Abstract: A graphical user interface permits navigating through a plurality of stacked window layers or image planes. In one form, moving through one image plane to an image plane below simulates pressing on an elastic membrane until it bursts. In another form, worm holes are used to access selected layers at different depths. In another embodiment, a property analogous to thickness, is associated with an image plane and the amount of time or force required to pass through the image plane is controlled as a function of thickness. In yet another form, a force feedback input/output device having three degrees of freedom is used to give a user the feel of physically penetrating through plural stacked layers.

Abstract: One embodiment of the present invention provides a system that facilitates garbage collection and supports space and time dimensional execution of a computer program. The system executes program instructions with a head thread and speculatively executes program instructions in advance of the head thread with a speculative thread. During execution of the speculative thread, the system creates space-time dimensioned versions of objects from a system heap that are modified by the speculative thread. These space-time dimensioned versions of objects are created in a speculative heap that is separate from the system heap. The system keeps a record of objects for which space-time dimensioned versions have been created during updates to value fields and during updates to pointer fields by the speculative thread. This record is used during a garbage collection operation to identify live objects so that the garbage collection operation can move the live objects from the speculative heap to the system heap.

Abstract: A program interpreter for computer programs written in a bytecode language, which uses a restricted set of data type specific bytecodes. The interpreter, prior to executing any bytecode program, executes a bytecode program verifier procedure that verifies the integrity of a specified program by identifying any bytecode instruction that would process data of the wrong type for such a bytecode and any bytecode instruction sequences in the specified program that would cause underflow or overflow of the operand stack. If the program verifier finds any instructions that violate predefined stack usage and data type usage restrictions, execution of the program by the interpreter is prevented. After pre-processing of the program by the verifier, if no program faults were found, the interpreter executes the program without performing operand stack overflow and underflow checks and without performing data type checks on operands stored in operand stack. As a result, program execution speed is greatly improved.

Abstract: A method and apparatus for providing thread-safe disposal of objects in a multi-threaded computer environment. When a thread from a process sends a call to delete an object, that thread typically waits for other threads interacting with that same object to clear. During this waiting period, it is common to have other threads invoking the same object, thus increasing rather than decreasing the number of active threads for that object. Also, problems arise when more than one thread attempts to delete the object. However, the present invention associates a state machine with each object. When an invocation of an object is made, the state machine is queried to detect the state. Invocations made on the object after the occurrence of a delete call interpret the object as having been deleted, and are not added to the active invocations for that object. Further, subsequent delete calls also interpret the object as having been deleted, and return a failure indication.

Abstract: A method for providing for electrical testing of an integrated semiconductor substrate having at least two signal processing layers. The substrate may be provided with a protective layer of plastic, silicon, silicon oxide, silicon nitride or the like. A selected region of one substrate layer to be tested electrically is exposed by etching or otherwise forming a controllably small aperture any overlying substrate layer(s) away to expose at least one selected circuit trace in the selected region and applying a selected electrical signal to the trace. Optionally, a second aperture, spaced apart from the first aperture, can be formed to expose a second selected circuit trace so that propagation of a signal in one or more substrate circuits can be tested. The aperture cross-sectional shapes may be linear or curvilinear polygons or other suitable shapes.

Abstract: Improved methods for the controlled generation of ammonia from an ammoniated metal salt at substantially ambient temperature by applying microwave energy to the salt. The ammoniated salts have the formula MAn.X(NH3), wherein M is at least one metal selected from the group consisting of alkali metals, alkaline earth metals, scandium, ytterbium, the lanthanides, titanium, zirconium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum, tungsten, manganese, technetium, rhenium, iron, ruthenium, osmium, cobalt, rhodium, iridium, nickel, palladium, platinum, copper, silver, gold, zinc, cadmium, mercury, tin, and aluminum; A is at least one ion selected from the group consisting Cl−, Br−, F−, I−, ClO3−, ClO4−, BF4−, AlCl4−, PF6−, SbCl6−, and SbF6−; and SbF6− n is from 1 to 6; and X is from 1 to 8.

