Chapter 7 QNX Platforms

7.1 Summary of QNX Platforms and Supported Features

The following table shows the supported products/features for each architecture. A ● means supported in this release, an empty cell means unsupported in this release.

Table 7.1 QNX Systems - Supported Features

RTI Architecture [1]	Supported Features
Languages
	Java [2]	Python [3]	.NET (C#) [4]	C/C++ [5]	Modern C++ [6], [7]	Protocol Buffers Extension [8]
QNX Neutrino 8.0, 8.0.2, 8.0.3 [15] x64QNX8.0qcc_cxx12.2.0 [16]				●	●	●
QNX Neutrino 8.0, 8.0.2, 8.0.3 [15] armv8QNX8.0qcc_cxx12.2.0 [16]				●	●	●
Transports
	UDP/IPv4	UDP/IPv6	Multicast	TCP/IPv4	Shared Memory (w/ zero copy) [9]
QNX Neutrino 8.0, 8.0.2, 8.0.3 x64QNX8.0qcc_cxx12.2.0	●	● [10]	●	●	●
QNX Neutrino 8.0, 8.0.2, 8.0.3 armv8QNX8.0qcc_cxx12.2.0	●	● [10]	●	●	●
Infrastructure Services
	Persistence Service	Routing Service	Recording and Replay Services	Web Integration Service
QNX Neutrino 8.0, 8.0.2 , 8.0.3 x64QNX8.0qcc_cxx12.2.0		●
QNX Neutrino 8.0, 8.0.2, 8.0.3 armv8QNX8.0qcc_cxx12.2.0		●
Connext Professional Libraries
	Request/Reply	Monitoring Library	Distributed Logger	LBED [11]	Monitoring Library 2.0
QNX Neutrino 8.0, 8.0.2, 8.0.3 x64QNX8.0qcc_cxx12.2.0	●	●	●	●	See "Observability Framework" rows below
QNX Neutrino 8.0, 8.0.2, 8.0.3 armv8QNX8.0qcc_cxx12.2.0	●	●	●	●
Core Library Features
	Monotonic Clock	CPU Core Affinity	Durable writer history & reader state	RTI DDS thread name	Backtrace	Cmake Find Package
QNX Neutrino 8.0, 8.0.2, 8.0.3 x64QNX8.0qcc_cxx12.2.0	●	●		●		●
QNX Neutrino 8.0, 8.0.2, 8.0.3 armv8QNX8.0qcc_cxx12.2.0	●	●		●		●
Tools
	Shapes Demo	Launcher	Monitor	Admin Console	System Designer	rtiddsgen server	Utilities (rtiddsping, rtiddsspy)
QNX Neutrino 8.0, 8.0.2, 8.0.3 x64QNX8.0qcc_cxx12.2.0							●
QNX Neutrino 8.0, 8.0.2, 8.0.3 armv8QNX8.0qcc_cxx12.2.0							●
Observability Framework
	Observability Collector Service	Monitoring Library 2.0
QNX Neutrino 8.0, 8.0.2, 8.0.3 x64QNX8.0qcc_cxx12.2.0		●
QNX Neutrino 8.0, 8.0.2, 8.0.3 armv8QNX8.0qcc_cxx12.2.0		●
Security Extensions
	Security Plugins (for OpenSSL) [12]	Security Plugins (for wolfSSL) [13]	TLS Support [12]	Security Plugins SDK [14]
QNX Neutrino 8.0, 8.0.2, 8.0.3 x64QNX8.0qcc_cxx12.2.0	●		●
QNX Neutrino 8.0, 8.0.2, 8.0.3 armv8QNX8.0qcc_cxx12.2.0	●	●	●	●
Add-ons
	Cloud Discovery Service	Real-Time WAN Transport	Ada Language Support	Limited Bandwidth Plugins	Queuing Service (Experimental)
QNX Neutrino 8.0, 8.0.2, 8.0.3 x64QNX8.0qcc_cxx12.2.0		●
QNX Neutrino 8.0, 8.0.2, 8.0.3 armv8QNX8.0qcc_cxx12.2.0		●

