1 files changed, 84 insertions, 0 deletions
diff --git a/tests/ui/stdio-is-blocking.rs b/tests/ui/stdio-is-blocking.rs
new file mode 100644
index 00000000000..4b67dbf79e0
--- /dev/null
+++ b/tests/ui/stdio-is-blocking.rs
@@ -0,0 +1,84 @@
+// run-pass
+// ignore-emscripten no processes
+// ignore-sgx no processes
+
+use std::env;
+use std::io::prelude::*;
+use std::process::Command;
+use std::thread;
+
+const THREADS: usize = 20;
+const WRITES: usize = 100;
+const WRITE_SIZE: usize = 1024 * 32;
+
+fn main() {
+    let args = env::args().collect::<Vec<_>>();
+    if args.len() == 1 {
+        parent();
+    } else {
+        child();
+    }
+}
+
+fn parent() {
+    let me = env::current_exe().unwrap();
+    let mut cmd = Command::new(me);
+    cmd.arg("run-the-test");
+    let output = cmd.output().unwrap();
+    assert!(output.status.success());
+    assert_eq!(output.stderr.len(), 0);
+    assert_eq!(output.stdout.len(), WRITES * THREADS * WRITE_SIZE);
+    for byte in output.stdout.iter() {
+        assert_eq!(*byte, b'a');
+    }
+}
+
+fn child() {
+    let threads = (0..THREADS).map(|_| {
+        thread::spawn(|| {
+            let buf = [b'a'; WRITE_SIZE];
+            for _ in 0..WRITES {
+                write_all(&buf);
+            }
+        })
+    }).collect::<Vec<_>>();
+
+    for thread in threads {
+        thread.join().unwrap();
+    }
+}
+
+#[cfg(unix)]
+fn write_all(buf: &[u8]) {
+    use std::fs::File;
+    use std::mem;
+    use std::os::unix::prelude::*;
+
+    let mut file = unsafe { File::from_raw_fd(1) };
+    let res = file.write_all(buf);
+    mem::forget(file);
+    res.unwrap();
+}
+
+#[cfg(windows)]
+fn write_all(buf: &[u8]) {
+    use std::fs::File;
+    use std::mem;
+    use std::os::windows::raw::*;
+    use std::os::windows::prelude::*;
+
+    const STD_OUTPUT_HANDLE: u32 = (-11i32) as u32;
+
+    extern "system" {
+        fn GetStdHandle(handle: u32) -> HANDLE;
+    }
+
+    let mut file = unsafe {
+        let handle = GetStdHandle(STD_OUTPUT_HANDLE);
+        assert!(!handle.is_null());
+        File::from_raw_handle(handle)
+    };
+    let res = file.write_all(buf);
+    mem::forget(file);
+    res.unwrap();
+}