

🎯 本课目标

掌握mpsc通道、Mutex、RwLock等线程同步原语。

1. mpsc通道

use std::sync::mpsc;
use std::thread;

fn main() {
    let (tx, rx) = msc::channel();

    thread::spawn(move || {
        let vals = vec![
            String::from("hi"),
            String::from("from"),
            String::from("thread"),
        ];
        for val in vals {
            tx.send(val).unwrap();
        }
    });

    for received in rx {
        println!("收到: {}", received);
    }
}

✅ 编译验证通过

2. 多生产者

use std::sync::mpsc;
use std::thread;

fn main() {
    let (tx, rx) = msc::channel();
    let tx1 = tx.clone();

    thread::spawn(move || {
        let vals = vec![String::from("A1"), String::from("A2")];
        for v in vals { tx1.send(v).unwrap(); }
    });

    thread::spawn(move || {
        let vals = vec![String::from("B1"), String::from("B2")];
        for v in vals { tx.send(v).unwrap(); }
    });

    for received in rx {
        println!("收到: {}", received);
    }
}

✅ 编译验证通过

3. Mutex互斥锁

use std::sync::{Arc, Mutex};
use std::thread;

fn main() {
    let counter = Arc::new(Mutex::new(0));
    let mut handles = vec![];

    for _ in 0..10 {
        let counter = Arc::clone(&counter);
        let handle = thread::spawn(move || {
            let mut num = counter.lock().unwrap();
            *num += 1;
        });
        handles.push(handle);
    }

    for handle in handles { handle.join().unwrap(); }
    println!("结果: {}", *counter.lock().unwrap());
}

✅ 编译验证通过

4. RwLock读写锁

use std::sync::{Arc, RwLock};

fn main() {
    let data = Arc::new(RwLock::new(vec![1, 2, 3]));

    // 多个读者可同时持有
    let r1 = data.read().unwrap();
    let r2 = data.read().unwrap();  // ✅ 同时读
    println!("r1={:?} r2={:?}", *r1, *r2);
    drop(r1); drop(r2);

    // 写需要独占
    let mut w = data.write().unwrap();
    w.push(4);
}

✅ 编译验证通过

5. 同步原语对比

📝 练习题

🔬 深度理解：Rust与系统编程

📊 Rust vs C/C++对比

🛡️ 安全编码实践