Footnotes for the above table:

1	Supports DDS 1.4, RTPS 2.5, and DDS X-Types 1.4.
2	Built with Eclipse Temurin OpenJDK 21.0.7, compatible with Java 8 and above. Also tested with AdoptOpenJDK 17.0.6 and 25.0.1.
3	Supported on Python 3.10-3.14. Free-threaded (no-GIL) builds of CPython 3.13+ are not currently supported.
4	The C# API is provided as multi-targeted .NET Standard 2.0 and 2.1 libraries, built using the .NET 10 SDK. This allows consumption from the following runtimes, per Microsoft compatibility guidance: .NET 5 and newer, .NET Core 2.1 and newer, and .NET Framework 4.8.1 and newer. Unity projects can consume the libraries on either .NET Standard 2.0 or 2.1 profiles depending on the Unity version and API Compatibility Level settings. Unity versions 2021.2 and later include support for .NET Standard 2.1, while earlier versions target .NET Standard 2.0.
5	Supports C++98 compilers or newer.
6	Tested with C++11 unless stated otherwise.
7	Supporting Modern C++ means supporting the RPC feature unless otherwise stated.
8	Only provides mapping for Modern C++. The IDL converted from a .proto file can be used with the standard mapping in the rest of the languages.
9	Zero-copy transfer over shared memory is NOT supported for Java, Ada, .NET and Python programming languages. It is only supported for C, Traditional C++, and Modern C++ programming languages.
10	No Traffic Class support.
11	Supports dynamic linking only.
12	Tested with OpenSSL 3.5.5 unless stated otherwise.
13	Tested with WolfSSL 5.8.2.
14	Tested with both OpenSSL 3.5.5 and WolfSSL 5.8.2.
15	The earliest versions of the com.qnx.qnx800.target.microkernel.core (“QNX® SDP 8.0 Kernel and libc”) component are not supported. Please update this component in your QNX 8.0 SDP installation to version 2.0.2.00388T202406131303L or higher (“Stable (GA8.0.1) July 09, 2024”) before generating the QNX system image.
16	LLVM C++ library

7.1.1 Monotonic Clock Support

See Configuring the Clock per DomainParticipant, in the RTI Connext Core Libraries User's Manual for information on the monotonic clock.

7.1.2 Support for 'Find Package' CMake Script

For information on using the 'Find Package' CMake script, see 2.5 Building with CMake.

7.1.3 Notes about Transports

• Shared Memory

The following expression can detect the two different kinds of SHMEM mutexes that RTI supports on QNX systems: posix semaphores for older QNX versions, and shared pthread mutexes for newer QNX versions, as well other shared memory resources used by Connext such as plain shared memory segments:

ls /dev/shmem/RTIOsapiSharedMemory*

To clean up the shared memory resources (both segments and mutexes), remove the relevant files listed in /dev/shmem/ and /dev/sem/. The shared resource names used by Connext begin with 'RTIOsapiSharedMemory'.

The permissions for the semaphores created by Connext are modified by the process' umask value. If you want to have shared memory support between different users, run the command "umask 000" to change the default umask value to 0 before running your Connext application.

• UDPv6: Supported. The transport is not enabled by default; the peers list must be modified to support IPv6. No Traffic Class support.

To use the UDPv6 transport, the network stack must provide IPv6 capability. Enabling UDPv6 may involve switching the network stack server and setting up IPv6 route entries.

7.2 Building Applications for QNX Platforms

The libraries on Arm v7 CPUs require a hardware FPU in the processor and are compatible with systems that have hard-float libc. See Table 7.10 Library-Creation Details for QNX Architectures for compiler flag details.

Table 7.2 Building Instructions for QNX Architectures lists the libraries you will need to link into your application.

