third_party/mdns: fix a data race
Fix a data race on accessing 'host' field.
(I'll add README.google once p@ updates his package to match this.)
Change-Id: I6fee111d13124207a1963dca3f30071c7be49812
diff --git a/go/src/github.com/presotto/go-mdns-sd/mdns.go b/go/src/github.com/presotto/go-mdns-sd/mdns.go
index daf492d..9f65d65 100644
--- a/go/src/github.com/presotto/go-mdns-sd/mdns.go
+++ b/go/src/github.com/presotto/go-mdns-sd/mdns.go
@@ -206,6 +206,10 @@
host string
}
+type updateRequest struct {
+ host string
+}
+
type watchedService struct {
c *sync.Cond
gen int
@@ -230,6 +234,7 @@
announce chan announceRequest
goodbye chan goodbyeRequest
lookup chan lookupRequest
+ update chan updateRequest
refreshAlarm chan struct{}
cleanupAlarm chan struct{}
@@ -328,6 +333,7 @@
s.announce = make(chan announceRequest)
s.goodbye = make(chan goodbyeRequest)
s.lookup = make(chan lookupRequest)
+ s.update = make(chan updateRequest)
s.refreshAlarm = make(chan struct{})
s.cleanupAlarm = make(chan struct{})
@@ -357,12 +363,11 @@
s.Stop()
return nil, errors.New("host name in use")
}
- s.hostName = host
- s.hostFQDN = hostFQDN(host)
+ s.update <- updateRequest{host}
}
// Announce ourselves if the host name is set.
- if len(s.hostName) > 0 {
+ if len(host) > 0 {
s.refreshAlarm <- struct{}{}
}
@@ -706,6 +711,9 @@
mifc.cache.Lookup(req.name, req.rrtype, req.rc)
}
close(req.rc)
+ case req := <-s.update:
+ s.hostName = req.host
+ s.hostFQDN = hostFQDN(req.host)
case <-s.refreshAlarm:
// Reannounce all services. We need to do this before the TTLs run out. As a side
// effect this reannounces the host address RRs.
