Go v1.16 추가 시그널.NotifyContext 테스트

signal.Notify Context는 무엇을 할 수 있습니까?

이전의 서법

package main

import (
	"context"
	"fmt"
	"os"
	"os/signal"
	"time"
)

func main() {
	ctx, cancel := context.WithCancel(context.Background())
	c := make(chan os.Signal, 1)
	signal.Notify(c, os.Interrupt, os.Kill)
	go func() {
		select {
		case <-c:
			fmt.Fprintln(os.Stderr, "signal received")
			cancel()
		case <-ctx.Done():
		}
	}()

	doSomethingAwesome(ctx)
}

signal.NotifyContext 쓰기 사용

package main

import (
	"context"
	"fmt"
	"os"
	"os/signal"
	"time"
)

func main() {
	ctx, stop := signal.NotifyContext(context.Background(), os.Interrupt)
	defer stop()

	doSomethingAwesome(ctx)
}

signal.NotifyContext 사용 예

여러 개의 Goroutine를 시작하고 signal로 한꺼번에 끝냅니다

package main

import (
	"context"
	"fmt"
	"os"
	"os/signal"
	"sync"
)

func blocking(ctx context.Context, wg *sync.WaitGroup) {
	defer wg.Done()
	fmt.Println("worker started")
	<-ctx.Done()
	fmt.Println("worker canceled")
}

func main() {
	ctx, stop := signal.NotifyContext(context.Background(), os.Interrupt)
	defer stop()

	var wg sync.WaitGroup
	wg.Add(3)
	go blocking(ctx, &wg)
	go blocking(ctx, &wg)
	go blocking(ctx, &wg)

	wg.Wait()
}

웹 서버를 꺼서graceful로 만들기

package main

import (
	"context"
	"fmt"
	"io"
	"log"
	"net/http"
	"os"
	"os/signal"
	"time"
)

func main() {
	ctx, stop := signal.NotifyContext(context.Background(), os.Interrupt)
	defer stop()

	http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
		io.WriteString(w, "hello!")
	})

	server := &http.Server{
		Addr:    ":8080",
		Handler: nil,
	}
	go func() {
		<-ctx.Done()
		ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
		defer cancel()
		server.Shutdown(ctx)
	}()
	fmt.Println("starting server at :8080")
	log.Fatal(server.ListenAndServe())
}

최후

참고 자료