I/O Processing

Now that we’ve covered the structure and types of drivers and the data structures that support them, let’s look at how I/O requests flow through the system. I/O requests pass through several predictable stages of processing. The stages vary depending on whether the request is destined for a device operated by a single-layered driver or for a device reached through a multilayered driver. Processing varies further depending on whether the caller specified synchronous or asynchronous I/O, so we’ll begin our discussion of I/O types with these two and then move on to others.

Types of I/O

Applications have several options for the I/O requests they issue. Furthermore, the I/O manager gives drivers the choice of implementing a shortcut I/O ...

Get Windows® Internals, Sixth Edition, Part 2 now with O’Reilly online learning.

O’Reilly members experience live online training, plus books, videos, and digital content from 200+ publishers.