refactor: refactor signal handling across platforms

- Refactor signal handling in `manager.go` to use a slice of signals instead of individual signal constants.
- Remove handling of `SIGTSTP` signal and associated logging in `manager.go`.
- Update signal sending in tests within `manager_test.go` to use `os.FindProcess` and `process.Signal` instead of `syscall.Kill`.
- Add `os` package import in `manager_test.go`.
- Create new file `signals_unix.go` with a slice of signals for Unix-based systems including `SIGINT`, `SIGTERM`, and `SIGTSTP`.
- Create new file `signals_windows.go` with a slice of signals for Windows systems including `SIGINT` and `SIGTERM`.

Signed-off-by: Bo-Yi Wu <appleboy.tw@gmail.com>

manager.go

@@ -68,9 +68,7 @@ func (g *Manager) handleSignals(ctx context.Context) {
 
  signal.Notify(
  c,
- syscall.SIGINT,
- syscall.SIGTERM,
- syscall.SIGTSTP,
+ signals...,
  )
  defer signal.Stop(c)
 
@@ -87,8 +85,6 @@ func (g *Manager) handleSignals(ctx context.Context) {
  g.logger.Infof("PID %d. Received SIGTERM. Shutting down...", pid)
  g.doGracefulShutdown()
  return
- case syscall.SIGTSTP:
- g.logger.Info("PID %d. Received SIGTSTP.", pid)
  default:
  g.logger.Infof("PID %d. Received %v.", pid, sig)
  }

manager_test.go

@@ -3,6 +3,7 @@ package graceful
 import (
  "context"
  "errors"
+ "os"
  "sync"
  "sync/atomic"
  "syscall"
@@ -240,8 +241,12 @@ func TestWithSignalSIGINT(t *testing.T) {
 
  go func() {
  time.Sleep(50 * time.Millisecond)
- if err := syscall.Kill(syscall.Getpid(), syscall.SIGINT); err != nil {
- t.Errorf("syscall error: %v", err)
+ process, err := os.FindProcess(syscall.Getpid())
+ if err != nil {
+ t.Errorf("os.FindProcess error: %v", err)
+ }
+ if err := process.Signal(syscall.SIGINT); err != nil {
+ t.Errorf("process.Signal error: %v", err)
  }
  }()
 
@@ -270,8 +275,12 @@ func TestWithSignalSIGTERM(t *testing.T) {
 
  go func() {
  time.Sleep(50 * time.Millisecond)
- if err := syscall.Kill(syscall.Getpid(), syscall.SIGTERM); err != nil {
- t.Errorf("syscall error: %v", err)
+ process, err := os.FindProcess(syscall.Getpid())
+ if err != nil {
+ t.Errorf("os.FindProcess error: %v", err)
+ }
+ if err := process.Signal(syscall.SIGTERM); err != nil {
+ t.Errorf("process.Signal error: %v", err)
  }
  }()
 

signals_unix.go

@@ -0,0 +1,11 @@
+//go:build linux || bsd || darwin
+// +build linux bsd darwin
+
+package graceful
+
+import (
+ "os"
+ "syscall"
+)
+
+var signals = []os.Signal{syscall.SIGINT, syscall.SIGTERM, syscall.SIGTSTP}

signals_windows.go

@@ -0,0 +1,11 @@
+//go:build windows
+// +build windows
+
+package graceful
+
+import (
+ "os"
+ "syscall"
+)
+
+var signals = []os.Signal{syscall.SIGINT, syscall.SIGTERM}