48 lines
1.2 KiB
Rust
48 lines
1.2 KiB
Rust
async fn action(input: Option<i32>) -> Option<String> {
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// 若 input（输入）是None，则返回 None
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// 事实上也可以这么写: `let i = input?;`
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let _i = match input {
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Some(input) => input,
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None => return None,
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};
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// 这里定义一些逻辑
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Some("test".into())
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}
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#[tokio::main]
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async fn main() {
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let (tx, mut rx) = tokio::sync::mpsc::channel(128);
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let mut done = false;
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let operation = action(None);
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tokio::pin!(operation);
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tokio::spawn(async move {
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let _ = tx.send(1).await;
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let _ = tx.send(3).await;
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let _ = tx.send(2).await;
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});
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loop {
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tokio::select! {
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res = &mut operation, if !done => {
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println!("res = &mut operation, done={}", done);
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done = true;
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if let Some(v) = res {
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println!("GOT = {}", v);
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return;
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}
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}
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Some(v) = rx.recv() => {
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println!("Some(v={}) = rx.recv()", v);
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if v % 2 == 0 {
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// `.set` 是 `Pin` 上定义的方法
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operation.set(action(Some(v)));
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done = false;
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}
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}
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}
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}
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} |