select: add pselect syscall

This is a straight port of @abbradar's work in #276, with
two (somewhat weak) tests and a bit of documentation.

2 files changed, 56 insertions, 0 deletions

diff --git a/test/sys/mod.rs b/test/sys/mod.rs
index 31cf73b1..1b3e67aa 100644
--- a/test/sys/mod.rs
+++ b/test/sys/mod.rs
@@ -15,6 +15,7 @@ mod test_aio;
 mod test_signalfd;
 mod test_socket;
 mod test_sockopt;
+mod test_select;
 mod test_termios;
 mod test_ioctl;
 mod test_wait;
diff --git a/test/sys/test_select.rs b/test/sys/test_select.rs
new file mode 100644
index 00000000..19d12fba
--- /dev/null
+++ b/test/sys/test_select.rs
@@ -0,0 +1,55 @@
+use nix::sys::select::*;
+use nix::unistd::{pipe, write};
+use nix::sys::signal::SigSet;
+use nix::sys::time::{TimeSpec, TimeValLike};
+use std::os::unix::io::RawFd;
+
+#[test]
+pub fn test_pselect() {
+    let _mtx = ::SIGNAL_MTX
+        .lock()
+        .expect("Mutex got poisoned by another test");
+
+    let (r1, w1) = pipe().unwrap();
+    write(w1, b"hi!").unwrap();
+    let (r2, _w2) = pipe().unwrap();
+
+    let mut fd_set = FdSet::new();
+    fd_set.insert(r1);
+    fd_set.insert(r2);
+
+    let timeout = TimeSpec::seconds(10);
+    let sigmask = SigSet::empty();
+    assert_eq!(
+        1,
+        pselect(None, &mut fd_set, None, None, &timeout, &sigmask).unwrap()
+    );
+    assert!(fd_set.contains(r1));
+    assert!(!fd_set.contains(r2));
+}
+
+#[test]
+pub fn test_pselect_nfds2() {
+    let (r1, w1) = pipe().unwrap();
+    write(w1, b"hi!").unwrap();
+    let (r2, _w2) = pipe().unwrap();
+
+    let mut fd_set = FdSet::new();
+    fd_set.insert(r1);
+    fd_set.insert(r2);
+
+    let timeout = TimeSpec::seconds(10);
+    assert_eq!(
+        1,
+        pselect(
+            ::std::cmp::max(r1, r2) + 1,
+            &mut fd_set,
+            None,
+            None,
+            &timeout,
+            None
+        ).unwrap()
+    );
+    assert!(fd_set.contains(r1));
+    assert!(!fd_set.contains(r2));
+}