Condition handling in a multi-language computer program

A method for handling conditions in a computer system, the conditions occurring during execution of a program including routines prepared in a plurality of computer programming languages (a multi-language thread), comprising the steps of:

• (a) initializing a condition processing means to turn over control of the computer system to a means for managing cooperatively condition handlers for said multi-language thread while preserving a language semantic of an executing routine, procedure, or function (a Common Condition Handler (CCH) when a condition occurs;
• (b) queuing a plurality of language specific condition handlers (LSH) as a program routines are initialized, each LSH being associated with a separate stack frame of each separate program routine and corresponding to the language in which the separate program routine is written;
• (c) queuing one or more user condition handler routines (User Handlers) as requested by the program with each being associated with a stack frame;
• (d) detecting occurrence of a condition and determining a current stack frame, then executing a last queued LSH for the current stack frame to determine whether the condition is enabled and resuming execution of the program if the condition is not enabled;
• (e) executing the User Handlers for the current stack frame in queue order beginning with the last queued User Handler until one of the User Handlers indicates that the condition has been handled or until the queue is empty;
• (f) executing the last queued LSH for the current stack frame to handle the condition if none of the User Handlers handled the condition;
• (g) applying semantics of the high level language of the routine, procedure or function where the condition occurred to handle the condition if the condition needs to be handled after each queue of User Handlers and each queued LSH associated with the stack had an opportunity to handle the condition;
• (h) accepting return information from one or more of the Handlers requesting that the condition be redefined as a second condition (Promote Request);
• and
• (i) processing the Promote Request by executing a Handler and passing the second condition to the Handler.

A method for handling conditions in a computer system, the conditions occurring during execution of a program including routines prepared in a plurality of computer programming languages (a multi-language thread), comprising the steps of:

• (a) initializing a condition processing means to turn over control of the computer system to a means for managing cooperatively condition handlers for said multi-language thread while preserving a language semantic of an executing routine, procedure, or function (a Common Condition Handler (CCH) when a condition occurs;
• (b) queuing a plurality of language specific condition handlers (LSH) as a program routines are initialized, each LSH being associated with a separate stack frame of each separate program routine and corresponding to the language in which the separate program routine is written;
• (c) queuing one or more user condition handler routines (User Handlers) as requested by the program with each being associated with a stack frame;
• (d) detecting occurrence of a condition and determining a current stack frame, then executing a last queued LSH for the current stack frame to determine whether the condition is enabled and resuming execution of the program if the condition is not enabled;
• (e) executing the User Handlers for the current stack frame in queue order beginning with the last queued User Handler until one of the User Handlers indicates that the condition has been handled or until the queue is empty;
• (f) executing the last queued LSH for the current stack frame to handle the condition if none of the User Handlers handled the condition;
• (g) applying semantics of the high level language of the routine, procedure or function where the condition occurred to handle the condition if the condition needs to be handled after each queue of User Handlers and each queued LSH associated with the stack had an opportunity to handle the condition;
• (h) saving a Resume Cursor when the condition occurs;
• (i) accepting return information when a Handler to the CCH requesting that the Resume Cursor be changed to a new value;
• (j) changing the Resume Cursor to the new value;
• and
• (k) transferring control to the instruction pointed to by the Resume Cursor.

A method for operating a compiler for a computer programming language which creates object code for programs in a computer system using multiple computer programming languages (a multi-language thread) comprising the steps of:

• (a) creating initialization object code which branches to an external entry point of a means for managing cooperatively condition handlers for the multi-language thread while preserving a language semantic of an executing routine, procedure, or function (a Common Condition Handler (CCH) to identify a language specific condition handler (LSH);
• (b) preparing object code for an LSH which when called by the CCH for a condition will:
• (1) accept a parameter having at least a first and second values;
• (2) return information to the CCH when the parameter equals the first value which indicates whether the condition is enabled;
• (3) handle selected conditions related to the computer programming language when the parameter equals the second value and return information to the CCH which indicates whether the condition is handled (Resume Request), whether the condition should be changed to a new value (Promote Request), and whether the condition should be passed to another condition handler (Percolate Request);
• and
• (c) storing the object code in a persistent memory for subsequent execution as a part of a program.

