[RSDK-6030] add Status() to ManagedProcess (#260)

pexec/managed_process.go

@@ -32,6 +32,10 @@ type ManagedProcess interface {
 	// Stop signals and waits for the process to stop. An error is returned if
 	// there's any system level issue stopping the process.
 	Stop() error
+
+	// Status return nil when the process is both alive and owned.
+	// If err is non-nil, process may be a) alive but not owned or b) dead.
+	Status() error
 }
 
 // NewManagedProcess returns a new, unstarted, from the given configuration.
@@ -102,6 +106,12 @@ func (p *managedProcess) ID() string {
 	return p.id
 }
 
+func (p *managedProcess) Status() error {
+	p.mu.Lock()
+	defer p.mu.Unlock()
+	return p.cmd.Process.Signal(syscall.Signal(0))
+}
+
 func (p *managedProcess) Start(ctx context.Context) error {
 	p.mu.Lock()
 	defer p.mu.Unlock()

pexec/managed_process_test.go

@@ -182,7 +182,9 @@ func TestManagedProcessStart(t *testing.T) {
 
 			<-watcher.Events
 
+			test.That(t, proc.Status(), test.ShouldBeNil)
 			test.That(t, proc.Stop(), test.ShouldBeNil)
+			test.That(t, proc.Status().Error(), test.ShouldContainSubstring, "process already finished")
 
 			rd, err := os.ReadFile(tempFile.Name())
 			test.That(t, err, test.ShouldBeNil)
@@ -348,13 +350,15 @@ func TestManagedProcessStop(t *testing.T) {
 
 		<-watcher.Events
 
+		test.That(t, proc.Status(), test.ShouldBeNil)
 		err = proc.Stop()
 		if runtime.GOOS == "windows" {
 			test.That(t, err, test.ShouldBeNil)
 		} else {
 			test.That(t, err, test.ShouldNotBeNil)
 			test.That(t, err.Error(), test.ShouldContainSubstring, "exit status 1")
 		}
+		test.That(t, proc.Status(), test.ShouldNotBeNil)
 
 		proc = NewManagedProcess(ProcessConfig{
 			Name: "bash",
@@ -408,9 +412,11 @@ done`, tempFile.Name()))
 		}, logger)
 		test.That(t, proc.Start(context.Background()), test.ShouldBeNil)
 		<-watcher.Events
+		test.That(t, proc.Status(), test.ShouldBeNil)
 		err = proc.Stop()
 		test.That(t, err, test.ShouldNotBeNil)
 		test.That(t, err.Error(), test.ShouldContainSubstring, "exit status 115")
+		test.That(t, proc.Status(), test.ShouldNotBeNil)
 
 		for _, signal := range knownSignals {
 			t.Run(fmt.Sprintf("sig=%s", sigStr(signal)), func(t *testing.T) {
@@ -699,3 +705,10 @@ func (fp *fakeProcess) Stop() error {
 	}
 	return nil
 }
+
+func (fp *fakeProcess) Status() error {
+	if fp.stopErr || fp.startErr {
+		return errors.New("dead")
+	}
+	return nil
+}

pexec/managed_process_windows.go

@@ -25,6 +25,7 @@ func parseSignal(sigStr, name string) (syscall.Signal, error) {
 	return 0, errors.New("signals not supported on Windows")
 }
 
+
 func (p *managedProcess) sysProcAttr() (*syscall.SysProcAttr, error) {
 	ret := &syscall.SysProcAttr{
 		CreationFlags: syscall.CREATE_NEW_PROCESS_GROUP,