From 517f0703f515f8cfad2f5887d71ca6fbfbbd4d72 Mon Sep 17 00:00:00 2001 From: Josh Bleecher Snyder Date: Mon, 29 Mar 2021 13:27:21 -0700 Subject: [PATCH] conn: document retry loop in StdNetBind.Open It's not obvious on a first read what the loop is doing. Signed-off-by: Josh Bleecher Snyder --- conn/bind_std.go | 3 +++ 1 file changed, 3 insertions(+) diff --git a/conn/bind_std.go b/conn/bind_std.go index a511341..f8b8a1b 100644 --- a/conn/bind_std.go +++ b/conn/bind_std.go @@ -89,6 +89,8 @@ func (bind *StdNetBind) Open(uport uint16) (uint16, error) { return 0, ErrBindAlreadyOpen } + // Attempt to open ipv4 and ipv6 listeners on the same port. + // If uport is 0, we can retry on failure. again: port := int(uport) var ipv4, ipv6 *net.UDPConn @@ -98,6 +100,7 @@ again: return 0, err } + // Listen on the same port as we're using for ipv4. ipv6, port, err = listenNet("udp6", port) if uport == 0 && errors.Is(err, syscall.EADDRINUSE) && tries < 100 { ipv4.Close()