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QNX Software Development Platform
QNX SDP is a cross-compiling and debugging environment, including an IDE and command-line tools, for building binary images and programs for target boards running the QNX OS 8.0.
Programming
Getting Started with the QNX OS
Getting Started with the QNX OS: A Guide for Realtime Programmers is intended to introduce you to the QNX OS and help you develop applications and resource managers for it.
Resource Managers
In this chapter, we'll take a look at what you need to understand in order to write a resource manager. Resource managers are another distintive feature of QNX OS that allow you to access services through standard POSIX calls.
The resource manager library
Before we get too far into all the issues surrounding resource managers, we have to get acquainted with the QNX OS resource manager library.
Behind the scenes at the library
You've seen that your code is responsible for providing the main message receiving loop.
The POSIX layer
The second layer provided by the resource manager library is the POSIX layer. As with the base layer, you could code a resource manager without using it, but it would be a lot of work! Before we can talk about the POSIX-layer functions in detail, we need to look at some of the base layer data structures, the messages that arrive from the clients, and the overall structure and responsibilities of a resource manager.

QNX Momentics IDE User's Guide
This User's Guide describes version 8.0 of the Integrated Development Environment (IDE) that's part of the QNX Tool Suite.
QNX Software Development Platform
QNX SDP is a cross-compiling and debugging environment, including an IDE and command-line tools, for building binary images and programs for target boards running the QNX OS 8.0.
- Quickstart Guide
- System Architecture
  The System Architecture guide accompanies the QNX OS and is intended for both application developers and end-users.
- OS Components & Operations
- Graphics
- Programming
  - Getting Started with the QNX OS
    Getting Started with the QNX OS: A Guide for Realtime Programmers is intended to introduce you to the QNX OS and help you develop applications and resource managers for it.
    - Processes and Threads
      This chapter explains the concepts behind processes and threads, and the challenges of synchronization and scheduling. A thread is a flow of execution, and a process is a collection of threads. In the QNX OS, the schedulable entity is a thread, not a process.
    - Message Passing
      In this chapter, we'll look at the most distinctive feature of QNX OS, message passing. Message passing lies at the heart of the operating system's microkernel architecture, giving the OS its modularity.
    - Interrupts
      In this chapter, we'll take a look at interrupts, how we deal with them under QNX OS, their impact on scheduling and realtime, and some interrupt-management strategies.
    - Resource Managers
      In this chapter, we'll take a look at what you need to understand in order to write a resource manager. Resource managers are another distintive feature of QNX OS that allow you to access services through standard POSIX calls.
      - What is a resource manager?
        A resource manager is simply a program with some well-defined characteristics.
      - The client's view
        We've already seen a hint of what the client expects. It expects a file-descriptor-based interface, using standard POSIX functions.
      - The resource manager's view
        Let's look at things from the resource manager's perspective.
      - The resource manager library
        Before we get too far into all the issues surrounding resource managers, we have to get acquainted with the QNX OS resource manager library.
        The library really does what we just talked about
        By way of introduction to the library, let's see (briefly) what the calls do in the /dev/null resource manager.
        Behind the scenes at the library
        You've seen that your code is responsible for providing the main message receiving loop.
        The base layer
        The bottom-most layer consists of functions that begin with resmgr_*() in their names. This class of function is concerned with the mechanics of making a resource manager work.
        The POSIX layer
        The second layer provided by the resource manager library is the POSIX layer. As with the base layer, you could code a resource manager without using it, but it would be a lot of work! Before we can talk about the POSIX-layer functions in detail, we need to look at some of the base layer data structures, the messages that arrive from the clients, and the overall structure and responsibilities of a resource manager.
      - Writing a resource manager
        Now that we've introduced the basics—how the client looks at the world, how the resource manager looks at the world, and an overview of the two cooperating layers in the library, it's time to focus on the details.
      - Handler routines
        Not all outcalls correspond to client messages—some are synthesized by the kernel, and some by the library.
      - Alphabetical listing of connect and I/O functions
        This section gives an alphabetical listing of the connect and I/O function entry points that you can fill in (the two tables passed to resmgr_attach()). Remember that if you simply call iofunc_func_init(), all these entries will be filled in with the appropriate defaults; you'd want to modify a particular entry only if you wish to handle that particular message. In the Examples section, below, you'll see some examples of the common functions.
      - Examples
        I'm now going to show you a number of cookbook examples you can cut and paste into your code, to use as a basis for your projects. These aren't complete resource managers—you'll need to add the thread pool and dispatch skeleton shown immediately below, and ensure that your versions of the I/O functions are placed into the I/O functions table after you've done the iofunc_func_init(), in order to override the defaults!
      - Advanced topics
        Now that we've covered the basics of resource managers, it's time to look at some more complicated aspects.
      - Summary
        Writing a resource manager is by far the most complicated task that we've discussed in this book.
    - Sample Programs
      This appendix contains the complete versions of some of the sample programs discussed in this book.
    - Glossary
  - Programmer's Guide
    The QNX OS Programmer's Guide covers a variety of topics that might interest developers who are building applications that will run under the QNX OS.
  - Writing a Resource Manager
- System Security Guide
  The QNX System Security Guide is intended for both system integrators who are responsible for the security of a QNX OS system and developers who want to create a QNX OS resource manager free from vulnerabilities.
- Utilities & Libraries
- Migrating to QNX OS 8.0
QNX Software in the Cloud
QNX Software in the Cloud enables developers to use the QNX OS in the Amazon cloud environment.
QNX Toolkit for Visual Studio Code
This User's Guide describes the QNX^® Toolkit for Visual Studio Code. The guide introduces you to the QNX Toolkit by explaining the QNX development environment and how to build, run, and debug your QNX^® Operating System (OS) applications and systems.
QNX Hypervisor User's Guide
This User's Guide explains the QNX hypervisor architecture and provides instructions for installing and running a QNX Hypervisor system, changing system components and configuration, and using hypervisor features such as virtual devices (vdevs).
Typographical Conventions, Support, and Licensing
This section describes the typographical conventions used throughout the documentation, explains how to obtain technical support, and provides some information about licensing.

The POSIX layer

QNX SDP8.0Getting Started with the QNX OSDeveloperUser

The second layer provided by the resource manager library is the POSIX layer. As with the base layer, you could code a resource manager without using it, but it would be a lot of work! Before we can talk about the POSIX-layer functions in detail, we need to look at some of the base layer data structures, the messages that arrive from the clients, and the overall structure and responsibilities of a resource manager.

Page updated: March 05, 2025