From 9d5cd39e83d837a429c41329175acd491c7126f0 Mon Sep 17 00:00:00 2001
From: Ainar Garipov <a.garipov@adguard.com>
Date: Fri, 12 Apr 2024 19:28:16 +0300
Subject: [PATCH] Pull request 107: svc-windows

Squashed commit of the following:

commit 6c9085076557d4b429c43bf891381808408174ba
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Fri Apr 12 19:01:08 2024 +0300

    osutil, service: windows support
---
 osutil/signal.go         | 10 ++++++++++
 osutil/signal_unix.go    | 27 +++++++++++++++++++++++++++
 osutil/signal_windows.go | 26 ++++++++++++++++++++++++++
 service/service_test.go  |  2 --
 service/signal.go        | 15 ++-------------
 service/signal_test.go   |  2 --
 testutil/context.go      | 18 ++++++++++++++++++
 7 files changed, 83 insertions(+), 17 deletions(-)
 create mode 100644 osutil/signal_unix.go
 create mode 100644 osutil/signal_windows.go
 create mode 100644 testutil/context.go

diff --git a/osutil/signal.go b/osutil/signal.go
index adf08ec..e9e03ab 100644
--- a/osutil/signal.go
+++ b/osutil/signal.go
@@ -52,3 +52,13 @@ func (n DefaultSignalNotifier) Notify(c chan<- os.Signal, sig ...os.Signal) {
 func (n DefaultSignalNotifier) Stop(c chan<- os.Signal) {
 	signal.Stop(c)
 }
+
+// IsShutdownSignal returns true if sig is a shutdown signal.
+func IsShutdownSignal(sig os.Signal) (ok bool) {
+	return isShutdownSignal(sig)
+}
+
+// NotifyShutdownSignal notifies c on receiving shutdown signals using n.
+func NotifyShutdownSignal(n SignalNotifier, c chan<- os.Signal) {
+	notifyShutdownSignal(n, c)
+}
diff --git a/osutil/signal_unix.go b/osutil/signal_unix.go
new file mode 100644
index 0000000..ebc604b
--- /dev/null
+++ b/osutil/signal_unix.go
@@ -0,0 +1,27 @@
+//go:build unix
+
+package osutil
+
+import (
+	"os"
+
+	"golang.org/x/sys/unix"
+)
+
+// isShutdownSignal returns true if sig is a Unix shutdown signal.
+func isShutdownSignal(sig os.Signal) (ok bool) {
+	switch sig {
+	case
+		unix.SIGINT,
+		unix.SIGQUIT,
+		unix.SIGTERM:
+		return true
+	default:
+		return false
+	}
+}
+
+// notifyShutdownSignal notifies c on receiving Unix shutdown signals using n.
+func notifyShutdownSignal(n SignalNotifier, c chan<- os.Signal) {
+	n.Notify(c, unix.SIGINT, unix.SIGQUIT, unix.SIGTERM)
+}
diff --git a/osutil/signal_windows.go b/osutil/signal_windows.go
new file mode 100644
index 0000000..300239f
--- /dev/null
+++ b/osutil/signal_windows.go
@@ -0,0 +1,26 @@
+//go:build windows
+
+package osutil
+
+import (
+	"os"
+	"syscall"
+)
+
+// isShutdownSignal returns true if sig is a Windows shutdown signal.
+func isShutdownSignal(sig os.Signal) (ok bool) {
+	switch sig {
+	case os.Interrupt, syscall.SIGTERM:
+		return true
+	default:
+		return false
+	}
+}
+
+// notifyShutdownSignal notifies c on receiving Windows shutdown signals using
+// n.
+func notifyShutdownSignal(n SignalNotifier, c chan<- os.Signal) {
+	// syscall.SIGTERM is processed automatically.  See go doc os/signal,
+	// section Windows.
+	n.Notify(c, os.Interrupt)
+}
diff --git a/service/service_test.go b/service/service_test.go
index aac3c71..cbb66dd 100644
--- a/service/service_test.go
+++ b/service/service_test.go
@@ -1,5 +1,3 @@
-//go:build unix
-
 package service_test
 
 import "time"
diff --git a/service/signal.go b/service/signal.go
index c6605e2..2f939fa 100644
--- a/service/signal.go
+++ b/service/signal.go
@@ -1,5 +1,3 @@
-//go:build unix
-
 package service
 
 import (
@@ -11,12 +9,9 @@ import (
 
 	"github.com/AdguardTeam/golibs/logutil/slogutil"
 	"github.com/AdguardTeam/golibs/osutil"
-	"golang.org/x/sys/unix"
 )
 
 // SignalHandler processes incoming signals and shuts services down.
-//
-// TODO(a.garipov): Expand to Windows.
 type SignalHandler struct {
 	logger          *slog.Logger
 	signal          chan os.Signal
@@ -73,9 +68,8 @@ func NewSignalHandler(c *SignalHandlerConfig) (h *SignalHandler) {
 		shutdownTimeout: cmp.Or(c.ShutdownTimeout, defaultSignalHandlerConf.ShutdownTimeout),
 	}
 
-	// TODO(a.garipov): Expand these to Windows.
 	notifier := cmp.Or(c.SignalNotifier, defaultSignalHandlerConf.SignalNotifier)
-	notifier.Notify(h.signal, unix.SIGINT, unix.SIGQUIT, unix.SIGTERM)
+	osutil.NotifyShutdownSignal(notifier, h.signal)
 
 	return h
 }
@@ -100,12 +94,7 @@ func (h *SignalHandler) Handle(ctx context.Context) (status osutil.ExitCode) {
 	for sig := range h.signal {
 		h.logger.InfoContext(ctx, "received", "signal", sig)
 
-		switch sig {
-		case
-			unix.SIGINT,
-			unix.SIGQUIT,
-			unix.SIGTERM:
-
+		if osutil.IsShutdownSignal(sig) {
 			var cancel context.CancelFunc
 			ctx, cancel = context.WithTimeout(ctx, h.shutdownTimeout)
 			defer cancel()
diff --git a/service/signal_test.go b/service/signal_test.go
index d876544..b71a793 100644
--- a/service/signal_test.go
+++ b/service/signal_test.go
@@ -1,5 +1,3 @@
-//go:build unix
-
 package service_test
 
 import (
diff --git a/testutil/context.go b/testutil/context.go
new file mode 100644
index 0000000..aa9c9a8
--- /dev/null
+++ b/testutil/context.go
@@ -0,0 +1,18 @@
+package testutil
+
+import (
+	"context"
+	"testing"
+	"time"
+)
+
+// ContextWithTimeout is a helper that creates a new context with timeout and
+// registers ctx's cleanup with tb.Cleanup.
+func ContextWithTimeout(tb testing.TB, timeout time.Duration) (ctx context.Context) {
+	tb.Helper()
+
+	ctx, cancel := context.WithTimeout(context.Background(), timeout)
+	tb.Cleanup(cancel)
+
+	return ctx
+}