Method and apparatus for scheduling multiple threads for execution in a shared microprocessor pipeline

A method for scheduling multiple threads for execution on a shared processor pipeline, comprising:

• maintaining at least one thread status register to keep track of thread states for each of a plurality of threads, said thread states comprising a ready state, a run state and at least one wait state;
• maintaining a thread order register for the plurality of threads to track a thread execution order defining which thread was least recently executed;
• scheduling any one or more of the plurality of threads for execution that are in the ready state or the run state by assigning a higher priority to a thread that is in a ready state and a lower priority to a thread that is in a run state, with priority between any two or more threads in a ready state being given to whichever thread was least recently executed.

An article of manufacture having at least one recordable medium having stored thereon one or more executable instructions which, when executed by at least one shared processing device, cause the at least one processing device to schedule execution of multiple threads on said processing device by:

• tracking a thread state for each of a plurality of threads, where said thread state may comprise a ready state, a speculative ready state, a run state and a speculative run state;
• scheduling for execution any one or more of the plurality of threads by assigning a higher priority to a thread that is in a ready state, a lower priority to a thread that is in a speculative ready state, and a lowest priority to a thread that is in either a run state or a speculative run state, with priority between any two or more threads in a ready state or in the speculative ready state being given to whichever thread was least recently executed.