mpsc 多生产者单消费者

  编译:成功
  运行(退出码 0):
    共收到 12 条
    生产者 0 的序号按发送顺序到达: true
    生产者 1 的序号按发送顺序到达: true
    生产者 2 的序号按发送顺序到达: true
    到达顺序(生产者编号): 000012111222

  编译:成功
  运行(退出码 0):
    Ok(1)
    子线程已结束(它的 tx2 已 drop),但主线程手里的 tx 还活着:Err(Timeout)
    drop(tx) 之后:Err(Disconnected)

  源码:
      1 | use std::sync::mpsc;
      2 | fn main() { let (_tx, rx) = mpsc::channel::<i32>(); let _r2 = rx.clone(); }
  编译:失败
    error[E0599]: no method named `clone` found for struct `std::sync::mpsc::Receiver<T>` in the current scope
     --> <实验目录>/src/u89c.rs:2:66
      |
    2 | fn main() { let (_tx, rx) = mpsc::channel::<i32>(); let _r2 = rx.clone(); }
      |                                                                  ^^^^^ method not found in `std::sync::mpsc::Receiver<i32>`
    
    error: aborting due to 1 previous error
    
    For more information about this error, try `rustc --explain E0599`.
  源码:
      1 | use std::{sync::mpsc, thread};
      2 | fn main() { let (_tx, rx) = mpsc::channel::<i32>(); thread::scope(|s| { s.spawn(|| { let _ = rx.recv(); }); s.spawn(|| { let _ = rx.recv(); }); }); }
  编译:失败
    error[E0277]: `std::sync::mpsc::Receiver<i32>` cannot be shared between threads safely
       --> <实验目录>/src/u89d.rs:2:81
        |
      2 | ...ope(|s| { s.spawn(|| { let _ = rx.recv(); }); s.spawn(|| { let _ = rx.recv(); }); }); }
        |                ----- ^^^^^^^^^^^^^^^^^^^^^^^^^ `std::sync::mpsc::Receiver<i32>` cannot be shared between threads safely
        |                |
        |                required by a bound introduced by this call
        |
        = help: the trait `Sync` is not implemented for `std::sync::mpsc::Receiver<i32>`
        = note: required for `&std::sync::mpsc::Receiver<i32>` to implement `Send`
    note: required because it's used within this closure
       --> <实验目录>/src/u89d.rs:2:81
        |
      2 | fn main() { let (_tx, rx) = mpsc::channel::<i32>(); thread::scope(|s| { s.spawn(|| { let _ = rx.recv(); }); s.spawn(|| { let _ = rx...
        |                                                                                 ^^
    note: required by a bound in `Scope::<'scope, 'env>::spawn`
       --> <rust 标准库源码>/library/std/src/thread/scoped.rs:203:28
        |
    201 |     pub fn spawn<F, T>(&'scope self, f: F) -> ScopedJoinHandle<'scope, T>
        |            ----- required by a bound in this associated function
    202 |     where
    203 |         F: FnOnce() -> T + Send + 'scope,
        |                            ^^^^ required by this bound in `Scope::<'scope, 'env>::spawn`
    
    error: aborting due to 1 previous error
    
    For more information about this error, try `rustc --explain E0277`.

  编译:成功
  运行(退出码 0):
    处理了 20 个任务,每个任务恰好一次: true
    4 个工作线程各处理的任务数: [5, 5, 5, 5]

  编译:成功
  运行(退出码 0):
    容量 2:已发 2 个,try_send 第 3 个: Err(TrySendError::Full(..))
    接收端睡了 100 ms 才取走一个:Ok(1)
    第 3 个 send 在通道满时被阻塞了约 100 毫秒(取整到 50)
    容量 0(会合):没有接收者在等时 try_send = Err(TrySendError::Full(..))
    接收者在等时 send 成功,对方收到 7

  编译:成功
  运行(退出码 0):
    unbounded  100 万条     11.7 ms(约     12 ns/条)
    sync1      100 万条   2384.3 ms(约   2384 ns/条)
    sync1024   100 万条      7.6 ms(约      8 ns/条)