Depending on which Connext features you want to use, you may need additional libraries; see  7.2.2 Additional Libraries for Other Features.

Make sure you are consistent in your use of static, dynamic, debug and release versions of the libraries. Do not link both static and dynamic libraries. Similarly, do not mix release and debug libraries.

Release and Debug Terminology:

Both release and debug versions of the libraries are provided. For Connext, debug libraries are created with debug symbols to facilitate debugging with gdb, for example. Release libraries do not contain debug information.

The Connext debug libraries are intended solely for development and debugging purposes. These libraries are not optimized for performance or resource consumption and may include additional diagnostic information that can affect runtime behavior. They are not intended for use in production environments. Please ensure that only the release libraries are used in production deployments. Debug libraries can be identified by the suffix "d" in their names.

Additional Documentation: 

You should also review the QNX chapter of the RTI Connext Core Libraries Getting Started Guide Addendum for Embedded Systems.

Verified Compiler Flags:

Compiler flags outside those documented in Table 7.2 Building Instructions for QNX Architectures have not been verified by RTI and can cause undefined behavior.

Table 7.2 Building Instructions for QNX Architectures

API	Library Format	Required RTI Libraries1 Choose *cpp*.* for the Traditional C++ API or *cpp2*.* for the Modern C++ API., 2 The DDS C/C++ libraries are in $(NDDSHOME)/lib/<architecture>.	Required System Libraries	Required Compiler Flags
C++ (Traditional and Modern APIs)	Static Release	libnddscorez.a libnddscz.a libnddscppz.a (or libnddscpp2z.a) librticonnextmsgcppz.a (or librticonnextmsgcpp2z.a)	-lm -lsocket	-DRTI_QNX
	Static Debug	libnddscorezd.a libnddsczd.a libnddscppzd.a (or libnddscpp2zd.a) librticonnextmsgcppzd.a (or librticonnextmsgcpp2zd.a)
	Dynamic Release	libnddscore.so libnddsc.so libnddscpp.so (or libnddscpp2.so) librticonnextmsgcpp.so (or librticonnextmsgcpp2.so)
	Dynamic Debug	libnddscored.so libnddscd.so libnddscppd.so (or libnddscpp2d.so) librticonnextmsgcppd.so (or librticonnextmsgcpp2d.so)
C	Static Release	libnddscorez.a libnddscz.a librticonnextmsgcz.a	-lm -lsocket	For 64-bit architectures: -DRTI_64BIT For all architectures: -DRTI_QNX
	Static Debug	libnddscorezd.a libnddsczd.a librticonnextmsgczd.a
	Dynamic Release	libnddscore.so libnddsc.so librticonnextmsgc.so
	Dynamic Debug	libnddscored.so libnddscd.so librticonnextmsgcd.so

7.2.1 Required Change for Building with C++ Libraries

The C++ libraries for QNX platforms are built without the -frtti flag and with the -fexceptions flag. You must build your C++ applications without -fno-exceptions in order to link with the RTI libraries. In summary:

• Do not use -fno-exceptions when building a C++ application or the build will fail.
• It is not necessary to use -fexceptions, but doing so will not cause a problem.
• It is not necessary to use -frtti, but doing so will not cause a problem.

7.2.2 Additional Libraries for Other Features

This section discusses libraries for features that are not supported for every platform. Refer to Table 7.1 QNX Systems - Supported Features to see if these libraries are supported on your platform.

If you plan to use the additional RTI libraries described in this section, they must be linked before the required RTI libraries (see Table 7.2 Building Instructions for QNX Architectures) in your included libraries for linking.

Make sure you are consistent in your use of static, dynamic, debug and release versions of the libraries. For example, if your Connext application is linked with the static release version of the Connext libraries, you will need to also use the static release version of the library. Do not link both static and dynamic libraries. Similarly, do not mix release and debug libraries.

