ServiceTypeConstants
The Win32 service-type values. Read into ServiceManager.Type at configuration time and reported back by the SCM through ServiceState.Type at query time. Determines whether the service runs in its own process, in a shared host process, or is a kernel driver --- and, historically, whether it can interact with the desktop.
| Constant | Value | Description |
|---|---|---|
| tbServiceTypeKernelDriver | 1 | A kernel-mode driver. Not applicable to twinBASIC services --- kernel drivers are written in C and built against the Windows DDK. |
| tbServiceTypeSystemDriver | 2 | A file-system kernel driver. Same caveat as above. |
| tbServiceTypeAdapter | 4 | Legacy adapter service (network-adapter binding). Not used by modern services. |
| tbServiceTypeRecognizerDriver | 8 | A file-system-recognizer driver. Kernel-only. |
| tbServiceTypeOwnProcess | 16 | The service runs in its own dedicated EXE process. The typical setting for a one-service EXE. |
| tbServiceTypeShareProcess | 32 | The service runs alongside other services in a shared host EXE. Used when one EXE hosts multiple distinct services (ConfigureNew called more than once); the SCM keeps a single process alive that serves all of them. |
| tbServiceTypeOwnProcessInteractive | 272 | tbServiceTypeOwnProcess with the interactive bit (SERVICE_INTERACTIVE_PROCESS) set. Not supported on Windows Vista and later --- see note below. |
| tbServiceTypeShareProcessInteractive | 288 | tbServiceTypeShareProcess with the interactive bit set. Same caveat as above. |
INFO
Windows Vista and later run services in Session 0, which has no user desktop and no message-loop interaction with logged-in users --- the SERVICE_INTERACTIVE_PROCESS flag is silently ignored. The Interactive constants are kept in the enum for compatibility, but services that need user-interface elements should use a separate UI process (launched via the Services package or via inter-process communication) rather than the interactive-service mechanism.
For user-mode twinBASIC services, the only two values that matter in practice are tbServiceTypeOwnProcess and tbServiceTypeShareProcess.