Add profiling, fix race condition with WaitGroup

src/main.go

@@ -6,6 +6,7 @@ import (
 	"net/http"
 	"os"
 	"os/signal"
+	"strconv"
 	"syscall"
 
 	"github.com/gofiber/fiber/v2"
@@ -25,7 +26,7 @@ var (
 	})
 	r          *Redis  = &Redis{}
 	conf       *Config = DefaultConfig
-	instanceID uint16
+	instanceID uint16  = 0
 )
 
 func init() {
@@ -80,6 +81,18 @@ func init() {
 }
 
 func main() {
+	if v := os.Getenv("PROFILE"); len(v) > 0 {
+		port, err := strconv.ParseUint(v, 10, 16)
+
+		if err != nil {
+			panic(err)
+		}
+
+		go Profile(uint16(port))
+
+		log.Printf("Profiler is listening on :%d\n", port)
+	}
+
 	defer r.Close()
 
 	go ListenAndServe(conf.Host, conf.Port+instanceID)

src/profiler.go

@@ -0,0 +1,15 @@
+package main
+
+import (
+	"fmt"
+	"log"
+	"net/http"
+	"net/http/pprof"
+)
+
+func Profile(port uint16) {
+	mux := http.NewServeMux()
+	mux.HandleFunc("/", pprof.Profile)
+
+	log.Fatal(http.ListenAndServe(fmt.Sprintf(":%d", port), mux))
+}

src/status.go

@@ -235,31 +235,37 @@ func GetServerIcon(host string, port uint16) ([]byte, time.Duration, error) {
 func FetchJavaStatus(host string, port uint16, enableQuery bool) JavaStatusResponse {
 	var wg sync.WaitGroup
 
-	var status interface{} = nil
-	var query *response.FullQuery = nil
-
-	go func() {
-		defer wg.Done()
-
-		if result, _ := mcutil.Status(host, port); result != nil {
-			status = result
-		} else if result, _ := mcutil.StatusLegacy(host, port); result != nil {
-			status = result
-		}
-	}()
-
 	wg.Add(1)
 
 	if enableQuery {
-		go func() {
-			defer wg.Done()
+		wg.Add(1)
+	}
 
+	var status interface{} = nil
+	var query *response.FullQuery = nil
+
+	// Status
+	{
+		go func() {
+			if result, _ := mcutil.Status(host, port); result != nil {
+				status = result
+			} else if result, _ := mcutil.StatusLegacy(host, port); result != nil {
+				status = result
+			}
+
+			wg.Done()
+		}()
+	}
+
+	// Query
+	if enableQuery {
+		go func() {
 			query, _ = mcutil.FullQuery(host, port, options.Query{
 				Timeout: time.Second,
 			})
-		}()
 
-		wg.Add(1)
+			wg.Done()
+		}()
 	}
 
 	wg.Wait()