Sun Java System Message Queue 4.3 Developer's Guide for C Clients

Building and Running C Clients

Message Queue provides several sample Message Queue C-client applications that illustrate how to send and receive messages. Before you run these applications, read through the next two sections to make sure that you understand the general procedure and requirements for building and running Message Queue C-Client programs.

Building C Clients

This section explains how you build Message Queue programs from C source files. You should already be familiar with writing and compiling C applications.

Header Files and Shared Libraries

The Message Queue C client includes the header files (mqcrt.h), the C client runtime shared library mqcrt, and its direct dependency libraries. When writing a Message Queue C client application, you should include the header files and link to the runtime library mqcrt.

For each platform, the next table lists the installed location of the header files and the supporting runtime library.

Table 1–1 Locations of C-API Libraries and Header Files



Header File 


/opt/SUNWimq/lib (32–bit)

/opt/SUNWimq/lib/amd64 (64–bit)



/opt/SUNWimq/lib (32–bit)

/opt/SUNWimq/lib/sparcv9 (64–bit)











Pre-Processor Definitions

Use the appropriate compiler for your platform, as described in the Sun Java System Message Queue 4.3 Release Notes.

When compiling a Message Queue C client application, you need to specify the pre-processor definition shown for each platform in Table 1–2. This definition is used to support Message Queue fixed-size integer types.

Table 1–2 Preprocessor Definitions for Supporting Fixed-Size Integer Types











C++ Runtime Library Support

When building a Message Queue C client application, you should be aware that the Message Queue C runtime library is a multi-threaded library and requires C++ runtime library support:

Providing Runtime Support

To run a Message Queue C-client application, you need to make sure that the application can find the mqcrt shared library. Please consult the documentation for your compiler to determine the best way to do this.

You also need to make sure that the appropriate C++ runtime support library, as described in C++ Runtime Library Support is available.

On Windows you also need to make sure that your application can find the dependent libraries NSPR and NSS that are shipped with Message Queue. These may be different from the NSPR and NSS libraries that are installed on your system to support the Netscape browser and the Sun Java System Application Server. The mqcrt shared library depends directly on the NSPR and NSS versions installed with Message Queue. If a different version of the libraries is loaded at runtime, you may get a runtime error specifying that the libraries being used are incompatible. If this happens, look on your system to see if other versions of the NSPR or NSS libraries exist; for example, libnspr4.dll or nss3.dll. If you find such versions, take appropriate action to make sure that Message Queue can access the versions it needs.