Hopefully fix the OSX failure in test_fsync

test/sys/test_aio.rs

@@ -83,17 +83,27 @@ fn test_fsync() {
     let mut aiocb = AioCb::from_fd( f.as_raw_fd(),
                             0,   //priority
                             SigevNotify::SigevNone);
-    let err = aiocb.fsync(AioFsyncMode::O_SYNC);
-    println!("fsync returned {:?}", err);   //why does if fail on OSX?
-    assert!(err.is_ok());
+    loop {
+        let err = aiocb.fsync(AioFsyncMode::O_SYNC);
+        if err.is_ok() {
+            break;
+        } else if err == Err(Error::from(Errno::EAGAIN)) {
+            // On OSX the initial aio_fsync sometimes fails with EAGAIN
+            thread::sleep(time::Duration::from_millis(10));
+        } else {
+            panic!("AioCb::fsync returned {:?}", err.unwrap_err());
+        }
+    }
     poll_aio(&mut aiocb).unwrap();
     aiocb.aio_return().unwrap();
 }
 
 /// `AioCb::fsync` should not modify the `AioCb` object if libc::aio_fsync returns
 /// an error
+// Skip on Linux, because Linux's AIO implementation can't detect errors
+// synchronously
 #[test]
-#[cfg(target_env = "freebsd")]
+#[cfg(any(target_env = "freebsd", target_env = "macos"))]
 fn test_fsync_error() {
     const INITIAL: &'static [u8] = b"abcdef123456";
     // Create an invalid AioFsyncMode
@@ -176,8 +186,10 @@ fn test_read() {
 
 /// `AioCb::read` should not modify the `AioCb` object if libc::aio_read returns
 /// an error
+// Skip on Linux, because Linux's AIO implementation can't detect errors
+// synchronously
 #[test]
-#[cfg(target_env = "freebsd")]
+#[cfg(any(target_env = "freebsd", target_env = "macos"))]
 fn test_read_error() {
     const INITIAL: &'static [u8] = b"abcdef123456";
     let rbuf = Rc::new(vec![0; 4].into_boxed_slice());
@@ -268,8 +280,10 @@ fn test_write() {
 
 /// `AioCb::write` should not modify the `AioCb` object if libc::aio_write returns
 /// an error
+// Skip on Linux, because Linux's AIO implementation can't detect errors
+// synchronously
 #[test]
-#[cfg(target_env = "freebsd")]
+#[cfg(any(target_env = "freebsd", target_env = "macos"))]
 fn test_write_error() {
     let wbuf = "CDEF".to_string().into_bytes();
     let mut aiocb = AioCb::from_slice( 666, // An invalid file descriptor
@@ -498,7 +512,7 @@ fn test_lio_listio_read_immutable() {
 // library should wait for the AioCb's completion.
 #[test]
 #[should_panic(expected = "Dropped an in-progress AioCb")]
-#[cfg_attr(all(target_env = "musl", target_arch = "x86_64"), ignore)]
+#[cfg_attr(target_env = "musl", ignore)]
 fn test_drop() {
     const WBUF: &'static [u8] = b"CDEF";