7.2.2.1 Libraries Required for Distributed Logger

Table 7.3 Additional Libraries for using RTI Distributed Logger lists the additional libraries you will need in order to use Distributed Logger.

Table 7.3 Additional Libraries for using RTI Distributed Logger

Language	Static		Dynamic
	Release	Debug	Release	Debug
C	librtidlcz.a	librtidlczd.a	librtidlc.so	librtidcd.so
C++ (Traditional API)	librtidlcz.a librtidlcppz.a	librtidlczd.a librtidlcppzd.a	librtidlc.so librtidlcpp.so	librtidlcd.so librtidlcppd.so

7.2.2.2 Libraries Required for Monitoring

If you are statically linking your application with DDS libraries and you want to add monitoring to your application, you will also need to statically link the monitoring library. The library cannot be loaded dynamically strictly through the QoS profile because it also depends on DDS to publish its data. Therefore, it depends on DDS; the DDS functionality would cause duplicate symbols to be found, resulting in the termination of the process.

To use dynamic libraries: make sure the permissions on the .so library files are readable by everyone.

Table 7.4 Additional Libraries for Using Monitoring

Library Format	Monitoring Libraries3 These libraries are in <NDDSHOME>/lib/<architecture>.
Dynamic Release	librtimonitoring.so
Dynamic Debug	librtimonitoringd.so
Static Release	librtimonitoringz.a
Static Debug	librtimonitoringzd.a

Table 7.5 Additional Libraries for Using Monitoring Library 2.0

Library Format	Monitoring Libraries 2.0 4 These libraries are in <NDDSHOME>/lib/<architecture>.
Dynamic Release	librtimonitoring2.so
Dynamic Debug	librtimonitoringd2.so
Static Release	librtimonitoringz2.a
Static Debug	librtimonitoringzd2.a

7.2.2.3 Libraries Required for Real-Time WAN Transport

If you choose to use RTI Real-Time WAN Transport, you must download and install a separate package that contains the transport libraries. See the RTI Connext Installation Guide for details.

Using Real-Time WAN Transport requires one of the libraries in Table 7.6 Additional Libraries for Using RTI Real-Time WAN Transport APIs. Select the file appropriate for your chosen library format.

For more information, see Enabling Real-Time WAN Transport, in the RTI Connext Core Libraries User's Manual.

Table 7.6 Additional Libraries for Using RTI Real-Time WAN Transport APIs

Library Format	Real-Time WAN Transport Libraries5 These libraries are in <NDDSHOME>/lib/<architecture>.
Dynamic Release	libnddsrwt.so
Dynamic Debug	libnddsrwtd.so
Static Release	libnddsrwtz.a
Static Debug	libnddsrwtzd.a

7.2.2.4 Libraries Required for TCP Transport APIs and TLS Support

To use the TCP Transport APIs, link against the additional libraries in Table 7.7 Additional Libraries for using RTI TCP Transport APIs .

Note: Not all platforms support the TCP Transport - see Chapter 7 QNX Platforms.

Table 7.7 Additional Libraries for using RTI TCP Transport APIs

Library Format	RTI TCP Transport Libraries6 These libraries are in <NDDSHOME>/lib/<architecture>.
Dynamic Release	libnddstransporttcp.so
Dynamic Debug	libnddstransporttcpd.so
Static Release	libnddstransporttcpz.a
Static Debug	libnddstransporttcpzd.a

If you are using RTI TLS Support, also see Table 7.8 Additional Libraries for using RTI TCP Transport APIs with TLS Enabled. (Select the files appropriate for your chosen library format.) See the RTI TLS Support Release Notes for a list of supported platforms.

