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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
High Availability Framework Developer's Guide
Client Recovery Library Reference
ha_connection_ctrl()
Control the operation of a HA-aware connection

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
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    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.
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    - Introduction
    - What's in the High Availability Framework?
    - The QNX Neutrino Approach to HA
    - Using the High Availability Manager
    - Using the Client Recovery Library
    - HAM API Reference
    - Client Recovery Library Reference
      - ha_attach()
        Attach a recovery function to a connection to make it HA-aware
      - ha_close()
        Detach an attached HA file descriptor, then close it
      - ha_connection_ctrl()
        Control the operation of a HA-aware connection
      - ha_ConnectAttach(), ha_ConnectAttach_r()
        Create a connection and attach it to the HA lib
      - ha_ConnectDetach(), ha_ConnectDetach_r()
        Detach an attached file descriptor, then close the connection
      - ha_creat(), ha_creat64()
        Create a connection and attach it to the HA lib
      - ha_detach()
        Detach a previously attached connection
      - ha_dup()
        Duplicate an HA connection
      - ha_fclose()
        Detach an attached HA file descriptor for a file stream, then close it
      - ha_fopen()
        Open a file stream and attach it to the HA lib
      - ha_open(), ha_open64()
        Open a connection and attach it to the HA lib
      - ha_ReConnectAttach()
        Reopen a connection while performing recovery
      - ha_reopen()
        Reopen a connection while performing recovery
    - Examples
    - Glossary
  - 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.
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    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.
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    The System Architecture guide accompanies the QNX Neutrino RTOS and is intended for both application developers and end-users.
  - Technotes
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    The QNX Neutrino User's Guide is intended for all users of a QNX Neutrino RTOS system, from system administrators to end users.
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- 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
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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.

ha_connection_ctrl()

Control the operation of a HA-aware connection

Synopsis:

#include <ha/cover.h>
int ha_connection_ctrl( int coid,
                        int command,
                        void *args );

Library:

libha

Description:

The ha_connection_ctrl() function can be used to control the operation of the HA-aware conenction. Specifically it can be used to control the recovery method, temporarily suspend recovery and also control the number of times that will be attempted both consecutively for a single failure, or across all failures. Currently the following commands are defined:

HA_RECOVERY_ACOUNT: This sets the maximum number of times recovery is performed for this connection. The value is specified by passing it via args as an integer. A negative value implies that there is no limit on the number of times recovery will be performed, and this is the default state of the connection when it is made HA aware.
HA_RECOVERY_ICOUNT: This sets the maximum number of iterations, recovery is performed for this connection, each time a connection is found to have failed. This count is reset each time the connection is successfully recovered. The value is specified by passing it via args as an integer. A negative value implies that there is no limit on the number of times recovery will be performed, and this is the default state of the connection when it is made HA aware.
HA_RECOVERY_SUSPEND: Temporarily suspends any recovery on this connection. It will behave like a normal connection.
HA_RECOVERY_ENABLE: Re-enables any recovery on this connection. All other recovery options are unaffected. This just toggles the recovery enabled/disabled bit.
HA_RECOVERY_RESET_ICOUNT: Resets the iteration count used by HA_RECOVERY_ICOUNT above. This sets the internal count per iteration to zero.
HA_RECOVERY_RESET_ACOUNT: Resets the total count used by HA_RECOVERY_ACOUNT above. This sets the internal count of recoveries to zero.

Returns:

0: Success.
-1: An error occurred (errno is set).

Errors:

EBADF: No connection is specified by this coid, or connection is not HA-aware.
EINVAL: Invalid command.

Classification:


Safety:
Cancellation point	No
Interrupt handler	No
Signal handler	No
Thread	Yes

Page updated: March 12, 2026