Method and Apparatus for Non-Deterministic Incremental Program Replay Using Checkpoints and Syndrome Tracking

A system for replaying a program, comprising:

• a memory;
• and
• at least one processor, coupled to the memory, operative to:
• record for a given execution of said program:
• one or more checkpoints of said program, said one or more checkpoints containing program state information;
• and
• a recorded list of value changes for one or more identified variables executing in one or more threads of said program;
• and
• during a replay execution of said program:
• commence execution from a particular one of said recorded checkpoints;
• restore said program state information associated with said particular one of said recorded checkpoints;
• compare an observed list of values to said recorded list of values for said one or more identified variables executing in each of said one or more threads;
• and
• identify a difference between said observed list of values and said recorded list of values.

An article of manufacture for replaying a program, comprising a machine readable medium containing one or more programs which when executed implement the steps of:

• recording for a given execution of said program:
• one or more checkpoints of said program, said one or more checkpoints containing program state information;
• and
• a recorded list of values for one or more identified variables executing in one or more threads of said program;
• and
• during a replay execution of said program:
• commencing execution from a particular one of said recorded checkpoints;
• restoring said program state information associated with said particular one of said recorded checkpoints;
• comparing an observed list of values to said recorded list of values for said one or more identified variables executing in each of said one or more threads;
• and
• identifying a difference between said observed list of values and said recorded list of values.