Abstract: In an embodiment of the present invention, a first communication packet is assigned to a first communication data structure that is unique to a first connection comprising the first communication packet. A first event list is selected from a database based on a classification of the first communication packet. The first event list identifies a first plurality of communication modules (e.g., socket layer, TCP layer, IP layer, IP security layer, firewall layer, etc.) and an ordering thereof, specific for the needs of the first connection. The first communication packet is processed through the first plurality of communication modules based upon the ordering specified in the first event list. A reference contained in the data structure marks the current packet position though the plurality of communication modules.

Abstract: A method for locating a root block in file system metadata, includes traversing the file system metadata to locate a leaf block, wherein the leaf block comprises a plurality of root blocks and at least one of the plurality of root blocks is unallocated, allocating the at least of one the plurality of unallocated root blocks to obtain an allocated root block, wherein the leaf block is associated with a fill count and the fill count is less than a maximum fill count of the leaf block.

Abstract: A cluster or group of cooperating systems may implement failure chain detection and recovery. The group may include multiple nodes and each node may include a group management services (GMS) module that in turn may include a group communications mechanism to detect cluster membership events. Each GMS module may maintain an identically ordered view of the current group membership. When a member of the group fails, the member that joined the group immediately after the failed member, according to respective join times, may be selected to perform recovery operations for the failed member. If a group member fails while performing recovery operations for another failed member, the next member in the group (according to respective join times) may be selected to perform recovery for that node and may also perform recovery operations for the original failed node as well.

Abstract: One embodiment of the present invention provides a system that facilitates manipulating a 2D window within a three-dimensional (3D) display model. During operation, the system receives an input from a 2D pointing device, wherein the input specifies a 2D offset within a 2D display, and wherein the 2D display provides a view into the 3D display model. Next, the system uses the 2D offset to move a cursor to a position in the 2D display, and then determines if the cursor overlaps a window within the 3D display model. If so, the system determines a 2D position of the cursor with respect to a 2D coordinate system for the window, and communicates this 2D position to an application associated with the window. This enables a user of the 2D pointing device to interact with the application.

Abstract: We propose a class of mechanisms to support a new style of synchronization that offers simple and efficient solutions to several existing problems for which existing solutions are complicated, expensive, and/or otherwise inadequate. In general, the proposed mechanisms allow a program to read from a first memory location (called the “flagged” location), and to then continue execution, storing values to zero or more other memory locations such that these stores take effect (i.e., become visible in the memory system) only while the flagged memory location does not change. In some embodiments, the mechanisms further allow the program to determine when the first memory location has changed. We call the proposed mechanisms conditional multi-store synchronization mechanisms.

Abstract: In one embodiment, a node for a multi-node computer system comprises a coherence directory and a coherence controller. The coherence directory comprises a plurality of entries, wherein each entry corresponds to a respective coherence unit and stores a state identifying which nodes in the computer system are storing a copy of the coherence unit and further identifying a coherence state of the coherence unit according to a coherence protocol implemented in the computer system. Coupled to the directory and coupled to receive a first request for a requested coherence unit having a first entry in the coherence directory, the coherence controller is coupled to receive a second request for the requested coherence unit. The coherence controller is configured to selectively initiate coherence activity for the second request, if coherence activity for the first request is not yet complete, dependent on a type of the second request.

Abstract: Reference updating in a sliding compaction garbage collector may involve maintaining, for each logical region of the heap to be compacted, values that represent the range of addresses referenced by individual regions of the heap. For example, a highest-referenced address (HRA) represents the maximum address referenced by any object references in the respective region. Similarly, a lowest-reference address (LRA) represents the minimum address referenced by a region. When updating references during compaction, if the HRA and/or LRA for a particular region indicate that all references within the region point to addresses within a region of memory that will not be relocated during compaction, such as a dense prefix, the references with the particular region need not be updated. Maintaining HRAs and/or LRAs for region of heap memory may simplify determining whether or not references within individual regions require updating.

Abstract: A mask is first generated in a general-purpose integer register. The mask is generated by executing a single instruction multiple data (SIMD) instruction on a plurality of operands stored in a plurality of registers and by writing the result to the general-purpose integer register. Next, a conditional-move mask is generated in a register using the mask, and then the conditional-move mask is used in selecting operands from the plurality of operands to generate a result in another register.

Abstract: In one embodiment, a system comprises a source configured to provide data and a source error correction code (ECC) generated according to a source ECC scheme; a circuit comprising an ECC transform unit configured to generate a target ECC from the data, detect an error in the data responsive to the source ECC, and correct the error in the data, wherein the target ECC is generated according to a target ECC scheme different from the source ECC scheme, and wherein the ECC transform unit is configured to continuously protect the data with at least one of the source ECC and the target ECC; and a target coupled to receive the data and the target ECC from the circuit.

Abstract: A system to execute an application comprises a cluster of a plurality of application server nodes. A particular one or more of the application server nodes has residing thereon at least one container that contains business logic for the application. The particular one or more of the application server nodes is configured to maintain self-timing information for use to schedule execution of the business logic contained by the at least one container residing on the particular one or more application server nodes. Also, at least one of the other application server nodes is configured to maintain backup timing information for the particular one or more of the application server nodes, from which the self-timing information maintained by the particular one or more of the application server nodes can be derived.

