From d0e44deea801277ed970b17299675bf951d7d6d2 Mon Sep 17 00:00:00 2001
From: Stefan Lankes <slankes@eonerc.rwth-aachen.de>
Date: Thu, 29 Feb 2024 21:32:12 +0100
Subject: [PATCH] improve compatibility to the BSD socket layer

`poll` should return 0, if the system call timed out
---
 src/fd/mod.rs | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/src/fd/mod.rs b/src/fd/mod.rs
index 9f4646755d..b1951edc27 100644
--- a/src/fd/mod.rs
+++ b/src/fd/mod.rs
@@ -391,7 +391,17 @@ async fn poll_fds(fds: &mut [PollFd]) -> Result<u64, IoError> {
 /// monitored is specified in the `fds` argument, which is an array
 /// of structs of `PollFd`.
 pub fn poll(fds: &mut [PollFd], timeout: Option<Duration>) -> Result<u64, IoError> {
-	block_on(poll_fds(fds), timeout)
+	let result = block_on(poll_fds(fds), timeout);
+	if let Err(ref e) = result {
+		if timeout.is_some() {
+			// A return value of zero indicates that the system call timed out
+			if *e == IoError::EAGAIN {
+				return Ok(0);
+			}
+		}
+	}
+
+	result
 }
 
 /// `eventfd` creates an linux-like "eventfd object" that can be used