Fix another race, add test

server/server.go

@@ -1165,8 +1165,11 @@ func (s *Server) updateStatsAndPrune() {
 	}
 
 	// Print stats
+	s.mu.Lock()
+	messagesCount, topicsCount, visitorsCount := s.messages, len(s.topics), len(s.visitors)
+	s.mu.Unlock()
 	log.Info("Stats: %d messages published, %d in cache, %d topic(s) active, %d subscriber(s), %d visitor(s), %d mails received (%d successful, %d failed), %d mails sent (%d successful, %d failed)",
-		s.messages, messages, len(s.topics), subscribers, len(s.visitors),
+		messagesCount, messages, topicsCount, subscribers, visitorsCount,
 		receivedMailTotal, receivedMailSuccess, receivedMailFailure,
 		sentMailTotal, sentMailSuccess, sentMailFailure)
 }

server/server_test.go

@@ -7,6 +7,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"io"
+	"log"
 	"math/rand"
 	"net/http"
 	"net/http/httptest"
@@ -1409,6 +1410,41 @@ func TestServer_Visitor_XForwardedFor_Multiple(t *testing.T) {
 	require.Equal(t, "234.5.2.1", v.ip)
 }
 
+func TestServer_PublishWhileUpdatingStatsWithLotsOfMessages(t *testing.T) {
+	count := 1000
+	s := newTestServer(t, newTestConfig(t))
+
+	// Add lots of messages
+	log.Printf("Adding %d messages", count)
+	start := time.Now()
+	for i := 0; i < count; i++ {
+		require.Nil(t, s.messageCache.AddMessage(newDefaultMessage(fmt.Sprintf("topic%d", i), "some message")))
+	}
+	log.Printf("Done: Adding %d messages; took %s", count, time.Since(start).Round(time.Millisecond))
+
+	// Update stats
+	statsChan := make(chan bool)
+	go func() {
+		log.Printf("Updating stats")
+		start := time.Now()
+		s.updateStatsAndPrune()
+		log.Printf("Done: Updating stats; took %s", time.Since(start).Round(time.Millisecond))
+		statsChan <- true
+	}()
+	time.Sleep(50 * time.Millisecond) // Make sure it starts first
+
+	// Publish message (during stats update)
+	log.Printf("Publishing message")
+	start = time.Now()
+	response := request(t, s, "PUT", "/mytopic", "some body", nil)
+	m := toMessage(t, response.Body.String())
+	require.Equal(t, "some body", m.Message)
+	require.True(t, time.Since(start) < 500*time.Millisecond)
+	log.Printf("Done: Publishing message; took %s", time.Since(start).Round(time.Millisecond))
+
+	<-statsChan
+}
+
 func newTestConfig(t *testing.T) *Config {
 	conf := NewConfig()
 	conf.BaseURL = "http://127.0.0.1:12345"