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QNX Software Development Platform
System Architecture
The System Architecture guide accompanies the QNX OS and is intended for both application developers and end-users.
The Microkernel Instrumentation
The microkernel (procnto-smp-instr) is equipped with a sophisticated tracing and profiling mechanism that lets you monitor your system's execution in real time. This instrumentation works on both single-CPU and SMP systems.
Event control
Given the large number of activities occurring in a live system, the number of events that the kernel emits can be overwhelming (in terms of the amount of data, the processing requirements, and the resources needed to store it). But you can easily control the amount of data emitted.

QNX Momentics IDE User's Guide
QNX Software Development Platform
- Quickstart Guide
- System Architecture
  The System Architecture guide accompanies the QNX OS and is intended for both application developers and end-users.
  - The Philosophy of the QNX OS
    The primary goal of the QNX OS is to deliver the open systems POSIX API in a robust, scalable form suitable for a wide range of systems—from tiny, resource-constrained embedded systems to high-end distributed computing environments. The OS supports several processor families, including x86 and ARM.
  - The QNX OS Microkernel
    The microkernel implements the core POSIX features used in embedded realtime systems, along with the fundamental QNX OS message-passing services.
  - Interprocess Communication (IPC)
    Interprocess Communication (IPC) plays a fundamental role in the transformation of the microkernel from an embedded realtime kernel into a full-scale POSIX operating system. As various service-providing processes are added to the microkernel, IPC is the glue that connects those components into a cohesive whole.
  - The Microkernel Instrumentation
    The microkernel (procnto-smp-instr) is equipped with a sophisticated tracing and profiling mechanism that lets you monitor your system's execution in real time. This instrumentation works on both single-CPU and SMP systems.
    - Instrumentation at a glance
    - Event control
      Given the large number of activities occurring in a live system, the number of events that the kernel emits can be overwhelming (in terms of the amount of data, the processing requirements, and the resources needed to store it). But you can easily control the amount of data emitted.
      - Modes of emission
      - Ring buffer
        Rather than always emit events to an external device, the kernel can keep all of the trace events in an internal circular buffer.
    - Data interpretation
      The data of an event includes a high-precision timestamp as well as the ID number of the CPU on which the event was generated. This information helps you easily diagnose difficult timing problems, which are more likely to occur on multiprocessor systems.
    - Proactive tracing
      While the instrumented kernel provides an excellent unobtrusive method for instrumenting and monitoring processes, threads, and the state of your system in general, you can also have your applications proactively influence the event-collection process.
  - Process Manager
    The process manager is capable of creating multiple POSIX processes (each of which may contain multiple POSIX threads).
  - Dynamic Linking
    In a typical system, a number of programs will be running. Each program relies on a number of functions, some of which will be standard C library functions, like printf(), malloc(), write(), etc.
  - Resource Managers
    To give the QNX OS a great degree of flexibility, to minimize the runtime memory requirements of the final system, and to cope with the wide variety of devices that may be found in a custom embedded system, the OS allows user-written processes to act as resource managers that can be started and stopped dynamically.
  - Filesystems
    The QNX OS provides a rich variety of filesystems. Like most service-providing processes in the OS, these filesystems execute outside the kernel; applications use them by communicating via messages generated by the shared-library implementation of the POSIX API.
  - Character I/O
    A key requirement of any realtime operating system is high-performance character I/O.
  - Networking Architecture
    As with other service-providing processes in the QNX OS, the networking services execute outside the kernel. Developers are presented with a single unified interface, regardless of the configuration and number of networks involved.
  - TCP/IP Networking
    Our TCP/IP stack is included in the io-sock networking stack and uses the common FreeBSD API.
  - High Availability
    The term High Availability (HA) is commonly used in telecommunications and other industries to describe a system's ability to remain up and running without interruption for extended periods of time.
  - What is Real Time and Why Do I Need It?
    Real time is an often misunderstood—and misapplied—property of operating systems. This appendix provides a summary of some of the critical elements of realtime computing and discusses a few design considerations and benefits.
  - Glossary
- OS Components
- Graphics
- Programming
- 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 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 OS applications and systems.
Typographical Conventions, Support, and Licensing
This section describes the typographical conventions used throughout the documentation and explains how to obtain technical support.

Event control

QNX SDP8.0System ArchitectureDeveloperUser

Given the large number of activities occurring in a live system, the number of events that the kernel emits can be overwhelming (in terms of the amount of data, the processing requirements, and the resources needed to store it). But you can easily control the amount of data emitted.

Specifically, you can:

control the initial conditions that trigger event emissions
apply predefined kernel filters to dynamically control emissions
implement your own event handlers for even more filtering.

Once the data has been collected by the data-capture utility (tracelogger), it can then be analyzed. You can analyze the data in real time or offline after the relevant events have been gathered. The System Analysis tool within the IDE presents this data graphically so you can see what's going on in your system.

Page updated: May 17, 2024