Resource sharing between real-time and general purpose programs

A computer program product for sharing resources within a data processing system by ensuring that non-preemptable internally-triggered system resources are available to a real-time program when needed, wherein said data processing system includes;

• at least a processor;
• at least one non-preemptable internally-triggered system resource, wherein each of said resources is controlled by at least one associated device driver and has a known maximum operation time;
• at least one general purpose program which operates on a non-real-time basis;
• at least one real-time program which operates on a real-time basis and has control of said processor for a selected real-time portion of a cycle of operation;
• and at least one scheduler which manages control of resources between said real-time and general purpose programs, said computer program product comprising:
• a computer-readable storage medium having computer-readable code means embodied in said medium, said computer-readable code means comprising:
• computer readable program code means for determining a selected one of said at least one real-time programs, wherein said selected real-time program will have control of said processor at a next of said real-time portions of a cycle of operation;
• computer readable program code means for determining a set of one or more of said non-preemptable internally-triggered system resources, said set comprising those resources which said selected real-time program anticipates using;
• computer readable program code means for determining a lookahead interval for each resource in said set;
• and
• computer readable program code means for signaling said associated device driver for each resource in said set, said signal directing said device driver to stop accepting requests from said general purpose programs while said general purpose programs continue to execute, wherein said signaling is performed at a point in time before said next real-time portion of a cycle begins, said point in time being equal to said lookahead interval for said resource.

A system for sharing resources within a data processing system by ensuring that non-preemptable internally-triggered system resources are available to a real-time program when needed, wherein said data processing system includes;

• at least a processor;
• at least one non-preemptable internally-triggered system resource, wherein each of said resources is controlled by at least one associated device driver and has a known maximum operation time;
• at least one general purpose program which operates on a non-real-time basis;
• at least one real-time program which operates on a real-time basis and has control of said processor for a selected real-time portion of a cycle of operation;
• and at least one scheduler which manages control of resources between said real-time and general purpose programs, said system comprising:
• means for determining a selected one of said at least one real-time programs, wherein said selected real-time program will have control of said processor at a next of said real-time portions of a cycle of operation;
• means for determining a set of one or more of said non-preemptable internally-triggered system resources, said set comprising those resources which said selected real-time program anticipates using;
• means for determining a lookahead interval for each resource in said set;
• and
• means for signaling said associated device driver for each resource in said set, said signal directing said device driver to stop accepting requests from said general purpose programs while said general purpose programs continue to execute, wherein said signaling is performed at a point in time before said next real-time portion of a cycle begins, said point in time being equal to said lookahead interval for said resource.