process: Add regression test for signal starvation

tests/issue_42.rs

@@ -0,0 +1,47 @@
+#![cfg(unix)]
+
+extern crate futures;
+extern crate tokio_process;
+
+use futures::{Future, IntoFuture, Stream, stream};
+use std::process::{Command, Stdio};
+use std::sync::Arc;
+use std::sync::atomic::{AtomicBool, Ordering};
+use std::thread;
+use std::time::Duration;
+use tokio_process::CommandExt;
+
+fn run_test() {
+    let finished = Arc::new(AtomicBool::new(false));
+    let finished_clone = finished.clone();
+
+    thread::spawn(move || {
+        let _ = stream::iter_ok((0..2).into_iter())
+            .map(|i| Command::new("echo")
+                 .arg(format!("I am spawned process #{}", i))
+                 .stdin(Stdio::null())
+                 .stdout(Stdio::null())
+                 .stderr(Stdio::null())
+                 .spawn_async()
+                 .into_future()
+                 .flatten()
+            )
+            .buffered(2)
+            .collect()
+            .wait();
+
+        finished_clone.store(true, Ordering::SeqCst);
+    });
+
+    thread::sleep(Duration::from_millis(100));
+    assert!(finished.load(Ordering::SeqCst), "FINISHED flag not set, maybe we deadlocked?");
+}
+
+#[test]
+fn issue_42() {
+    let max = 10;
+    for i in 0..max {
+        println!("running {}/{}", i, max);
+        run_test()
+    }
+}