International Business Machines Corporation

John Clarence Endicott

Steven Jay Munroe

Robert Peter Resch

Jon H Peterson

Peter Joseph Heyrman

Steven Lester Halter

Erik Edward Voldal

Richard G Mustain

Stephen A Dahl

R Karl Kirkman

Elliot Karl Kolodner

Xin Xu

Robert Carl Seemann

Daniel Rodman Hicks

OOP environments comprise composite data structures and internal mechanisms for manipulating those structures. The structures are used to allow a user to realize the power of OOP. Hence, the layout of these structures, the way in which the structures inter-relate, and the manner in which they are built and used are all critical to the utility of a particular OOP environment. It is no surprise, then, that manufacturers and suppliers of OOP environments are constantly striving to design composite data structures and internal mechanisms which maximize user productivity. The internal mechanisms and structures that make up the present invention are collectively referred to as the New Object Model (NOM). The composite data structures and organization of the NOM OOP environment provide significant benefits that are not provided by the environments of the prior art. These benefits include: a more efficient method resolution scheme and the ability to add method programs and object instance data to a class definition without the need to recompile the majority of the code base.

Efficient method router that supports multiple simultaneous object versions

The present invention utilizes a hardware Window Storage Protection Controller (WSPC) and an Object Encapsulation Enforcement Manager (OEEM) to limit access to object data to only those methods which are encapsulated by the object All of the objects of the computer system which require protection are stored in protected storage by a base storage protection mechanism so that only the mechanisms of the present invention can deny or permit access to the data encapsulated by the objects.

Object encapsulation protection apparatus

A computer system, program product, and method of collecting interned data utilize an interned indicator for an internable data element that indicates whether such a data element is in fact interned within an intern data structure. By maintaining this information, iteration completely through the intern data structure during collection may be avoided, thereby reducing the overhead and improving the efficiency of the collection process. In addition, a computer system, program product, and method of collecting interned data may also determine during a second stage of a collection cycle whether an interned data element, which was determined to be unreachable during a first stage of the collection cycle, has subsequently been accessed through an intern data structure since the beginning of the first stage of the collection cycle. By making this determination, interned data that has been made reachable as a result of an access through the intern data structure that occurs after the beginning of the first stage of the current collection cycle is prevented from being collected.

Computer system, program product and method of collecting interned data

A computer system, program product, and method of managing weak references with a concurrent mark sweep collector inhibit access, while processing weak references, to only those weak references whose referenced objects have not yet been determined to be strongly-reachable (i.e., reachable other than through a weak reference) during a current collection cycle. As such, access to specific weak references during processing thereof by a concurrent mark sweep collector is selectively inhibited to ensure synchronization for all weak references without necessarily stopping the execution of all program threads that attempt to access such weak references while executing in a computer system, thereby minimizing the processing overhead of managing weak references and improving system performance.

Computer system, program product and method of managing weak references

In an object-oriented or object-based computer system, object methods are routed to users (e.g., client programs) after automatically performing supervisory functions. Examples of suitable supervisory functions include authorization checking and locking. One suitable way to automatically perform the supervisory functions is to provide a call method instruction in the operating system that automatically performs these supervisory functions when a user invokes the object method using the instruction. In this manner, the operating system can assure that the user calling the object method has sufficient authority and lock to access the object method. In addition, the method routing mechanism has the ability to forego authorization checking and locking for objects that are unprotected, and may perform abbreviated authorization checking and locking if the operating system determines from local knowledge that a user is currently authorized to and locked on the called object.

Object-oriented method routing mechanism for automatically performing

A data processing system includes at least one processor and data storage containing an array including N records having value-ordered entries. To find an entry matching a search value, W, a number of records to be searched, is set equal to N, and each of the W records is assigned to either a first set or a second set, where the first set includes X/2 of the W records and X is a smallest power of 2 equal to or greater than W. In response to a determination that the search value precedes the first record within the second set, a binary search of the first set of records is performed to identify a record including an matching entry. If the first entry of the first record within the second set matches the search value, the first record within the second set is identified. However, if the search value follows the first entry of the first record of the second set, the selected record is identified as containing an entry matching the search value only if W is equal to 1, and if W is not equal to 1, W is reset equal to a number of records within the second set and the above steps are repeated until a record containing a matching entry is identified. Following identification of the search value, at least one entry is retrieved from the identified record and contents of the at least one entry are processed within a processor.

Method and system for searching an array for an array value

A method and data processing system for emulating a program are disclosed. According to the present invention, the data processing system runs under a first operating system and emulates the execution of a program under a second operating system within a second data processing system. The data processing system includes a memory which stores at least a portion of the first operating system and an emulator comprising a plurality of routines which each emulate an instruction utilized by the first operating system. The memory further includes a simulated mass storage data area which stores at least a portion of the program and a simulated main memory data area. The data processing system further includes a processor which executes instructions within the program under the first operating system by emulation. According to the present invention, the emulator accesses instructions of the program directly from the simulated mass storage data area to minimize emulation overhead. According to a second aspect of the present invention, the data processing system further includes a cache memory comprising a number of cache lines. The routines are stored within main memory such that when the routines are mapped into the cache, a first instruction within each of the emulation routines is aligned with a different one of the cache lines. According to a third aspect of the present invention, when executing instructions within a routine of a first emulated instruction, the processor prefetches a second emulated instruction prior to completion of the first emulated instruction.

Method and system for handling interrupts during emulation of a program

Method and data processing system for emulating a program

Efficient method router that supports multiple simultaneous object

The present invention utilizes a hardware Window Storage Protection Controller (WSPC) and an Object Encapsulation Enforcement Manager (OEEM) to limit access to object data to only those methods which are encapsulated by the object. All of the objects of the computer system which require protection are stored in protected storage by a base storage protection mechanism so that only the mechanisms of the present invention can deny or permit access to the data encapsulated by the objects.

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Rochester, MN, United States of America

John Clarence Endicott