fix: 修正随机ttl生成

selector.go

@@ -240,18 +240,18 @@ func (f *FastestFilter) Filter(nodes []Node) []Node {
 
 	// get latency with ttl cache
 	now := time.Now().Unix()
-	r := rand.New(rand.NewSource(time.Now().UnixNano()))
 
 	var getNodeLatency = func(node Node) int {
 		if f.pingResultTTL[node.ID] < now {
 			f.mu.Lock()
 			f.pingResultTTL[node.ID] = now + 5 // tmp
-			defer f.mu.Unlock()
+			f.mu.Unlock()
 
 			// get latency
 			go func(node Node) {
 				latency := f.doTcpPing(node.Addr)
-				ttl := 300 - int64(60*r.Float64())
+				rand.Seed(time.Now().UnixNano() + int64(latency))
+				ttl := 300 - int64(60*rand.Float64())
 
 				f.mu.Lock()
 				f.pingResult[node.ID] = latency