Environment

Any number of Win32 threads could access your device at the same time, so your driver should expect this and cope correctly, even if the action is just to allow exclusive access by one thread. The kernel I/O Manager helps considerably by providing a mechanism for processing your read and write requests one at a time.

Your driver should be prepared to run on a multiprocessor system. Many of your driver routines need to be reentrant to cope with this situation. You have to ensure that your driver can cope with being run on two different processors at the same time, usually in different parts of the driver and possibly at different interrupt levels. Techniques for achieving these goals are described in this book.

Ideally, you should provide a version of your driver for each available CPU platform. This means compiling a DEC Alpha version as well as 80x86.

The end user may not be using English. For most I/O, this is not a problem for a driver.

However, if you log messages to the event log, it is nice to provide messages in a language that matches the administrator's locale. It should be easy to localize any support utilities that you provide.

Finally, your driver can determine whether Windows 2000 is running as a server or as a personal workstation. Server systems might have more memory and do more I/O.