I/O - Request (Write/Read) - IO Request Packet (IRP)

> I/O - (Input/Output|Read/Write) - Data Access

1 - About

An I/O request can be intended for any:

IO request occurs per block

I/O operations issued to a driver on behalf of the application.

I/O requests are destined to a device

  • operated by a single-layered driver
  • or reached through a multilayered driver.

I/O request can be synchronous or asynchronous

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3 - Property

3.1 - Type

  • Read
  • Write
  • Others (Control, etc…)

3.2 - Location

The location of the needed data is given via the offset.

Example: “retrieve 8 block of data starting at offset 8100”.

4 - Order

5 - OS

read and write system call

6 - IRP

The I/O request packet (IRP) is where the I/O system stores information it needs to process an I/O request. When a thread calls an I/O API, the I/O manager constructs an IRP to represent the operation as it progresses through the I/O system.

7 - Example

7.1 - Windows Read

ie CPU

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7.2 - Printer

8 - Documentation / Reference

io/request.txt · Last modified: 2018/12/27 11:50 by gerardnico