Handle EINTR to avoid crashing tests when debugging

When running tests with a debugger on Linux, Mio's poll function may return
EINTR (interrupted system call) after halting on breakpoints, which causes the
test to panic.

The documentation for std::io::ErrorKind::Interrupted states that "interrupted
operations can typically be retried." This commit adds a conditional to ignore
this specific error and continue polling.

Author: hornang

tests/tlsserver.rs

@@ -385,7 +385,13 @@ pub fn run_with_config(mut listener: TcpListener, config: rustls::ServerConfig)
 
     let mut events = mio::Events::with_capacity(256);
     loop {
-        poll.poll(&mut events, None).unwrap();
+        if let Err(e) = poll.poll(&mut events, None) {
+            if e.kind() == std::io::ErrorKind::Interrupted {
+                log::debug!("I/O error {:?}", e);
+                continue;
+            }
+            panic!("I/O error {:?}", e);
+        }
 
         for event in events.iter() {
             match event.token() {