Abstract: The invention noninvasively provides information relating to memory space allocation. Memory space allocation information is maintained in a location that is known or identifiable outside of the process for which the memory space has been allocated. A memory space allocator maintains the information in a descriptor block. The descriptor block is updated with every allocation or deallocation of memory space. In the preferred embodiment of the invention, the descriptor block exists on a page of memory having a size equal to the native page size of the machine on which it is operating. The memory allocator allocates memory space in units referred to as buckets that exist within a memory block. The descriptor block contains an identifier that identifies the memory space allocation information stored in that descriptor block as being controlled by a particular memory space allocator. The descriptor block also contains information that indicates how many pages are used and how many pages are free.

Abstract: A multiprocessor computer system which provides fault tolerance includes a number of processing sets. At least one of the processing sets is operable asynchronously of a second processing set. A monitor is connected to receive I/O operations output from the processing sets for identifying faulty operation of those units. The monitor is also operable to synchronize operation of the processing sets by signalling the processing sets on receipt of outputs from those units indicative of a plurality of them being at an equivalent stage of processing. The common monitor can be operable to determine not only faulty operation of the processing sets, but also to synchronize those units by monitoring the I/O operations output from the units. The monitor provides for buffering of I/O operations output from the processing sets and for selective forwarding of those I/O operations to an external I/O bus. A processing set may be formed from a single processor, or may be formed from multiple symmetric processors.

Abstract: Calls to a conventional device driver interface of a first operating are converted to operate with a device driver interface of a second operating system. A convention interface is created to appear identical to the conventional device driver interface of the first operating system, but the conversion interface operate in the second operating system. The conversion interface permits a program utilizing the conventional device driver interface of the first operating system to operate in the second operating system without modification to the source code.

Abstract: A method and apparatus for operating a local server computer of a client-server network includes a technique to receive a request from a client computer of the client-server network. A determination is made whether the request requires dynamically generated information from a servlet object of the client-server network. If so, a specified servlet object corresponding to the request may be uploaded from a remote server computer of the client-server network. The specified servlet object is then executed to obtain dynamically generated information corresponding to the request.

Abstract: A structured software exception-handling mechanism and method provides an improved paradigm for managing program flow control after error detection without requiring compiler modifications. Selected code is wrapped in one or more exception handling constructs which can be nested. Exceptions are raised and handled in accordance with specified handlers or by a default handler outside the scope of specified exception code wrappers.

Abstract: A method for storing mip map series in a multi-bank texture memory is disclosed. Each mip map has a different size and represents a different resolution version of a texture map image that is to be mapped onto a three dimensional object comprising one or more polygons. To prevent page faults when accessing corresponding texels in consecutive mip maps, each mip map is divided in two halves. The halves are stored in different banks of the multi-bank texture memory. The banks used are alternated so that corresponding texels in consecutive mip maps are stored in different memory banks. Mip maps may be categorized as large or small, with all small mip maps after the first being stored in their entirety in one memory bank. Small mip maps are those that are equal to or smaller than the page size of the multi-bank texture memory. A computer system, graphics subsystem, and software program capable to efficiently store mip map series in a multi-bank texture memories are also disclosed.

Abstract: An architecture for a highly integrated network element building block is provided. According to one aspect of the present invention, a network device building block includes a network interface with multiple ports for transmitting and receiving packets over a network. The network device building block also includes a packet buffer storage which is coupled to the network interface. The packet buffer storage acts as an elasticity buffer for adapting between incoming and outgoing bandwidth requirements. A shared memory manager may also be provided dynamically allocate and deallocate buffers in the packet buffer storage on behalf of the network interface and other clients of the packet buffer storage. The network device building block further includes a switch fabric which is coupled to the network interface. The switch fabric provides forwarding decisions for received packets. A given forwarding decision includes a list of ports upon which a particular received packet is to be forwarded.

