remove global shutdown hook

cmd/restic/cleanup.go

@@ -1,89 +1,41 @@
 package main
 
 import (
+	"context"
 	"os"
 	"os/signal"
-	"sync"
 	"syscall"
 
 	"github.com/restic/restic/internal/debug"
 )
 
-var cleanupHandlers struct {
-	sync.Mutex
-	list []func(code int) (int, error)
-	done bool
-	ch   chan os.Signal
+func createGlobalContext() context.Context {
+	ctx, cancel := context.WithCancel(context.Background())
+
+	ch := make(chan os.Signal, 1)
+	go cleanupHandler(ch, cancel)
+	signal.Notify(ch, syscall.SIGINT, syscall.SIGTERM)
+
+	return ctx
 }
 
-func init() {
-	cleanupHandlers.ch = make(chan os.Signal, 1)
-	go CleanupHandler(cleanupHandlers.ch)
-	signal.Notify(cleanupHandlers.ch, syscall.SIGINT, syscall.SIGTERM)
-}
+// cleanupHandler handles the SIGINT and SIGTERM signals.
+func cleanupHandler(c <-chan os.Signal, cancel context.CancelFunc) {
+	s := <-c
+	debug.Log("signal %v received, cleaning up", s)
+	Warnf("%ssignal %v received, cleaning up\n", clearLine(0), s)
 
-// AddCleanupHandler adds the function f to the list of cleanup handlers so
-// that it is executed when all the cleanup handlers are run, e.g. when SIGINT
-// is received.
-func AddCleanupHandler(f func(code int) (int, error)) {
-	cleanupHandlers.Lock()
-	defer cleanupHandlers.Unlock()
-
-	// reset the done flag for integration tests
-	cleanupHandlers.done = false
-
-	cleanupHandlers.list = append(cleanupHandlers.list, f)
-}
-
-// RunCleanupHandlers runs all registered cleanup handlers
-func RunCleanupHandlers(code int) int {
-	cleanupHandlers.Lock()
-	defer cleanupHandlers.Unlock()
-
-	if cleanupHandlers.done {
-		return code
+	if val, _ := os.LookupEnv("RESTIC_DEBUG_STACKTRACE_SIGINT"); val != "" {
+		_, _ = os.Stderr.WriteString("\n--- STACKTRACE START ---\n\n")
+		_, _ = os.Stderr.WriteString(debug.DumpStacktrace())
+		_, _ = os.Stderr.WriteString("\n--- STACKTRACE END ---\n")
 	}
-	cleanupHandlers.done = true
 
-	for _, f := range cleanupHandlers.list {
-		var err error
-		code, err = f(code)
-		if err != nil {
-			Warnf("error in cleanup handler: %v\n", err)
-		}
-	}
-	cleanupHandlers.list = nil
-	return code
+	cancel()
 }
 
-// CleanupHandler handles the SIGINT and SIGTERM signals.
-func CleanupHandler(c <-chan os.Signal) {
-	for s := range c {
-		debug.Log("signal %v received, cleaning up", s)
-		Warnf("%ssignal %v received, cleaning up\n", clearLine(0), s)
-
-		if val, _ := os.LookupEnv("RESTIC_DEBUG_STACKTRACE_SIGINT"); val != "" {
-			_, _ = os.Stderr.WriteString("\n--- STACKTRACE START ---\n\n")
-			_, _ = os.Stderr.WriteString(debug.DumpStacktrace())
-			_, _ = os.Stderr.WriteString("\n--- STACKTRACE END ---\n")
-		}
-
-		code := 0
-
-		if s == syscall.SIGINT || s == syscall.SIGTERM {
-			code = 130
-		} else {
-			code = 1
-		}
-
-		Exit(code)
-	}
-}
-
-// Exit runs the cleanup handlers and then terminates the process with the
-// given exit code.
+// Exit terminates the process with the given exit code.
 func Exit(code int) {
-	code = RunCleanupHandlers(code)
 	debug.Log("exiting with status code %d", code)
 	os.Exit(code)
 }

cmd/restic/global.go

@@ -96,8 +96,6 @@ var globalOptions = GlobalOptions{
 	stderr: os.Stderr,
 }
 
-var internalGlobalCtx context.Context
-
 func init() {
 	backends := location.NewRegistry()
 	backends.Register(azure.NewFactory())
@@ -111,15 +109,6 @@ func init() {
 	backends.Register(swift.NewFactory())
 	globalOptions.backends = backends
 
-	var cancel context.CancelFunc
-	internalGlobalCtx, cancel = context.WithCancel(context.Background())
-	AddCleanupHandler(func(code int) (int, error) {
-		// Must be called before the unlock cleanup handler to ensure that the latter is
-		// not blocked due to limited number of backend connections, see #1434
-		cancel()
-		return code, nil
-	})
-
 	f := cmdRoot.PersistentFlags()
 	f.StringVarP(&globalOptions.Repo, "repo", "r", "", "`repository` to backup to or restore from (default: $RESTIC_REPOSITORY)")
 	f.StringVarP(&globalOptions.RepositoryFile, "repository-file", "", "", "`file` to read the repository location from (default: $RESTIC_REPOSITORY_FILE)")

cmd/restic/main.go

@@ -3,6 +3,7 @@ package main
 import (
 	"bufio"
 	"bytes"
+	"context"
 	"fmt"
 	"log"
 	"os"
@@ -118,7 +119,13 @@ func main() {
 	debug.Log("main %#v", os.Args)
 	debug.Log("restic %s compiled with %v on %v/%v",
 		version, runtime.Version(), runtime.GOOS, runtime.GOARCH)
-	err = cmdRoot.ExecuteContext(internalGlobalCtx)
+
+	ctx := createGlobalContext()
+	err = cmdRoot.ExecuteContext(ctx)
+
+	if err == nil {
+		err = ctx.Err()
+	}
 
 	switch {
 	case restic.IsAlreadyLocked(err):
@@ -140,11 +147,13 @@ func main() {
 	}
 
 	var exitCode int
-	switch err {
-	case nil:
+	switch {
+	case err == nil:
 		exitCode = 0
-	case ErrInvalidSourceData:
+	case err == ErrInvalidSourceData:
 		exitCode = 3
+	case errors.Is(err, context.Canceled):
+		exitCode = 130
 	default:
 		exitCode = 1
 	}