Method apparatus for implementing multiple return sites

A computer-implemented method for storing data associated with one of a plurality of return points to enable the data associated with the one of the plurality of return points to be efficiently obtained, the plurality of return points including an expected return point and at least a first alternate return point, the computer-implemented method comprising:

• executing a routine, the routine being arranged to call a function which is not a part of the routine;
• calling the function from within the routine while the routine is executing;
• beginning an execution of the function;
• returning from the function to the routine, wherein the function accesses a first instruction in the routine, the first instruction in the routine being located substantially at the expected return point, the first instruction including data associated with the one of the plurality of return points;
• executing the first instruction in the routine when the function returns as expected, wherein executing the first instruction uses insignificant computational overhead and does not affect execution of the routine;
• accessing an embedded library value associated with the first instruction to calculate the first alternate return point when the function does not return as expected and returns as a first unexpected return;
• and
• executing a second instruction in the routine at the first alternate return point when the function does not return as expected and returns as the first unexpected return, wherein when the function does not return as expected and returns as the first unexpected return, the first instruction is not executed.

A computer program product for storing data associated with one of a plurality of return points to enable the data associated with the one of the plurality of return points to be efficiently obtained, the plurality of return points including an expected return point and at least a first alternate return point, the computer program product comprising:

• computer code for executing a routine, the routine being arranged to call a function which is not a part of the routine;
• computer code for calling the function from within the routine while the routine is executing;
• computer code for beginning an execution of the function;
• computer code for returning from the function to the routine, wherein the function accesses a first instruction in the routine, the first instruction in the routine being located substantially at the expected return point, the first instruction including data associated with the one of the plurality of return points;
• computer code for executing the first instruction in the routine when the function returns as expected, wherein executing the first instruction uses insignificant computational overhead and does not affect execution of the routine;
• computer code for accessing an embedded library value associated with the first instruction to determine the first alternate return point when the function does not return as expected and returns as a first unexpected return;
• computer code for executing a second instruction in the routine at the first alternate return point when the function does not return as expected and returns as the first unexpected return, wherein when the function does not return as expected and returns as the first unexpected return, the first instruction is not executed;
• and
• a computer-readable medium that stores the computer codes.

A computer program product for using a dummy instruction associated with a return point containing an embedded library value to identify one of a plurality of return points including an expected return point and an alternate return point, the computer program product comprising:

• computer code for calling a function from within a routine while the routine is executing, wherein the function is external to the routine;
• computer code for beginning an execution of the function;
• computer code for returning to the routine from the execution of the called function at a return point associated with the dummy instruction;
• when the execution of the called function returns normally such that the return point is an expected return point, then
• executing the dummy instruction using essentially no overhead;
• when the execution of the called function requires an alternate return such that the return point is an alternate return point, then
• reading the embedded library value;
• determining the alternate return point based only upon the embedded library value;
• computer code for executing an instruction in the routine at the return point;
• and
• a computer-readable medium that stores the computer codes.