rust - 在Rust中中断std::io::read()

Question

我一直试图编写一个在单独的线程中调用系统命令的应用程序。
关键特征是我希望能够终止该命令，并根据请求从主线程调用一个新命令。
我的辅助线程如下所示:

let (tx, rx): (mpsc::Sender<String>, mpsc::Receiver<String>) = mpsc::channel();

let child_handle = stoppable_thread::spawn(move |stop| {
  let mut child = Command::new("[the program]").arg(format!("-g {}", gain)).stdout(Stdio::piped()).spawn().expect("naw man");
  let mut childout = child.stdout.as_mut().unwrap();
  while !stop.get() {
    let mut buffer = [0; 128];
    childout.try_read(&mut buffer).unwrap(); // This part makes the code wait for the next output
    // Here the buffer is sent via mpsc irrelevant to the issue
}});

问题是当我发送停止信号(或者如果我使用mpsc channel 通知线程停止) 时，它将等待命令向stdout输出内容。 这是有害行为。
我该如何补救？如何中断read()函数？

Answer 1

您可以kill子进程，这将导致它关闭其输出，此时read将看到一个EOF并返回。但是，这需要将子级发送到父线程。就像是:

let (tx, rx): (mpsc::Sender<String>, mpsc::Receiver<String>) = mpsc::channel();
let (ctx, crx) = mpsc::channel();

let child_handle = stoppable_thread::spawn(move |stop| {
  let mut child = Command::new("[the program]").arg(format!("-g {}", gain)).stdout(Stdio::piped()).spawn().expect("naw man");
  let mut childout = child.stdout.take().unwrap();
  ctx.send (child);
  while !stop.get() {
    let mut buffer = [0; 128];
    childout.try_read(&mut buffer).unwrap(); // This part makes the code wait for the next output
    // Here the buffer is sent via mpsc irrelevant to the issue
}});

// When you want to stop:
let child = crx.recv().unwrap();
child.kill().unwrap();