Abstract: Aligning execution point of duplicate copies of a user program by exchanging information about instructions executed. At least some of the exemplary embodiments may be a method of operating duplicate copies of a user program in a first and second processor, allowing at least one of the user programs to execute until retired instruction counter values in each processor are substantially the same, and then executing a number of instructions of each user program. Of the instructions executed, at least some of the instructions are decoded and the inputs of each decoded instruction determined (the decoding substantially simultaneously with executing in each processor).

Abstract: A method and apparatus to insert special instruction. At least one of the illustrative embodiments is a method comprising converting a first representation of a computer program to a second representation, and inserting into the second representation a special instruction not needed to implement functionality in the first representation. The special instruction gives duplicate copies of the computer program executed in different processors an opportunity to service external asynchronous interrupts.

Abstract: Aligning execution point of duplicate copies of a user program by exchanging information about instructions executed. At least some of the exemplary embodiments may be a method of operating duplicate copies of a user program in a first and second processor, allowing at least one of the user programs to execute until retired instruction counter values in each processor are substantially the same, and then executing a number of instructions of each user program. Of the instructions executed, at least some of the instructions are decoded and the inputs of each decoded instruction determined (the decoding substantially simultaneously with executing in each processor).

Abstract: A method and system of aligning execution point of duplicate copies of a user program by exchanging information about instructions executed. At least some of the exemplary embodiments may be a method comprising operating duplicate copies of a user program in a first and second processor, allowing at least one of the user programs to execute until retired instruction counter values in each processor are substantially the same, and then executing a number of instructions of each user program. Of the instructions executed, at least some of the instructions are decoded and the inputs of each decoded instruction determined (the decoding substantially simultaneously with executing in each processor).

Abstract: A method and system of aligning execution point of duplicate copies of a user program by copying memory stores. Some of the exemplary embodiments may be a method comprising aligning the execution point of duplicate copies of a user program executed in a first and second processor by copying only data of memory stores performed by the user program in the first processor from a memory of the first processor to a memory of the second processor, and copying the register state of the user program from the first processor for use by the second processor.

Abstract: A method and system of aligning execution point of duplicate copies of a user program by exchanging information about instructions executed. At least some of the exemplary embodiments may be a method comprising operating duplicate copies of a user program in a first and second processor, allowing at least one of the user programs to execute until retired instruction counter values in each processor are substantially the same, and then executing a number of instructions of each user program. Of the instructions executed, at least some of the instructions are decoded and the inputs of each decoded instruction determined (the decoding substantially simultaneously with executing in each processor).

Abstract: A method and system of aligning execution point of duplicate copies of a user program by copying memory stores. Some of the exemplary embodiments may be a method comprising aligning the execution point of duplicate copies of a user program executed in a first and second processor by copying only data of memory stores performed by the user program in the first processor from a memory of the first processor to a memory of the second processor, and copying the register state of the user program from the first processor for use by the second processor.

Abstract: A system and method that implement a strategy for automatically generating self-checking tests of source-to-source translation. The tests make certain that software components produced by a source-to-source computer language translator continue to be binary-compatible with all other software components with which they previously interacted correctly, including components that remain in the original programming language. To that end, the correctness of procedure interfaces in a target computer program is also verified. With this strategy, correct translation of text preprocessor mechanisms such as macros, conditionally compiled regions of code, and source file inclusion can be achieved. The target program is the result of translating a source program written in a different language from the target program. The system creates a set of procedure calls to each procedure in the source program. The system also creates a set of callable procedures with the same interface specification as in the source program.

Abstract: A system for identifying the file structure of a computer program, preserving the file structure of the code after translation of source code from one high-level computer language to another, combining pieces of a source file that were generated in different translation sessions, and ensuring textual consistency of each piece of generated code in the resultant code files.

Abstract: A method, system, apparatus, and program for translating one computer language to another using doubly-rooted tree data structures. A doubly-rooted tree is the combination of two sets of hierarchically related objects sharing a common set of leaves. An N-rooted tree is also described. When a doubly-rooted tree is constructed in the specified manner and then translated to a second doubly-rooted tree, source language code is transformed into target language code. In addition, the translation preserves preprocessor characteristics of the source language code including macros, conditionally compiled regions of code, source inclusion statements, and comments.

Abstract: A method and apparatus for translating source code written in one computer language to source code written in another language wherein translated static fragments are generated in the face of textual inconsistencies. Exactly one target language definition of each source language static fragment is generated and the differences are encapsulated in new parameters.

Abstract: A method and apparatus for translating source code written in one computer language to source code written in another language wherein translated static fragments are generated in the face of textual inconsistencies. Exactly one target language definition of each source language static fragment is generated and the differences are encapsulated in new parameters.

Abstract: A method, system, apparatus, and program for translating one computer language to another using doubly-rooted tree data structures. A doubly-rooted tree is the combination of two sets of hierarchically related objects sharing a common set of leaves. An N-rooted tree is also described. When a doubly-rooted tree is constructed in the specified manner and then translated to a second doubly-rooted tree, source language code is transformed into target language code. In addition, the translation preserves preprocessor characteristics of the source language code including macros, conditionally compiled regions of code, source inclusion statements, and comments.

Abstract: A system and method for automatically checkpointing a primary computer process to a backup computer process is disclosed. The system and method automatically convert a non-fault tolerant computer program into a fault tolerant computer program. The system includes multiple CPUs, a communications link between the CPUs and a user interface device, such as a terminal, workstation, or PC. A special layer of code forms an interface between the operating system for each CPU and the application programs running on the CPUs. For each process, running on one of the CPUs, the interface automatically creates a duplicate backup process on another CPU. The interface handles synchronizing communications between the original or primary process and the backup process, and suppresses or otherwise prevents or inhibits output from the backup process.