To ensure successful development of a real-time application, designers and developers must carefully analyze how to efficiently partition the application. They must also establish the correct balance between non-real-time (Windows) processes and real-time (RTSS) processes and determine the interface between them.
If, for example, there is time-critical processing in Windows processes, too much non-time-critical processing in RTSS processes, or too much synchronization or data flow across the process interfaces, the application's performance, usability, and overall ease of development and maintenance will be jeopardized. An initial investment of time spent analyzing the various tradeoffs and designs in this critical architecture area will be worthwhile to both developers and their users.
Testing Real-Time Applications
The RTX64 SDK provides support for debugging RTSS applications within the Microsoft Visual Studio environment (See Supported Visual Studio Versions). However, in some cases, the initial development and testing of real-time application components, including device drivers is most easily done in the Windows environment. Because of how RTX64 was designed, switching between an RTX64-enabled application and an RTSS application requires no code changes.
NOTE: Some API calls are supported only in RTX64. If you use any of those API calls, you cannot debug your application as a Windows application.
The only changes necessary are in regards to the linking of the application. RTX64 provides a Visual Studio template that provides configurations for RTX64-enabled applications and RTSS applications, so switching between application types is as simple as selecting a configuration. For details about debugging RTSS applications, in Visual Studio, see Introduction to Debugging RTSS Applications.
Starting an RTSS Process
Several methods are available for starting RTSS processes. During development and testing, you will typically start RTSS processes from the RTX64 Task Manager or a command prompt with optional command line arguments or by double-clicking on the RTSS executable file icon in Windows Explorer. For final applications, you might also launch RTSS processes directly from a Windows process. To create and launch the RTSS process directly, you will use the Windows RtCreateProcess call to create and start the specified RTSS process.
Stopping an RTSS Process
An RTSS process stops when:
- The process calls the ExitProcess function.
- The process generates an exception.
- The RTX64 Subsystem shuts down.
- A Windows system shutdown occurs (either a normal shutdown sequence or an exception-initiated Windows stop screen). Unless a process has a shutdown handler, in which case the shutdown handler will run to completion before the process is stopped.
- A user or a Windows process runs the RTX64 Task Manager or RTSSkill utility available with RTX64 Runtime.
NOTE: The last methods do not provide a clean process stop and may cause unexpected results.
