Abstract: A method schedules execution contexts in a computer system based on memory interactions. The computer system includes a processor and a hierarchical memory arranged in a plurality of levels. Memory transactions are randomly sampled for a plurality of contexts. The contexts can be threads, processes, or hardware contexts. Resource interactions of the plurality of contexts is estimated, and particular contexts are chosen to be scheduled based on the estimated resource interactions.

Abstract: A cryptographic system and method for encrypting and decrypting data using public key cryptography. The encryption and decryption may be divided into tasks that may operate in parallel. A secure method of initializing the cryptographic system to allow for secure operations and protect against tampering with application software. The application program is retrieved from an encrypted file in external memory and authenticated before being executed.

Abstract: The invention provides a method for acquiring a lock in a network of processors with globally ordered remote-writes. A process requesting a lock changes an associated ticket number from zero to one. Next, the process determines if every other process attempting to acquire the lock has a ticket number of zero. If true, the request for the lock is immediately granted. Otherwise, if false, the process changes its ticket number to a value greater than that of every other process, and the process waits until its ticket number is the lowest non-zero ticket number, in which case the lock is granted with mutual exclusion.

Abstract: A multi-user bus is divided into a number of bus portions, one for each user. Each bus portion is coupled, at one end, to one of the multiple users and through an impedance matching network to the other bus portions in a star configuration. The disclosed embodiment teaches various resistive impedance matching networks.

Abstract: A method and apparatus for sorting and classifying communications frames received over a network prior to delivery, using a collection of filters arranged as a decision-making tree with destinations for the frames as the leaves of the tree.

Abstract: A monitor function is implemented to monitor and control service processes and other system entities that perform tasks on a distributed network. The monitor function tracks the demise and instantiation of processes and entities that either export or import instrumentation. Any service process or other system entity (driver, interrupt handler, system library procedure) can export instruments (indicators, controls, testpoints). Instrument updates are propagated automatically if they are significant. The importing process conveys the information to a management system so that a human operator, or automated system, can observe and control the operation of the network service. One aspect of the invention uses a backup exporter to take over the processing of an exporter that has become nonfunctional. Another aspect of the invention determines when a CPU has gone down and acts accordingly to identify service processes that were associated with an exporter in the down CPU.

Abstract: The present invention discloses an apparatus and method for maintaining the coherence of data within a shared memory network including a plurality of nodes. The system utilizes processors monitoring the occurrence of particular processing events within a local memory storage area. Upon the detection of events indicating the change of status of a particular group of data, a comparison is made between a modified copy of the group of data and a clean copy of the group of data to detect any modifications made to the group of data. These modifications are entered into the clean copy of the group of data and processing continues.

Abstract: An encoded loss resilient message, includes a first number of first data items, a second number of second data items, and a third number of third data items. Respective portions of the first data items correspond to different numbers of associated second data items in a first distribution. Respective portions of the second data items correspond to different numbers of associated first data items in a second distribution. Respective portions of the second data items correspond to different numbers of associated third data items in a third distribution which is proportional to the first distribution with the different numbers of associated third data items equaling the different numbers of associated second data items multiplied by the first number divided by the second number.

Abstract: A method of reconstructing an image from a dithered image. A predefined set of filters having different regions of support is established. Each filter is defined by a number of filter coefficients and an impulse response function which defines the filter response for a region of support outside of which the impulse response is zero. Filters are organized according to indexes and this organization represents the order in which the filters are considered during a filter selection process. The filter selection process selects a filter constrained by the rule that the filter selected must only perform low-pass filtering on a region of support that does not contain edges of an image. Due to the organization of the filter set, the filter selection process first selects the largest filter from the filter set that fits within the region about the current processed pixel. If there is an edge of an image within the support region of the first selected filter, the next smaller filter is selected.

Abstract: Entries are cached in a function cache by statically assigning a primary key to each cache entry, and first grouping entries having identical primary keys, and dynamically assigning a secondary key to each cache entry, and then second grouping entries in each primary key group into sub-groups according to their secondary keys. The function cache is first accessed with a particular primary key to get the primary key group. Second, the primary key group is accessed with a particular secondary key to get a sub-group, and third, the sub-group is accessed with the same particular secondary key to get a matching cache entry.