Merge nix-rust#780

780: Add a test for ppoll r=Susurrus a=asomers

test/test_poll.rs

@@ -1,18 +1,48 @@
 use nix::poll::*;
+use nix::sys::signal::SigSet;
+use nix::sys::time::{TimeSpec, TimeValLike};
 use nix::unistd::{write, pipe};
 
 #[test]
 fn test_poll() {
     let (r, w) = pipe().unwrap();
     let mut fds = [PollFd::new(r, POLLIN)];
 
+    // Poll an idle pipe.  Should timeout
     let nfds = poll(&mut fds, 100).unwrap();
     assert_eq!(nfds, 0);
     assert!(!fds[0].revents().unwrap().contains(POLLIN));
 
     write(w, b".").unwrap();
 
+    // Poll a readable pipe.  Should return an event.
     let nfds = poll(&mut fds, 100).unwrap();
     assert_eq!(nfds, 1);
     assert!(fds[0].revents().unwrap().contains(POLLIN));
 }
+
+// ppoll(2) is the same as poll except for how it handles timeouts and signals.
+// Repeating the test for poll(2) should be sufficient to check that our
+// bindings are correct.
+#[cfg(any(target_os = "android",
+          target_os = "dragonfly",
+          target_os = "freebsd",
+          target_os = "linux"))]
+#[test]
+fn test_ppoll() {
+    let timeout = TimeSpec::milliseconds(1);
+    let (r, w) = pipe().unwrap();
+    let mut fds = [PollFd::new(r, POLLIN)];
+
+    // Poll an idle pipe.  Should timeout
+    let nfds = ppoll(&mut fds, timeout, SigSet::empty()).unwrap();
+    assert_eq!(nfds, 0);
+    assert!(!fds[0].revents().unwrap().contains(POLLIN));
+
+    write(w, b".").unwrap();
+
+    // Poll a readable pipe.  Should return an event.
+    let nfds = ppoll(&mut fds, timeout, SigSet::empty()).unwrap();
+    assert_eq!(nfds, 1);
+    assert!(fds[0].revents().unwrap().contains(POLLIN));
+}