Table 7.8 Additional Libraries for using RTI TCP Transport APIs with TLS Enabled

Library Format	RTI TLS Libraries7 These libraries are in <NDDSHOME>/lib/<architecture>.	OpenSSL Libraries8 OpenSSL libraries are in <NDDSHOME>/third_party/openssl-3.5.5/<architecture>/<format>/lib.
Dynamic Release	libnddstls.so	libssl.so libcrypto.so
Dynamic Debug	libnddstlsd.so
Static Release	libnddstlsz.a
Static Debug	libnddstlszd.a

7.2.2.5 Libraries Required for Zero Copy Transfer Over Shared Memory

To use the Zero Copy Transfer Over Shared Memory feature, link against the additional library in Table 7.9 Additional Libraries for Zero Copy Transfer Over Shared Memory.

Table 7.9 Additional Libraries for Zero Copy Transfer Over Shared Memory

Library Format	Zero Copy Transfer Over Shared Memory Libraries9 These libraries are in <NDDSHOME>/lib/<architecture>.
Dynamic Release	libnddsmetp.so
Dynamic Debug	libnddsmetpd.so
Static Release	libnddsmetpz.a
Static Debug	libnddsmetpzd.a

7.2.3 How the Connext Libraries were Built

Table 7.10 Library-Creation Details for QNX Architectures shows the compiler flags that RTI used to build the Connext libraries. This is provided strictly for informational purposes; you do not need to use these parameters to compile your application. You may find this information useful if you are involved in any in-depth debugging.

The details for building user applications are in Chapter 2 Building Applications—Notes for All Platforms.

Table 7.10 Library-Creation Details for QNX Architectures

RTI Architecture	Library Format	Compiler Flags Used by RTI
x64QNX8.0qcc_cxx12.2.0	Static Release	-Vgcc/12.2.0,gcc_ntox86_64 -DFD_SETSIZE=512 -DSIZEOF_LONG=8 -O -Y_cxx -fexceptions -fno-strict-aliasing -fno-semantic-interposition -O -DNDEBUG -fPIC -fvisibility=hidden
	Static Debug	-Vgcc/12.2.0,gcc_ntox86_64 -lang-c++ -DFD_SETSIZE=512 -DSIZEOF_LONG=8 -O0 -Y_cxx -fexceptions -fno-strict-aliasing -fno-semantic-interposition -O0 -g -fPIC
	Dynamic Release	-Vgcc/12.2.0,gcc_ntox86_64 -lang-c++ -DFD_SETSIZE=512 -DSIZEOF_LONG=8 -O -Y_cxx -fexceptions -flto=auto -fno-strict-aliasing -fno-semantic-interposition -O -DNDEBUG -fPIE -fvisibility=hidden
	Dynamic Debug	-Vgcc/12.2.0,gcc_ntox86_64 -DFD_SETSIZE=512 -DSIZEOF_LONG=8 -O0 -Y_cxx -fexceptions -fno-strict-aliasing -fno-semantic-interposition -g -fPIC
armv8QNX8.0qcc_cxx12.2.0	Static Release	-Vgcc/12.2.0,gcc_ntoaarch64le -lang-c++ -DFD_SETSIZE=512 -DSIZEOF_LONG=8 -O -Y_cxx -fexceptions -fno-strict-aliasing -fno-semantic-interposition -O -DNDEBUG -fPIC -fvisibility=hidden
	Static Debug	-Vgcc/12.2.0,gcc_ntoaarch64le -lang-c++ -DFD_SETSIZE=512 -DSIZEOF_LONG=8 -O0 -Y_cxx -fexceptions -fno-strict-aliasing -fno-strict-aliasing -fno-semantic-interposition -g -fPIC
	Dynamic Release	-Vgcc/12.2.0,gcc_ntoaarch64le -DFD_SETSIZE=512 -DSIZEOF_LONG=8 -O -Y_cxx -fexceptions -flto=auto -fno-strict-aliasing -fno-semantic-interposition -O -DNDEBUG -fPIC -fvisibility=hidden
	Dynamic Debug	-Vgcc/12.2.0,gcc_ntoaarch64le -DFD_SETSIZE=512 -DSIZEOF_LONG=8 -O0 -Y_cxx -fexceptions -fno-strict-aliasing -fno-semantic-interposition -O0 -g -fPIC

7.3 Running Your Application

Table 7.11 Running Instructions for QNX Architectures provides details on the environment variables that must be set at run time for a QNX architecture.

