Abstract: Systems, especially operating systems, are becoming more complex to the point where maintaining them by humans is becoming nearly impossible. Many corporations have recognized this trend and have begun investing in autonomic technology. Autonomic technology allows a piece of software to monitor, diagnose, and repair itself. This can be used for improved performance, reliability, maintainability, security, etc. Disclosed herein is a mechanism to allow operating systems to hot swap a piece of operating system code, while continuing to offer to the user the service which that code is providing. This can be used, for examples, to increase the performance of an application or to fix a detected security hole live without bringing the machine down. Some autonomic ability will be mandatory in next generation operating system for without it they will collapse under their own complexity. The invention offers a key component of being able to achieve autonomic computing.

Abstract: A method and apparatus for performing efficient interprocess communication (IPC) in a computer system. With this invention, a memory region called the IPC transfer region is shared among all processes of the system to enable more efficient IPC. The unique physical address of the region is mapped into a virtual address from each of the address spaces of the processes of the system. When one of the processes needs to transfer data to another of the processes, the first process stores arguments describing the data in the region using the virtual address in its address space that maps into the unique physical address. When the other or second process needs to receive the data, the second process reads the data from the second region using the virtual address in its memory space that maps into the unique physical address. With this invention, in most cases, control of the IPC transfer region occurs automatically without any kernel intervention.

Abstract: In a computer system, a method and apparatus for scheduling activities' access to a resource with minimal involvement of the kernel of the operating system. More specifically, a “next bid” is maintained, and this parameter identifies the highest bid for the resource by any activity not currently accessing the resource. The accessing activity then compares its bid, which can be time varying, with the “next bid” to determine whether it should release the resource to another activity. The “next bid” can be accessed without any system calls to the operating system. This allows the activity to determine whether to relinquish control to the system without the necessity of communication between the two. Likewise, the operating system can access the bid of the accessing activity without explicit communication. This allows the system to determine whether to preempt the accessing activity without the necessity of communication between the two.

Abstract: There is provided a method for representing unvalues in an unvalue-unaware memory of a computer processing system. The method includes the step of selecting arbitrary bit combinations to represent the unvalues, upon startup of the system. Upon performing a read operation from the memory, a read value is interpreted as an unvalue, when the read value matches at least one of the bit combinations. Upon performing a write operation to the memory, a value-unvalue-collision exception is raised, when a valid value is written to the memory and the valid value matches at least one of the bit combinations.

Abstract: A method and apparatus for performing efficient interprocess communication (IPC) in a computer system. With this invention, a memory region called the IPC transfer region is shared among all processes of the system to enable more efficient IPC. The unique physical address of the region is mapped into a virtual address from each of the address spaces of the processes of the system. When one of the processes needs to transfer data to another of the processes, the first process stores arguments describing the data in the region using the virtual address in its address space that maps into the unique physical address. When the other or second process needs to receive the data, the second process reads the data from the second region using the virtual address in its memory space that maps into the unique physical address. With this invention, in most cases, control of the IPC transfer region occurs automatically without any kernel intervention.

Abstract: A conventional bi-endian computer system is enhanced to include mixed-endian mechanisms that allows the computer system to dynamically change its endian mode. The mixed-endian computer system can change endian mode on a task by task basis if necessary. The mixed-endian mechanisms automatically format the data in the form expected by the running task, regardless of whether the task expects the data to be in big endian format or in little endian format. The mixed-endian mechanisms also format big and little endian instructions such that they can execute on the same computer system. The mixed-endian mechanisms also include two memory management mechanisms, a single aliased memory management mechanism and a double aliased memory management mechanism. Each memory management mechanism provides cross-endian data sharing.

Abstract: A first group of memory locations stores information. The first group is arranged into multiple congruence classes of memory locations. The congruence classes include a first congruence class having more than one memory location. A second group of memory locations stores information from the first group of memory locations. Directory locations store information relating the first and second groups of memory locations. The directory locations include a first directory location able to store information relating a particular one of the second group of memory locations to any memory location of more than one of the congruence classes including the first congruence class.