Fixing race conditions in the code base (#5966)

* Adding initial race detector

* Remove setting of config twice

* Fixing config file watch and config reload on license save

* Fixing config file watch and config reload on license save

* Fixing build error

* Fixing locking issue

* Fixing makefile

* Fixing race in config

* Fixing race in status unit test

* Adding EE race tests

* Fixing race in cluster info

* Removing code that's isn't needed

* Fixing some more races

* Fixing govet issue

app/web_hub.go

@@ -8,6 +8,7 @@ import (
 	"hash/fnv"
 	"runtime"
 	"runtime/debug"
+	"sync/atomic"
 
 	l4g "github.com/alecthomas/log4go"
 
@@ -18,6 +19,7 @@ import (
 
 type Hub struct {
 	connections    []*WebConn
+	count          int64
 	register       chan *WebConn
 	unregister     chan *WebConn
 	broadcast      chan *model.WebSocketEvent
@@ -43,12 +45,12 @@ func NewWebHub() *Hub {
 func TotalWebsocketConnections() int {
 	// This is racy, but it's only used for reporting information
 	// so it's probably OK
-	count := 0
+	count := int64(0)
 	for _, hub := range hubs {
-		count = count + len(hub.connections)
+		count = count + atomic.LoadInt64(&hub.count)
 	}
 
-	return count
+	return int(count)
 }
 
 func HubStart() {
@@ -248,6 +250,7 @@ func (h *Hub) Start() {
 			select {
 			case webCon := <-h.register:
 				h.connections = append(h.connections, webCon)
+				atomic.StoreInt64(&h.count, int64(len(h.connections)))
 
 			case webCon := <-h.unregister:
 				userId := webCon.UserId