// Copyright 2015 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
package nat
import (
"bytes"
"net"
"testing"
"time"
)
// This test checks that autodisc doesn't hang and returns
// consistent results when multiple goroutines call its methods
// concurrently.
func TestAutoDiscRace(t *testing.T) {
ad := startautodisc("thing", func() Interface {
time.Sleep(500 * time.Millisecond)
return extIP{33, 44, 55, 66}
})
// Spawn a few concurrent calls to ad.ExternalIP.
type rval struct {
ip net.IP
err error
}
results := make(chan rval, 50)
for i := 0; i < cap(results); i++ {
go func() {
ip, err := ad.ExternalIP()
results <- rval{ip, err}
}()
}
// Check that they all return the correct result within the deadline.
deadline := time.After(2 * time.Second)
for i := 0; i < cap(results); i++ {
select {
case <-deadline:
t.Fatal("deadline exceeded")
case rval := <-results:
if rval.err != nil {
t.Errorf("result %d: unexpected error: %v", i, rval.err)
}
wantIP := net.IP{33, 44, 55, 66}
if !bytes.Equal(rval.ip, wantIP) {
t.Errorf("result %d: got IP %v, want %v", i, rval.ip, wantIP)
}
}
}
}
