add FIXME comments

Author: DebugSteven

src/shims/unix/linux/fd.rs

@@ -150,6 +150,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
         if let Some(epfd) = this.machine.file_handler.handles.get_mut(&epfd) {
             let _epfd = epfd.as_epoll_handle()?;
 
+            // FIXME return number of events ready when scheme for marking events ready exists
             Ok(Scalar::from_i32(numevents))
         } else {
             Ok(Scalar::from_i32(this.handle_not_found()?))

src/shims/unix/linux/fd/event.rs

@@ -59,6 +59,8 @@ impl FileDescriptor for Event {
         bytes: &[u8],
     ) -> InterpResult<'tcx, io::Result<usize>> {
         let v1 = self.val.get();
+        // FIXME handle blocking when addition results in exceeding the max u64 value
+        // or fail with EAGAIN if the file descriptor is nonblocking.
         let v2 = v1.checked_add(u64::from_be_bytes(bytes.try_into().unwrap())).unwrap();
         self.val.set(v2);
         assert_eq!(8, bytes.len());