Starting with Connext 6.0.1, you need the dirname tool to run the scripts in the bin directory.

Table 7.11 Running Instructions for QNX Architectures

RTI Architecture	Library Format (Release & Debug)	Environment Variables
All supported QNX architectures	Static	None required
	Dynamic	LD_LIBRARY_PATH= ${NDDSHOME}/lib/<architecture>: ${LD_LIBRARY_PATH}10 ${NDDSHOME} represents the root directory of your Connext installation. ${LD_LIBRARY_PATH} represents the value of the LD_LIBRARY_PATH variable prior to changing it to support Connext.

7.4 Thread Configuration

7.4.1 Thread Settings and Thread-Priority Definitions

See Table 7.12 Thread Settings for QNX Platforms and Table 7.13 Thread-Priority Definitions for QNX Platforms.

Table 7.12 Thread Settings for QNX Platforms

Applicable Thread	DDS_ThreadSettings_t	Platform-Specific Setting
Asynchronous Publisher, Asynchronous flushing thread	mask	OS default thread type
	priority	10
	stack_size	64 * 1024
	cpu_list	Empty CPU list (Supported on QNX platforms)
	cpu_rotation	DDS_THREAD_SETTINGS_CPU_NO_ROTATION
Database thread	mask	DDS_THREAD_SETTINGS_STDIO
	priority	8
	stack_size	64 * 1024
	cpu_list	Empty CPU list (Supported on QNX platforms)
	cpu_rotation	DDS_THREAD_SETTINGS_CPU_NO_ROTATION
Event thread	mask	DDS_THREAD_SETTINGS_STDIO | DDS_THREAD_SETTINGS_FLOATING_POINT
	priority	8
	stack_size	4 * 64 * 1024
	cpu_list	Empty CPU list (Supported on QNX platforms)
	cpu_rotation	DDS_THREAD_SETTINGS_CPU_NO_ROTATION
ReceiverPool threads	mask	DDS_THREAD_SETTINGS_STDIO | DDS_THREAD_SETTINGS_FLOATING_POINT
	priority	12
	stack_size	4 * 64 * 1024
	cpu_list	Empty CPU list (Supported on QNX platforms)
	cpu_rotation	DDS_THREAD_SETTINGS_CPU_NO_ROTATION

 

Table 7.13 Thread-Priority Definitions for QNX Platforms

Thread-Priority Definition	Operating-System Priority
THREAD_PRIORITY_DEFAULT	10
THREAD_PRIORITY_HIGH	14
THREAD_PRIORITY_ABOVE_NORMAL	12
THREAD_PRIORITY_NORMAL	10
THREAD_PRIORITY_BELOW_NORMAL	8
THREAD_PRIORITY_LOW	6

7.6 Restarting Applications on QNX Systems

Due to a limitation in the POSIX API, the allocation and the initialization of a shared memory mutex need to be done in separate steps.

The first (and only the first) Connext application that runs in the system using the shared-memory transport on a given domain will create a shared-memory mutex, in separate steps as described above, and subsequent Connext applications will attach to—but not create—this mutex, which is necessary to protect access to the shared-memory area across multiple processes.

It is possible under some extreme circumstances that the Connext application that creates the mutex crashes—or terminates ungracefully—having only partially created the mutex. If this occurs, other Connext applications will consider the mutex is still being created and will not be able to continue their execution, reporting a timeout error and indicating the mutex name.

If this situation occurs, you must manually delete the shared-memory mutex and its segment before re-launching any application in the same DDS domain. The files to delete are:

• /dev/sem/RTIOsapiSharedMemoryMutex-<identifier>
• /dev/shmem/RTIOsapiSharedMemorySegment-<identifier>