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42 lines
1.3 KiB
Rust
42 lines
1.3 KiB
Rust
// This program creates multiple asynchronous tasks that each simulate a long-running operation
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// using `async` and `await`, and each task will return how much time it took to complete.
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// The program should wait until all the tasks have finished and should collect their return values into a vector.
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use std::time::{Duration, Instant};
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use futures::executor::block_on; // This will allow us to block on async code for simplicity in an educational context
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async fn perform_task(id: usize) -> u128 {
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let start = Instant::now();
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// Simulate async work using sleep
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tokio::time::sleep(Duration::from_millis(250)).await;
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println!("Task {id} done");
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start.elapsed().as_millis()
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}
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async fn main_async() {
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let mut handles = Vec::new();
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for i in 0..10 {
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let handle = perform_task(i);
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handles.push(handle);
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}
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let mut results = Vec::new();
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for handle in handles {
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// Use `.await` to collect the results of all tasks into the `results` vector.
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results.push(handle.await);
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}
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if results.len() != 10 {
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panic!("Oh no! Some task isn't done yet!");
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}
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println!();
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for (i, result) in results.into_iter().enumerate() {
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println!("Task {i} took {result}ms");
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}
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}
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fn main() {
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block_on(main_async());
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}
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