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- /*
- *
- * Copyright 2018 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 wait_for_ready is an example for "wait for ready".
- package main
-
- import (
- "context"
- "fmt"
- "log"
- "net"
- "sync"
- "time"
-
- "google.golang.org/grpc"
- "google.golang.org/grpc/codes"
- pb "google.golang.org/grpc/examples/features/proto/echo"
- "google.golang.org/grpc/status"
- )
-
- // server is used to implement EchoServer.
- type server struct{}
-
- func (s *server) UnaryEcho(ctx context.Context, req *pb.EchoRequest) (*pb.EchoResponse, error) {
- return &pb.EchoResponse{Message: req.Message}, nil
- }
-
- func (s *server) ServerStreamingEcho(req *pb.EchoRequest, stream pb.Echo_ServerStreamingEchoServer) error {
- return status.Error(codes.Unimplemented, "RPC unimplemented")
- }
-
- func (s *server) ClientStreamingEcho(stream pb.Echo_ClientStreamingEchoServer) error {
- return status.Error(codes.Unimplemented, "RPC unimplemented")
- }
-
- func (s *server) BidirectionalStreamingEcho(stream pb.Echo_BidirectionalStreamingEchoServer) error {
- return status.Error(codes.Unimplemented, "RPC unimplemented")
- }
-
- // serve starts listening with a 2 seconds delay.
- func serve() {
- lis, err := net.Listen("tcp", ":50053")
- if err != nil {
- log.Fatalf("failed to listen: %v", err)
- }
- s := grpc.NewServer()
- pb.RegisterEchoServer(s, &server{})
-
- if err := s.Serve(lis); err != nil {
- log.Fatalf("failed to serve: %v", err)
- }
- }
-
- func main() {
- conn, err := grpc.Dial("localhost:50053", grpc.WithInsecure())
- if err != nil {
- log.Fatalf("did not connect: %v", err)
- }
- defer conn.Close()
-
- c := pb.NewEchoClient(conn)
-
- var wg sync.WaitGroup
- wg.Add(3)
-
- // "Wait for ready" is not enabled, returns error with code "Unavailable".
- go func() {
- defer wg.Done()
-
- ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
- defer cancel()
-
- _, err := c.UnaryEcho(ctx, &pb.EchoRequest{Message: "Hi!"})
-
- got := status.Code(err)
- fmt.Printf("[1] wanted = %v, got = %v\n", codes.Unavailable, got)
- }()
-
- // "Wait for ready" is enabled, returns nil error.
- go func() {
- defer wg.Done()
-
- ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
- defer cancel()
-
- _, err := c.UnaryEcho(ctx, &pb.EchoRequest{Message: "Hi!"}, grpc.WaitForReady(true))
-
- got := status.Code(err)
- fmt.Printf("[2] wanted = %v, got = %v\n", codes.OK, got)
- }()
-
- // "Wait for ready" is enabled but exceeds the deadline before server starts listening,
- // returns error with code "DeadlineExceeded".
- go func() {
- defer wg.Done()
-
- ctx, cancel := context.WithTimeout(context.Background(), 1*time.Second)
- defer cancel()
-
- _, err := c.UnaryEcho(ctx, &pb.EchoRequest{Message: "Hi!"}, grpc.WaitForReady(true))
-
- got := status.Code(err)
- fmt.Printf("[3] wanted = %v, got = %v\n", codes.DeadlineExceeded, got)
- }()
-
- time.Sleep(2 * time.Second)
- go serve()
-
- wg.Wait()
- }
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