[FAB-2649] Concurrent access to viper

Running gossip discovery tests in parallel rarelly results
in concurrent access to viper and concurrent map read and map write
error. This CS fix this by protecting access by lock

Change-Id: I02db2cc1c5565008de316250850492e2f98af55e
Signed-off-by: Gennady Laventman <[email protected]>

Author: gennadylaventman

gossip/discovery/discovery_impl.go

@@ -31,7 +31,6 @@ import (
 	"github.com/hyperledger/fabric/gossip/util"
 	proto "github.com/hyperledger/fabric/protos/gossip"
 	"github.com/op/go-logging"
-	"github.com/spf13/viper"
 )
 
 const defaultHelloInterval = time.Duration(5) * time.Second
@@ -42,12 +41,12 @@ var maxConnectionAttempts = 120
 
 // SetAliveTimeInterval sets the alive time interval
 func SetAliveTimeInterval(interval time.Duration) {
-	viper.Set("peer.gossip.aliveTimeInterval", interval)
+	util.SetDuration("peer.gossip.aliveTimeInterval", interval)
 }
 
 // SetAliveExpirationTimeout sets the expiration timeout
 func SetAliveExpirationTimeout(timeout time.Duration) {
-	viper.Set("peer.gossip.aliveExpirationTimeout", timeout)
+	util.SetDuration("peer.gossip.aliveExpirationTimeout", timeout)
 	aliveExpirationCheckInterval = time.Duration(timeout / 10)
 }
 
@@ -58,7 +57,7 @@ func SetAliveExpirationCheckInterval(interval time.Duration) {
 
 // SetReconnectInterval sets the reconnect interval
 func SetReconnectInterval(interval time.Duration) {
-	viper.Set("peer.gossip.reconnectInterval", interval)
+	util.SetDuration("peer.gossip.reconnectInterval", interval)
 }
 
 // SetMaxConnAttempts sets the maximum number of connection

gossip/util/misc.go

@@ -33,6 +33,8 @@ import (
 // Equals returns whether a and b are the same
 type Equals func(a interface{}, b interface{}) bool
 
+var viperLock sync.RWMutex
+
 // IndexInSlice returns the index of given object o in array
 func IndexInSlice(array interface{}, o interface{}, equals Equals) int {
 	arr := reflect.ValueOf(array)
@@ -145,6 +147,9 @@ func PrintStackTrace() {
 
 // GetIntOrDefault returns the int value from config if present otherwise default value
 func GetIntOrDefault(key string, defVal int) int {
+	viperLock.RLock()
+	defer viperLock.RUnlock()
+
 	if val := viper.GetInt(key); val != 0 {
 		return val
 	}
@@ -154,13 +159,23 @@ func GetIntOrDefault(key string, defVal int) int {
 
 // GetDurationOrDefault returns the Duration value from config if present otherwise default value
 func GetDurationOrDefault(key string, defVal time.Duration) time.Duration {
+	viperLock.RLock()
+	defer viperLock.RUnlock()
+
 	if val := viper.GetDuration(key); val != 0 {
 		return val
 	}
 
 	return defVal
 }
 
+// SetDuration stores duration key value to viper
+func SetDuration(key string, val time.Duration) {
+	viperLock.Lock()
+	defer viperLock.Unlock()
+	viper.Set(key, val)
+}
+
 // RandomInt returns, as an int, a non-negative pseudo-random integer in [0,n)
 // It panics if n <= 0
 func RandomInt(n int) int {