snapshot of https://github.com/grpc/grpc-go.git (master, 2026-09-15; blobs > 131072B omitted)

examples/features/gracefulstop/client/main.go

@@ -0,0 +1,80 @@
+/*
+ *
+ * Copyright 2024 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+// Binary client demonstrates sending multiple requests to server and observe
+// graceful stop.
+package main
+
+import (
+	"context"
+	"flag"
+	"fmt"
+	"log"
+	"time"
+
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/credentials/insecure"
+	pb "google.golang.org/grpc/examples/features/proto/echo"
+)
+
+var addr = flag.String("addr", "localhost:50052", "the address to connect to")
+
+func main() {
+	flag.Parse()
+
+	conn, err := grpc.NewClient(*addr, grpc.WithTransportCredentials(insecure.NewCredentials()))
+	if err != nil {
+		log.Fatalf("Failed to create new client: %v", err)
+	}
+	defer conn.Close()
+	c := pb.NewEchoClient(conn)
+
+	ctx, cancel := context.WithTimeout(context.Background(), 20*time.Second)
+	defer cancel()
+
+	// Start a client stream and keep calling the `c.UnaryEcho` until receiving
+	// an error. Error will indicate that server graceful stop is initiated and
+	// it won't accept any new requests.
+	stream, err := c.ClientStreamingEcho(ctx)
+	if err != nil {
+		log.Fatalf("Error starting stream: %v", err)
+	}
+
+	// Keep track of successful unary requests which can be compared later to
+	// the successful unary requests reported by the server.
+	unaryRequests := 0
+	for {
+		r, err := c.UnaryEcho(ctx, &pb.EchoRequest{Message: "Hello"})
+		if err != nil {
+			log.Printf("Error calling `UnaryEcho`. Server graceful stop initiated: %v", err)
+			break
+		}
+		unaryRequests++
+		time.Sleep(200 * time.Millisecond)
+		log.Print(r.Message)
+	}
+	log.Printf("Successful unary requests made by client: %d", unaryRequests)
+
+	r, err := stream.CloseAndRecv()
+	if err != nil {
+		log.Fatalf("Error closing stream: %v", err)
+	}
+	if fmt.Sprintf("%d", unaryRequests) != r.Message {
+		log.Fatalf("Got %s successful unary requests processed from server, want: %d", r.Message, unaryRequests)
+	}
+	log.Printf("Successful unary requests processed by server and made by client are same.")
+}