add: exploration comments

src/main.rs

@@ -39,6 +39,7 @@ fn main() -> io::Result<()> {
     add_interest(epoll_fd, listener_fd, listener_read_event(key))?;
 
     loop {
+        // TODO[0]: check signal and 0 contexts
         println!("\nrequests in flight: {}", request_contexts.len());
         events.clear();
         let res = match syscall!(epoll_wait(
@@ -67,6 +68,7 @@ fn main() -> io::Result<()> {
                         }
                         Err(e) => eprintln!("couldn't accept: {}", e),
                     };
+                    // TODO[0]: check signal
                     modify_interest(epoll_fd, listener_fd, listener_read_event(100))?;
                 }
                 key => {