Windows® 2000 Device Driver Book: A Guide for Programmers, Second Edition, The

Chapter 7. Driver Dispatch Routines

CHAPTER OBJECTIVES

• Announcing Driver Dispatch Routines

• Writing Driver Dispatch Routines

• Processing Read and Write Requests

• Code Example: A Loopback Device

• Extending the Dispatch Interface

• Testing Driver Dispatch Routines

• Summary

Getting a driver to load is the first step, but ultimately the job of a driver is to respond to I/O requests—from user-mode applications or from other parts of the system. Windows 2000 drivers process these requests by implementing Dispatch routines. The I/O Manager in response to a request calls these routines. This chapter describes the basic Dispatch routines and explains the overall process of handling I/O requests.