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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 QNX Neutrino 7.1.
OS Components & Operations
Platform-independent Publish/Subscribe Developer's Guide
This guide is intended for application developers who want to use the Platform-independent Publish Subscribe (PiPS) framework to exchange information with other applications. First, the overall PiPS design and data-exchange model are explained. Then, tutorials on using PiPS are given. These tutorials cover key tasks such as selecting a publish-subscribe provider to use and writing plugins that read and write custom data types.
PiPS Client API
pips_multimap_t
PiPS multimap
pips_multimap_clear()
Clear the mappings in a multimap

QNX Momentics IDE User's Guide
This User's Guide describes version 7.1 of the Integrated Development Environment (IDE) that's part of the QNX Momentics 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 QNX Neutrino 7.1.
- Quickstart Guide
- OS Components & Operations
  - Adaptive Partitioning User's Guide
  - Boot Optimization Guide
    The Boot Optimization Guide describes techniques you can use to reduce the time from your board's initial power on until you have a fully functional QNX system running on the board.
  - Building Embedded Systems
    The Building Embedded Systems guide is intended for developers who are developing or building BSPs for QNX Neutrino RTOS embedded systems.
  - Core Networking Stack User's Guide
    This guide introduces you to the QNX Neutrino Core Networking stack and its manager, io-pkt.
  - Customizing a BSP
    While QNX provides Board Support Packages (BSPs) for many common platforms and their individual variants, in some cases, you need a BSP for a board that QNX does not provide. If this is the case, you can modify a QNX BSP or develop your own.
  - Device Publishers Developer's Guide
  - High Availability Framework Developer's Guide
  - High-Performance Networking Stack (io-sock) User's Guide
    This guide contains instructions for implementing and using the QNX Neutrino High-Performance Networking Stack and its manager, io-sock.
  - Instant Device Activation
  - Migrating to QNX SDP 7.1
  - PCI Server User's Guide
  - Persistent Publish/Subscribe Developer's Guide
  - Platform-independent Publish/Subscribe Developer's Guide
    This guide is intended for application developers who want to use the Platform-independent Publish Subscribe (PiPS) framework to exchange information with other applications. First, the overall PiPS design and data-exchange model are explained. Then, tutorials on using PiPS are given. These tutorials cover key tasks such as selecting a publish-subscribe provider to use and writing plugins that read and write custom data types.
    - PiPS Overview
      The Platform-independent Publish Subscribe (PiPS) framework allows applications to exchange information using publish-subscribe communication. The PiPS framework hides the details of the underlying services used for interprocess communication (IPC), by providing a common interface for sending and receiving data.
    - PiPS Configuration
      PiPS is configured through JSON files that specify which providers to load, the library files that implement data types, and the available topics and their properties such as Quality of Service (QOS). Depending on your setup, you may have a global configuration file and/or one or more files that configure individual providers.
    - Writing PiPS applications
      PiPS exposes a C API that lets client applications first select which publish-subscribe providers to use and then, within these providers, create topics and publications to exchange data.
    - Writing an RTPS type plugin
      The Fast RTPS provider defines routines for encoding and decoding basic data types as they're written or read through the Fast RTPS service. Sometimes, these built-in types might not meet your application needs. For these scenarios, the provider supports pluggable type definitions, which let you define custom data types and load them into the runtime environment.
    - PiPS Client API
      - Definitions and constants in PiPS Client API
      - pips_data_t
        Buffer type for publication data
      - pips_enable_debug()
        Enable or disable debug logging by PiPS
      - pips_enable_trace()
        Enable or disable system tracing by PiPS
      - pips_encoding_e
        Supported encoding types
      - pips_entity_t
        Handle to a PiPS entity
      - pips_event_handler_t
        Union of event-handler function types
      - pips_group_t
        Handle to a group topic
      - pips_group_member_t
        Handle to a PiPS group member
      - pips_guid_t
        GUID of a PiPS publisher/subscriber
      - pips_guid_str_t
        String representation of a GUID
      - pips_multimap_t
        PiPS multimap
        pips_multimap_add_blob()
        Map a key to a BLOB value
        pips_multimap_add_boolean()
        Map a key to a boolean value
        pips_multimap_add_json()
        Map a key to a JSON object
        pips_multimap_add_number()
        Map a key to a numeric value
        pips_multimap_add_string()
        Map a key to a string value
        pips_multimap_clear()
        Clear the mappings in a multimap
        pips_multimap_dup_string()
        Express the current multimap as a string
        pips_multimap_get_item()
        Get a named item from a multimap
        pips_multimap_item_t
        Single mapping in a multimap
        pips_multimap_set_value()
        Set a value in the current multimap
        pips_multimap_type_e
        Multimap value types
        pips_multimap_value_t
        Union of all possible multimap value types
      - pips_namespace_t
        Handle to a namespace
      - pips_provider_t
        PiPS provider instance
      - pips_publication_t
        Handle to a topic publication
      - pips_set_verbosity()
        Set the PiPS verbosity for the general system log
      - pips_topic_t
        Handle to a topic
  - QDB Developer's Guide
  - QNX Helpers Developer's Guide
    These libraries provide QNX helpers, including helpers that assist with logging, string conversion, and number and type sizes.
  - SMMUMAN User's Guide
  - System Analysis Toolkit (SAT) User's Guide
  - System Architecture
    The System Architecture guide accompanies the QNX Neutrino RTOS and is intended for both application developers and end-users.
  - Technotes
  - User's Guide
    The QNX Neutrino User's Guide is intended for all users of a QNX Neutrino RTOS system, from system administrators to end users.
- Audio & Graphics API
- Multimedia
- Networking Middleware
- Programming
- Sensor Framework
- System Security Guide
  The QNX System Security Guide is intended for both system integrators who are responsible for the security of a QNX Neutrino RTOS system and developers who want to create a QNX Neutrino resource manager free from vulnerabilities.
- Utilities & Libraries
QNX Hypervisor
The QNX Hypervisor allows you to run multiple OSs on a target system so you can separate critical and non-critical functions, support a wide variety of applications, and reduce hardware costs.
QNX Software in the Cloud
QNX Software in the Cloud enables developers to use the QNX software in Amazon Web Services (AWS) and Microsoft Azure (Azure).
QNX Advanced Virtualization Frameworks User's Guide
This User's Guide is aimed at all systems integrators and developers who want to design and build embedded systems using the QNX Advanced Virtualization Frameworks.
Typographical Conventions, Support, and Licensing
This section describes the typographical conventions used throughout the documentation and explains how to obtain technical support.

pips_multimap_clear()

Clear the mappings in a multimap

Synopsis:

#include <pips/multimap.h>

int pips_multimap_clear(pips_multimap_t *multimap)

Arguments:

multimap: A pointer to the pips_multimap_t instance whose mappings are being cleared

Library:

pips-client

Description:

This function deletes all items in the current pips_multimap_t instance, effectively removing all of the key-value mappings. This function must be used to safely delete the contents of a multimap; otherwise, memory may be leaked.

Returns:

0: The multimap was cleared successfully

-1: An error prevented the multimap from being cleared (errno is set)

Errors:

EINVAL: The multimap instance is not valid.

Page updated: March 12, 2026