From 9fc0c11fcace1afbf4f0dc0515182682f111e753 Mon Sep 17 00:00:00 2001
From: Iceber Gu <wei.cai-nat@daocloud.io>
Date: Tue, 6 Dec 2022 11:27:35 +0800
Subject: [PATCH] Sending signals by closing the channel

Signed-off-by: Iceber Gu <wei.cai-nat@daocloud.io>
---
 src/cmd/migrate-patch/main.go | 7 +++++--
 src/core/main.go              | 4 ++--
 2 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/src/cmd/migrate-patch/main.go b/src/cmd/migrate-patch/main.go
index a95eac205eb0..755fd36a8a11 100644
--- a/src/cmd/migrate-patch/main.go
+++ b/src/cmd/migrate-patch/main.go
@@ -34,20 +34,23 @@ func main() {
 		log.Fatalf("Failed to connect to Database, error: %v\n", err)
 	}
 	defer db.Close()
-	c := make(chan struct{}, 1)
+
+	c := make(chan struct{})
 	go func() {
+		defer close(c)
+
 		err := db.Ping()
 		for ; err != nil; err = db.Ping() {
 			log.Println("Failed to Ping DB, sleep for 1 second.")
 			time.Sleep(1 * time.Second)
 		}
-		c <- struct{}{}
 	}()
 	select {
 	case <-c:
 	case <-time.After(30 * time.Second):
 		log.Fatal("Failed to connect DB after 30 seconds, time out. \n")
 	}
+
 	row := db.QueryRow(pgSQLCheckColStmt)
 	var tblCount, colCount int
 	if err := row.Scan(&tblCount, &colCount); err != nil {
diff --git a/src/core/main.go b/src/core/main.go
index 101e2ca056bc..c8effb9c9d6b 100755
--- a/src/core/main.go
+++ b/src/core/main.go
@@ -97,14 +97,14 @@ func gracefulShutdown(closing, done chan struct{}, shutdowns ...func()) {
 	signal.Notify(signals, syscall.SIGINT, syscall.SIGTERM, syscall.SIGQUIT)
 	log.Infof("capture system signal %s, to close \"closing\" channel", <-signals)
 	close(closing)
-	shutdownChan := make(chan struct{}, 1)
+	shutdownChan := make(chan struct{})
 	go func() {
+		defer close(shutdownChan)
 		for _, s := range shutdowns {
 			s()
 		}
 		<-done
 		log.Infof("Goroutines exited normally")
-		shutdownChan <- struct{}{}
 	}()
 	select {
 	case <-shutdownChan: