IEEE 1003.1d:1999

Amendment Standard - Superseded.
This standard is part of the POSIX series of standards for applications and user inter-faces to open systems. It defines the applications interface to system services for spawning a process, timeouts for blocking services, sporadic server scheduling, execution time clocks andtimers, and advisory information for file management. This standard is stated in terms of its Cbinding.

This work activity will extend the system interfaces defined by 1003.1 (as amended by 1003.1b, 1003.1c, and 1003.1i) to include the following additional facilities required by realtime applications: an efficient process creation mechanism, additional realtime scheduling policies, interfaces for execution time monitoring, interfaces for interacting with special devices, interfaces for improving I/O performance, and timeouts for blocking functions. This standard will not change the base standard which it amends (including any existing amendments) in such a way as to cause implementations or strictly conforming applications to no longer conform.
A strong need exists to extend the POSIX interfaces to provide more complete realtime functions. The existing interfaces of POSIX when including the 1003.1b and 1003.1c extensions, provide the base functions to support the portability of applications with realtime requirements. Examples of needed extensions are additional realtime scheduling policies such as deadline, an interface to allow the solution of the priority inversion problem of existing synchronization mechanisms, possible additional synchronization mechanisms, and address the issue of portability at the device driver interface.