Abstract: One embodiment of the present invention provides a system for troubleshooting a computer system. During operation, the system receives an identifier for a suspect computer system, which is suspected of operating abnormally. The system also receives an identifier for a normal computer system, which is operating normally. Next, the system automatically sends a command to be executed to both the suspect computer system and to the normal computer system. The system subsequently receives a response to the command from both the suspect computer system and the normal computer system and compares the responses to determine differences in behavior between the suspect computer system and the normal computer system.

Abstract: A system that reduces the size of a design data set. During this design data set reduction operation, the system computes a decision boundary which separates a first group of data patterns in a training data set from a second group of data patterns in the training data set. For each data pattern in the training data set, the system determines if removing the data pattern from the training data set substantially affects the resulting decision boundary. If so, the system marks the data pattern as a key pattern. The system then removes all data patterns that are not marked as key patterns to produce a reduced training data set which represents the decision boundary.

Abstract: An apparatus and method to support pipelining of variable-latency instructions in a multithreaded processor. In one embodiment, a processor may include instruction fetch logic configured to issue a first and a second instruction from different ones of a plurality of threads during successive cycles. The processor may also include first and second execution units respectively configured to execute shorter-latency and longer-latency instructions and to respectively write shorter-latency or longer-latency instruction results to a result write port during a first or second writeback stage. The first writeback stage may occur a fewer number of cycles after instruction issue than the second writeback stage. The instruction fetch logic may be further configured to guarantee result write port access by the second execution unit during the second writeback stage by preventing the shorter-latency instruction from issuing during a cycle for which the first writeback stage collides with the second writeback stage.

Abstract: A system for mapping memory of a computer system includes a sorter, a partitioner, and a mapper. The sorter sorts a physical memory space to obtain a sorted virtual memory space, where the physical memory space includes a plurality of memory patterns, wherein each of the plurality of memory patterns is associated with a physical device and includes at least one memory block, wherein the at least one memory block is contiguous and addressable, and the plurality of memory patterns are arranged based on a predefined number of occurrences of each memory pattern, size of contiguous memory address ranges in each of the plurality of memory patterns, size of contiguous memory address ranges in each of the plurality of memory patterns, and arrangement of contiguous address ranges in each of the plurality of memory patterns.

Abstract: A generic conversion framework that allows developers to develop custom plug-in conversion algorithms and/or merge algorithms (referred to as pluggable modules). In one embodiment, document merging may be split into two processes including a document differencing process and a document merging process. The converter, differencing and merger processes may be implemented as separate pluggable modules, allowing multiple, independent passes of implementations of the differencing process and the merge process. The framework may accept document converter plug-in modules, merger plug-in modules and/or differencing plug-in modules to be added, updated or replaced as needed. In one embodiment, the modules may be plugged into the framework dynamically at runtime. In one embodiment, a plug-in module of one type may be used with two or more different modules of another type.

Abstract: Web services interface policy constraints may be specified in a policy constraints language and policy processing, such as generating an intersection policy of two policies may be automated by a policy-processing engine. A policy constraint may be a specification of a value, range of values, or set of values that a particular requirement or offering is allowed to have. Hierarchies of requirements and/or offerings may also be expressed and matched such that a more specific case of a requirement or offering may be matched against a more general case of the same requirement or offering. Also, preferences among vocabulary items, vocabulary item values, policy constraints, and other elements of a policy may be specified and automatically determined by a policy-processing engine. Automated matching of consumer requirements against provider offerings may allow a policy-processing engine to process policies with specifications of requirements or offerings from any domain-specific schema.

Abstract: In an apparatus and method for providing device sharing, a first plurality of upstream ports are each connectable to a respective host and at least one downstream port is connectable to a device. A virtual port is defined that is associated a routing table to effect device virtualization by redirection of information packets received by the virtual port.

Abstract: A method is provided for obtaining data to be used in evaluating performance of a computer processor. More specifically, the method provides for efficiently obtaining traces from an application program for use in a simulation of a computer processor. The method uses both an original code defining the application program and an instrumented version of the original code (“instrumented code”). The method includes apportioning a total time of execution of the application program between the original code and the instrumented code. Transition of execution between the original and instrumented codes is conducted through either modification of function calls or through consultation with a mapping of instruction address correspondences between the original and instrumented codes.

Abstract: A technique for reducing off-chip bandwidth requirements for a processor reads old data from a location in an on-chip store of a processor in preparation of writing new data to the location in the on-chip store. The technique determines whether new data bytes of the new data and associated old data bytes of the old data are different. The new data bytes are then written to the on-chip store. When updating an off-chip store, only the new data bytes that are different are written to the off-chip store. In this manner, off-chip bandwidth requirements for a processor may be reduced.

Abstract: A method for executing input/output (I/O) operations based on priority involves receiving a first I/O request for a unit of data, receiving a second I/O request for the same unit of data, determining a priority of the first I/O request and a priority of the second I/O request, and executing the first I/O request based on priority, where the first I/O request is executed based on the higher of the priority of the first I/O request and the priority of the second I/O request.