1 #![warn(rust_2018_idioms)]
2 #![cfg(feature = "full")]
3 #![cfg(unix)]
4 
5 use futures::future::join_all;
6 use std::process::Stdio;
7 use tokio::process::Command;
8 use tokio::task;
9 
10 #[tokio::test]
issue_42()11 async fn issue_42() {
12     // We spawn a many batches of processes which should exit at roughly the
13     // same time (modulo OS scheduling delays), to make sure that consuming
14     // a readiness event for one process doesn't inadvertently starve another.
15     // We then do this many times (in parallel) in an effort to stress test the
16     // implementation to ensure there are no race conditions.
17     // See alexcrichton/tokio-process#42 for background
18     let join_handles = (0..10usize).map(|_| {
19         task::spawn(async {
20             let processes = (0..10usize).map(|i| {
21                 let mut child = Command::new("echo")
22                     .arg(format!("I am spawned process #{}", i))
23                     .stdin(Stdio::null())
24                     .stdout(Stdio::null())
25                     .stderr(Stdio::null())
26                     .kill_on_drop(true)
27                     .spawn()
28                     .unwrap();
29 
30                 async move { child.wait().await }
31             });
32 
33             join_all(processes).await;
34         })
35     });
36 
37     join_all(join_handles).await;
38 }
39