×

Resumption of preempted non-privileged threads with no kernel intervention

  • US 5,872,963 A
  • Filed: 02/18/1997
  • Issued: 02/16/1999
  • Est. Priority Date: 02/18/1997
  • Status: Expired due to Term
First Claim
Patent Images

1. In a computer system having a processor and a memory, wherein the processor operates within both a user mode and a protected kernel mode and includes a program counter and a plurality N of registers, wherein the N registers include a first register, a method of remaining in user mode while switching between a first execution entity and a second execution entity, wherein the second execution entity has a user state defined by a program counter value, a context identifier value and N register values, the method comprising the steps of:

  • providing an instruction set capable of executing a register load instruction during execution of a jump instruction;

    while remaining in user mode, writing the user state of the first execution entity to memory; and

    while remaining in user mode, restoring the user state of the second execution entity, wherein the step of restoring the user state of the second execution entity includes the steps of;

    writing register values associated with the second execution entity to all but the first register;

    writing the context identifier value to a context identifier location;

    writing the program counter value to the first register; and

    jumping to the program counter value stored in the first register, wherein the step of jumping includes loading a last remaining register value associated with the second execution entity to the first register while jumping to said program counter value.

View all claims
  • 7 Assignments
Timeline View
Assignment View
    ×
    ×