US 6,481,007 B1 · Optimizing parameter passing

Abstract

A method and system for optimizing the passing of a parameter to a routine is provided. It is determined if any parameters are aliased in a call to a called routine. In the absence of aliases, calling routines passing parameters to called routines using “call by reference”. Recovery mechanisms are provided, when appropriate, when unhandled exception occur during execution of the called routines. According to the method, a recovery mechanism includes encapsulating the called routine and call statement block with a “catch-all” exception handler. The response to an otherwise unhandled exception includes restoring the actual parameter using a stored copy of the actual parameter. The restoration is performed by making a handle point to the copy of the actual parameter that was made before execution of the called routine.

Claims33

Dependent claims

A method for executing a call that includes passing a parameter from a calling routine to a called routine, the method comprising the steps of:

determining whether the parameter is aliased;
if the parameter is not aliased, then
generating code to pass the parameter using call by reference;
if the parameter is aliased, then generating code to pass the parameter in the call using call by value.

1 more element

A computer-readable medium carrying one or more sequences of instructions for executing a call that includes passing a parameter from a calling routine to a called routine, wherein execution of the one or more sequences of instructions by one or more processors causes the one or more processors to performs the steps of:

making a copy of a value of the parameter;
passing the parameter from the calling routine to the called routine using call by reference;
detecting if there is an unhandled exception during execution of the called routine;
if an unhandled exception occurs during execution of the called routine, then restoring the parameter;
and
if an unhandled exception does not occur during execution of the called routine, then
exiting the called routine without restoring the parameter.

4 more elements

A computer system for executing a call that includes passing a parameter from a calling routine to a called routine, the computer system comprising a memory containing one or more sequences of instructions which, when executed by one or more processors, cause the one or more processors to perform the steps of:

determining whether the parameter is aliased;
if the parameter is not aliased, then
generating code to pass the parameter using call by reference;
and
if the parameter is alaised, then generating code to pass the parameter in the call using call by value.

2 more elements

receiving the call from the calling routine in which a parameter is passed to the called routine;
making a copy of a value of the parameter;
passing the parameter from the calling routine to the called routine using call by reference;
detecting if there is an unhandled exception during execution of the called routine;
if an unhandled exception occurs during execution of the called routine, then
restoring the parameter;
and
if an unhandled exception does not occur during execution of the called routine, then
exiting the called routine without restoring the parameter.

6 more elements

Dependencies are inferred from the claim text.

Optimizing parameter passing

Life of this patent

Optimizing parameter passing

Life of this patent

Abstract

Claims33