Safety net paradigm for managing two computer execution modes

A method of executing a program in a computer, comprising the steps of:

• executing instructions in a first interpreter for executing instructions of an instruction set, the first interpreter being less than fully correct, the execution being under a monitor capable of detecting any deviation from fully-correct interpretation before any side-effect of the incorrect interpretation is irreversibly committed;
• and
• when the monitor detects the deviation, continuing execution in a second, fully-correct interpreter, primarily in hardware, for executing instructions of the instruction set.

A computer, comprising:

• a first interpreter designed to execute a program coded in an instruction set, the first interpreter being less than fully correct;
• a second, fully-correct interpreter, primarily in hardware, for executing instructions of the instruction set;
• a monitor designed to detect any deviation from fully-correct interpretation by the first interpreter, before any side-effect of the incorrect interpretation is irreversibly committed, and when the monitor detects the deviation, to roll back execution to an instruction boundary of the instruction set, and to re-initiate execution in the second interpreter.

A method, comprising the steps of:

• translating a source program into an object program, the translated object program having a different execution behavior than the source program;
• when an interrupt occurs during execution of the object program, establishing a state of the program corresponding to a state that would have occurred during an execution of the source program, and from which execution can continue;
• executing the source program from the established state in a mode that executes or interprets the source program without re-translation into the language of the object program.

A computer, comprising:

• a binary translator programmed to translate a source program into an object program, the translated object program having a different execution behavior than the source program;
• an interrupt handler programmed to respond to an interrupt occurring during execution of the object program by establishing a state of the program corresponding to a state that would have occurred during an execution of the source program, and from which execution can continue, and to initiate execution of the source program from the established state in a mode that executes or interprets the source program without re-translation into the language of the object program.