A computer system using multiple computer programming languages (a multi-language thread) comprising:

• (a) means for managing cooperatively condition handlers for said multi-language thread while preserving a language semantic of an executing routine, procedure or function (a Common Condition Handler (CCH));
• (b) means for linking object code from source code including routines prepared in one or more computer programming languages with the CCH to produce an executable program;
• (c) means for executing the program;
• (d) means for initializing a condition processing means to turn over control of the computer system to the CCH when a condition occurs;
• (e) means for queuing one or more language specific condition Handler (LSH) as routines are initialized, each routine having one LSH, which corresponds to the language in which the routine is written and which is associated with a stack frame;
• (f) means for queuing one or more user condition handling routines (User Handler) as requested by the program with each being associated with a stack frame;
• (g) means for detecting the occurrence of a condition and determining a current stack frame, and for executing a last queued LSH for the current stack frame to determine whether the condition is enabled and resuming executing of the program if the condition is not enabled;
• (h) means for executing the User Handlers for the current stack frame in queue order beginning with the last queued User Handler until one of the User Handlers indicates that the condition has been handled or until the queue is empty;
• (i) means for executing the last queued LSH for the current stack frame to handle the condition if none of the User Handlers handled the condition;
• and
• (j) means for applying semantics of the high level language of the routine, procedure or function where the condition occurred to handle the condition if the condition needs to be handled after each queue of User Handlers and each queued LSH associated with the stack had an opportunity to handle the condition.

A computer system using multiple computer programming languages (a multi-language thread) comprising:

• (a) means for managing cooperatively condition handlers for said multi-language thread while preserving a language semantic of an executing routine, procedure or function (a Common Condition Handler (CCH));
• (b) means for linking object code from source code including routines prepared in one or more computer programming languages with the CCH to produce an executable program;
• (c) means for executing the program;
• (d) means for initializing a condition processing means to turn over control of the computer system to the CCH when a condition occurs;
• (e) means for queuing one or more language specific condition Handler (LSH) as routines are initialized, each routine having one LSH, which corresponds to the language in which the routine is written and which is associated with a stack frame of the routine;
• (f) means for queuing one or more user condition handling routines (User Handler) as requested by the program with each being associated with a stack frame;
• (g) means for detecting the occurrence of a condition and determining a current stack frame, and for executing a last queued LSH for the current stack frame to determine whether the condition is enabled and resuming executing of the program if the condition is not enabled;
• (h) means for executing the User Handlers for the current stack frame in queue order beginning with the last queued User Handler until one of the User Handlers indicates that the condition has been handled or until the queue is empty;
• (i) means for executing the last queued LSH for the current stack frame to handle the condition if none of the User Handlers handled the condition;
• (j) means for applying semantics of the high level language of the routine, procedure or function where the condition occurred to handle the condition if the condition needs to be handled after each queue of User Handlers and each queued LSH associated with the stack had an opportunity to handle the condition;
• (k) means for accepting return information from one or more of the Handlers requesting that the condition be redefined as a second condition (Promote Request);
• and
• (l) means for processing the Promote Request by executing a Handler and passing the second condition to the Handler.

A computer system using multiple computer programming languages (a multi-language thread) comprising:

• (a) means for managing cooperatively condition handlers for said multi-language thread while preserving a language semantic of an executing routine, procedure or function (a Common Condition Handler (CCH));
• (b) means for linking object code from source code including routines prepared in one or more computer programming languages with the CCH to produce an executable program;
• (c) means for executing the program;
• (d) means for initializing a condition processing means to turn over control of the computer system to the CCH when a condition occurs;
• (e) means for queuing one or more language specific condition Handler (LSH) as routines are initialized, each routine having one LSH, which corresponds to the language in which the routine is written and which is associated with a stack frame of the routine;
• (f) means for queuing one or more user condition handling routines (User Handler) as requested by the program with each being associated with a stack frame;
• (g) means for detecting the occurrence of a condition and determining a current stack frame, and for executing a last queued LSH for the current stack frame to determine whether the condition is enabled and resuming executing of the program if the condition is not enabled;
• (h) means for executing the User Handlers for the current stack frame in queue order beginning with the last queued User Handler until one of the User Handlers indicates that the condition has been handled or until the queue is empty;
• (i) means for executing the last queued LSH for the current stack frame to handle the condition if none of the User Handlers handled the condition;
• (j) means for applying semantics of the high level language of the routine, procedure or function where the condition occurred to handle the condition if the condition needs to be handled after each queue of User Handlers and each queued LSH associated with the stack had an opportunity to handle the condition;
• (k) means for saving a Resume Cursor when a condition occurs;
• (l) means for accepting return information from a Handler to the CCH requesting that the Resume Cursor be changed to a new value;
• (m) means for changing the Resume Cursor to the new value;
• and
• (n) means for transferring control to the instruction pointed to by the Resume Cursor.

