| 
						
						
							
								
							
						
						
					 | 
					 | 
					@ -78,6 +78,110 @@ receive Err(Disconnected)
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					
 | 
					 | 
					 | 
					 | 
					
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					如上,当子线程创建成功且发送消息后,主线程会接收到`Ok(1)`的消息内容,紧接着子线程结束,发送者也随着被`drop`,此时接收者又会报错,但是这次错误原因有所不同:`Disconnected`代表发送者已经被关闭。
 | 
					 | 
					 | 
					 | 
					如上,当子线程创建成功且发送消息后,主线程会接收到`Ok(1)`的消息内容,紧接着子线程结束,发送者也随着被`drop`,此时接收者又会报错,但是这次错误原因有所不同:`Disconnected`代表发送者已经被关闭。
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					
 | 
					 | 
					 | 
					 | 
					
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					#### 传输具有所有权的数据
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					使用通道来传输数据,一样要遵循Rust的所有权规则:
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					
 | 
					 | 
					 | 
					 | 
					
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					- 若值的类型实现了`Copy`特征,则直接复制一份该值,然后传输过去,例如之前的`i32`类型
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					- 若值没有实现`Copy`,则它的所有权会被转移给接收端,在发送端继续使用该值将报错
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					
 | 
					 | 
					 | 
					 | 
					
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					#### 关闭通道
 | 
					 | 
					 | 
					 | 
					一起来看看第二种情况:
 | 
				
			
			
				
				
			
		
	
		
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					```rust
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					use std::sync::mpsc;
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					use std::thread;
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					fn main() {
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					    let (tx, rx) = mpsc::channel();
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					    thread::spawn(move || {
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					        let s = String::from("我,飞走咯!");
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					        tx.send(s).unwrap();
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					        println!("val is {}", s);
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					    });
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					    let received = rx.recv().unwrap();
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					    println!("Got: {}", received);
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					}
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					```
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					以上代码中,`String`底层的字符串是存储在堆上,被没有实现`Copy`特征,当它被发送后,会将所有权从发送端的`s`转移给接收端的`received`,之后`s`将无法被使用:
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					```console
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					error[E0382]: borrow of moved value: `s`
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					  --> src/main.rs:10:31
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					   |
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					8  |         let s = String::from("我,飞走咯!");
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					   |             - move occurs because `s` has type `String`, which does not implement the `Copy` trait // 所有权被转移,由于`String`没有实现`Copy`特征
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					9  |         tx.send(s).unwrap();
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					   |                 - value moved here // 所有权被转移走
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					10 |         println!("val is {}", s);
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					   |                               ^ value borrowed here after move // 所有权被转移后,依然对s进行了借用
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					```
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					各种细节不禁令人感叹:Rust还是安全!假如没有所有权的保护,`String`字符串将被两个线程同时持有,任何一个线程对字符串内容的修改都会导致另外一个线程持有的字符串被改变,除非你故意这么设计,否则这就是不安全的隐患。
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					#### 使用for进行循环接收
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					下面来看看如何连续接收通道中的值:
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					```rust
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					use std::sync::mpsc;
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					use std::thread;
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					use std::time::Duration;
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					fn main() {
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					    let (tx, rx) = mpsc::channel();
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					    thread::spawn(move || {
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					        let vals = vec![
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					            String::from("hi"),
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					            String::from("from"),
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					            String::from("the"),
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					            String::from("thread"),
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					        ];
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					        for val in vals {
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					            tx.send(val).unwrap();
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					            thread::sleep(Duration::from_secs(1));
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					        }
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					    });
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					    for received in rx {
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					        println!("Got: {}", received);
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					    }
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					}
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					```
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					在上面代码中,主线程和子线程是并发运行的,子线程在不停的**发送消息 -> 休眠1秒**,与此同时,主线程使用`for`循环**阻塞**的从`rx`**迭代器**中接收消息,当子线程运行完成时,发送者`tx`会随之被`drop`,此时`for`循环将被终止,最终`main`线程成功结束。
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					#### 使用多发送者
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					由于子线程会拿走发送者的所有权,因此我们必须对发送者进行克隆,然后让每个线程拿走它的一份拷贝:
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					```rust
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					use std::sync::mpsc;
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					use std::thread;
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					fn main() {
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					    let (tx, rx) = mpsc::channel();
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					    let tx1 = tx.clone();
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					    thread::spawn(move || {
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					        tx.send(String::from("hi from raw tx")).unwrap();
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					    });
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					    thread::spawn(move || {
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					        tx1.send(String::from("hi from cloned tx")).unwrap();
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					    });
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					    
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					    for received in rx {
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					        println!("Got: {}", received);
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					    }
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					}
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					```
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					代码并无太大区别,就多了一个对发送者的克隆`let tx1 = tx.clone();`,然后一个子线程拿走`tx`的所有权,另一个子线程拿走`tx1`的所有权,皆大欢喜。
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					但是有几点需要注意:
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					- 需要所有的发送者都被`drop`掉后,接收者`rx`才会收到错误,进而跳出`for`循环,最终结束主线程
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					- 这里虽然用了`clone`但是并不会影响性能,因为它并不在热点代码路径中,仅仅会被执行一次
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					- 由于两个子线程谁创建完成是未知的,因此哪条消息先发送也是未知的,最终主线程的输出顺序也不确定
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					注意,上述第三点的消息顺序仅仅是因为线程创建引起的,并不代表通道中的线程是无序的,对于通道而言,先发送就先被接收,典型的`FIFO`(first in, first out)。
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					#### 消息顺序
 | 
				
			
			
		
	
		
		
			
				
					
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					 | 
					### 关闭通道
 |