Shorten mutex in DNS probe

Author: huangsam

pkg/dns/search.go

@@ -29,18 +29,16 @@ func SearchByProbe(name string, max int) ([]model.DNSResult, error) {
 		go func() {
 			defer wg.Done()
 			for domain := range domainChan {
-				mu.Lock()
-				if len(result) >= max {
-					return
-				}
-				mu.Unlock()
 				fullDomain := fmt.Sprintf("%s.%s", name, domain)
 				ips, err := net.LookupIP(fullDomain)
 				if err != nil {
 					errorCount++
 				}
 				mu.Lock()
 				result = append(result, model.DNSResult{FQDN: fullDomain, IPList: ips})
+				if len(result) >= max {
+					return
+				}
 				mu.Unlock()
 			}
 		}()