Function killProcessTree

backend/xray/process_windows.go:117–163

killProcessTree kills a process and all its children on Windows

(pid int)

// killProcessTree kills a process and all its children on Windows
func killProcessTree(pid int) error {
	proc, err := os.FindProcess(pid)
	if err != nil {
		// Process might not exist, check if it's running
		if !isProcessRunning(pid) {
			return nil
		}
		return fmt.Errorf("failed to find process %d: %w", pid, err)
	}

	// Try graceful termination first (CTRL_BREAK_EVENT for process groups)
	// For process groups created with CREATE_NEW_PROCESS_GROUP, we need to use
	// GenerateConsoleCtrlEvent to send signals to the group
	_ = proc.Signal(syscall.SIGTERM)

	// Use taskkill with /T flag to kill process tree (parent and all children)
	// /F forces termination, /T kills child processes, /PID specifies the process
	cmd := exec.Command("taskkill", "/F", "/T", "/PID", strconv.Itoa(pid))
	output, err := cmd.CombinedOutput()
	if err != nil {
		// Check if process is already dead (taskkill returns error if process not found)
		if !isProcessRunning(pid) {
			return nil
		}
		// Check if error is because process doesn't exist
		outputStr := strings.ToLower(string(output))
		if strings.Contains(outputStr, "not found") || strings.Contains(outputStr, "does not exist") {
			return nil
		}
		return fmt.Errorf("failed to kill process tree %d: %w (output: %s)", pid, err, string(output))
	}

	// Give it a moment to terminate
	// Verify it's actually dead
	if !isProcessRunning(pid) {
		return nil
	}

	// If still running, try one more time with more aggressive approach
	// This shouldn't normally happen, but just in case
	time.Sleep(100 * time.Millisecond)
	if !isProcessRunning(pid) {
		return nil
	}

	return fmt.Errorf("process %d is still running after kill attempt", pid)
}

// verifyProcessDead checks if a process is actually dead
func verifyProcessDead(pid int) error {