A system for compiling a computer programming language which creates object code for programs which use a means for managing cooperatively condition handlers for routines prepared in a plurality of computer programming languages (a multi-language thread) while preserving a language semantic of an executing routine, procedure, or function (a Common Condition Handling (CCH) in a computer system comprising:

• (a) means for creating initialization object code which branches to a CCH external entry point to identify a language specific condition handler (LSH);
• (b) means for preparing object code for an LSH capable of being called by the CCH when a condition occurs, the LSH including:
• (1) means for accepting a parameter having at least first and second values;
• (2) means for returning information to the CCH when the parameter equals the first value which indicates whether the condition is enabled;
• (3) means for handling selected conditions related to the computer programming language when the parameter equals the second value and for returning information to the CCH which indicates whether the condition is handled (Resume Request), whether the condition should be changed to a new value (Promote Request), and whether the condition should be passed to another condition handler (Percolate Request);
• and
• (c) means for storing the object code in a memory for subsequent execution as a part of a program.

A method for handling conditions in a computer system, the conditions occurring during execution of a program including routines prepared in a plurality of computer programming languages (a multi-language thread), said method comprising:

• queuing a plurality of high level language (HLL) condition handlers, each HLL condition handler being associated with a separate stack frame of each separate routine and corresponding to the high level language in which the separate routine is written;
• managing cooperatively condition handling among said handlers, where said multi-language thread includes a stack frame based conditions handling model and a global error table condition handling model, including executing the handlers in a queued order and allowing a handler to at least a) present a condition to a different handler (percolate), to b) to replace the condition with a new condition and to present the new condition to another handler (promote), or c) to handle the condition (resume);
• and
• applying semantics of the high level language of the routine where the condition occurred to handle the condition if the condition needs to be handled after each HLL condition handler associated with the stack had an opportunity to handle the condition.

A computer system comprising:

• means for handling conditions in a computer system, the conditions occurring during an execution of a program including routines prepared in a plurality of computer programming languages (a multi-language thread), where said multi-language thread includes a stack frame based condition handling model and a global error table condition handling model;
• means for queuing a plurality of high level language (HLL) condition handlers, each HLL condition handler being associated with a separate stack frame of each separate routine and corresponding to the high level language in which the separate routine is written;
• means for managing cooperatively condition handling among said handlers including executing the handlers in a queued order and allowing a handler to at least a) present a condition to a different handler (percolate), or b) to replace the condition with a new condition and to present the new condition to another handler (promote), or c) to handle the condition (resume);
• and
• means for applying semantics of the high level language of the routine where the condition occurred to handle the condition if the condition needs to be handled after each HLL condition handler associated with the stack had an opportunity to handle the condition.

An article of manufacture, for use in a computer system, comprising:

• means for causing a handling of conditions in a computer system, the conditions occurring during an execution of program including routines prepared in a plurality of computer programming languages (a multi-language thread), where said multi-language thread includes a stack frame based condition handling model and a global error table condition handling model;
• means for causing a queuing of a plurality of high level language (HLL) condition handlers, each HLL condition handler being associated with a separate stack frame of each separate routine and corresponding to the high level language in which the separate routine is written;
• means for causing a managing cooperatively of condition handling among said handlers including causing an execution of the handlers in a queued order and allowing a handler to at least a) present a condition to a different handler (percolate), or b) to replace the condition with a new condition and to present the new condition to another handler (promote), or c) to handle the condition (resume);
• and
• means for applying semantics of the high level language of the routine where the condition occurred to handle the condition if the condition needs to be handled after each HLL condition handler associated with the stack had an opportunity to handle the condition.