Programming Conventions

The ChorusOS operating system provides a large variety of services that you can use in your applications. These services are accessed as C routines. C header files provide the required constants, types, and prototype definitions. The high modularity of the ChorusOS operating system is reflected by the numerous header files. However, in the following examples a global header file, named chorus.h, is used for simplicity. The chorus.h header file collects most of the required header files. Refer to the man pages to obtain the actual minimum header files required for each service.

Most ChorusOS operating system constants are prefixed with K_. ChorusOS operating system error codes are prefixed with with K_E.

Constants and error codes are all written in uppercase.

Most specific data types are prefixed by Kn. When type names are composed of several lexemes, the first letter of each lexeme is written in uppercase while the remaining letters are in lowercase, as in KnRgnDesc (region descriptor).

To compile and link an application, the following information must be specified in the makefile:

• The header file directories and compilation flags.

• The program entry point.

• The libraries to be linked to the program according to the services used by the:

  • Application

  • Environment present on the target system

  • Actor type (user or supervisor)