Abstract: A method, apparatus, and product for leasing a delegation certificate in a distributed processing system is provided. Consistent with this method, apparatus, and product, a delegatee requests from a delegator access to a resource for a period of time that the delegator has authority to access. Responsive to this request, the delegator determines an appropriate lease period during which time the delegatee has authority to access to the resource.

Abstract: Software, method, and systems for representing devices on a computer network are described. In one embodiment the invention comprises a method which identifies devices on a computer network; creates topology objects configured to represent the devices; associates the topology objects with the identified devices; stores the associated topology objects in a database managed by a topology service. The embodiment further is capable of receiving an alarm notification regarding a device having an associated topology object stored in the database, extracting the topology object, and acting on said topology object update an alarm count in the topology object; propagate the alarm notice to other topology nodes associated with the topology object; store information related to the alarm and the database; and notifying other services on the computer network. Other embodiments update the relationships between the devices and associated topology objects stored in the database.

Abstract: A system for using a lease to detect a failure and to perform failure recovery is provided. In using this system, a client requests a lease from a server to utilize a resource managed by the server for a period of time. Responsive to the request, the server grants the lease, and the client continually requests renewal of the lease. If the client fails to renew the lease, the server detects that an error has occurred to the client. Similarly, if the server fails to respond to a renew request, the client detects that an error has occurred to the server. As part of the lease establishment, the client and server exchange failure-recovery routines that each invokes if the other experiences a failure.

Abstract: A method, in a computer network having a first plurality of nodes coupled to a common network infrastructure and a distributed shared memory distributed among the first plurality of nodes, for servicing a memory access request by a first node of the first plurality of nodes. The memory access request pertains to a memory block of a memory module that has a home node different from the first node in the computer network. The home node has a partial directory cache that has fewer directory cache entries than a total number of memory blocks in the memory module. The method includes the step of ascertaining whether the memory block is currently cached in the partial directory cache. If the memory block is currently cached in the partial directory cache, the first memory access request is serviced using a directory protocol. If the memory block is not currently cached in the partial directory cache, the first memory access request is serviced using a directory-less protocol.

Abstract: An improved object-database mapping tool is provided that stores a series of stored procedures associated with a database and an object-oriented application. The tool accesses stored procedures associated with classes corresponding to an object-oriented application. The tool determines a sequence of the stored procedures based on relationships between the classes. The tool loads the stored procedures based upon the sequence. In another aspect of the present invention, the tool uses several steps to sequence the stored procedures. The tool categorizes the stored procedures based on the classes the stored procedures correspond to in the object-oriented application. The tool loads the stored procedures corresponding to classes having relationships to other classes. The tool loads the stored procedures corresponding to classes categorized as superclasses. The tool also loads the stored procedures corresponding to classes categorized as subclasses.

Abstract: A process receives an object-based query and creates a logical tree that contains nodes representing operations that are required for the query to be completed. Operations that can be performed by an RDBMS are transmitted to the RDBMS as an SQL query. The RDBMS executes the SQL query and returns data to the process. The process places the data into appropriate fields of one or more objects, and stores the resulting objects in a memory, such as an object cache. The process executes the remaining node operations (that could not be performed by the RDBMS) in conjunction with the objects stored in the object cache, and forwards the results to a user program.

Abstract: A heat sink assembly includes a heat sink, a circuit board and an integrated circuit package. The package is located between the heat sink and the circuit board and attached to a die attach area of the circuit board. A heat sink retainer attached to the heat sink has a base section located adjacent to the circuit board directly opposite the die attach area. The retainer presses the heat sink down uniformly on the package. Further, the downward force applied to the heat sink is countered by an equal upward force applied by the base section of the retainer on the circuit board. Since the base section is located directly opposite the die attach area, the upward force is transferred from the base section directly back to the heat sink without imparting any bending force on the circuit board.