Abstract: Improved techniques for representation of objects in a Java programming environment are disclosed. The techniques are highly suitable for representation of Java objects inside virtual machines, especially those that operate with limited resources (e.g., embedded systems). In accordance with one embodiment, a Java object representation is disclosed. As will be appreciated, the Java object representation provides a reference that can be used to directly access the internal class representation associated with the object. The internal class representation provides information regarding the Java object (e.g., object size, object type, static fields, etc.) As a result, information regarding Java objects can quickly be accessed. This means that the processing time conventionally needed to access information regarding Java objects is reduced. Thus, performance of virtual machines, especially in systems with limited computing power and/or memory, can be enhanced.

Abstract: A CPCI system is adapted to reliably detect the presence of all front cards, whether hot swappable or not. The system includes a line that is used to detect the presence of a front card. The line is connected to a connector-pin of a slot. The line is also connected to a pull-up resistor so that when a front card is not inserted in the slot, the line has a high value. When a front card is inserted in the slot, the connector-pin mates with a corresponding connector-pin in the front card. The corresponding connector-pin is connected to a ground layer of the front card so that the line becomes grounded. The voltage level on the line is input to a register that outputs a high or low to a circuit for detecting the presence of a front card. The circuit may be a hot swap controller, a CPU or a status indicator. Accordingly, depending on the output of the register, the circuit reliably determines whether a front card is present in the particular slot.

Abstract: Use of a policy object for verification in a distributed system. A machine downloads a policy object containing a reference to code governing verification of data. The machine uses the reference to obtain the code and locally verify data or other information. As particular rules for the data change, the policy object may be updated to provide a reference to the code for the new rules when it is downloaded.

Abstract: Software techniques are employed to mitigate soft errors. In particular, a compiler (or other executable code generator) may emit otherwise duplicative instructions targeting otherwise duplicative storage locations to facilitate run-time detection and, in some cases, mitigation of soft errors. In general, a compiler emits a program sequence of primary instructions that correspond to source code. However, in addition, for those primary instructions that target storage susceptible to soft errors, the compiler may emit corresponding additional instructions that target additional storage. In some implementations the additional storage is not itself susceptible to soft errors. However, more generally, implementations may tolerate soft errors affecting the additional storage, as long as such soft errors are generally uncorrelated with those affecting the storage targeted by the primary instructions.

Abstract: Improved techniques for storing and retrieving field descriptors in Java computing environments are disclosed. The techniques can be used to implement garbage collection for Java programs in a manner that is more efficient, especially for systems with limited resources (e.g., embedded systems). A reference identifier suitable for use by a Java virtual machine is disclosed. The reference identifier is associated with a Java object and can be stored in the internal class representation associated with the Java object at load time. Moreover, the reference identifier can be used at runtime to quickly determine whether a field of the associated Java object is a reference to another Java object. As a result, the amount of processing conventionally performed at runtime is reduced. This, in turn, can improve the runtime performance of Java virtual machines, especially those operating with limited resources (e.g., embedded systems).

Abstract: Access is provided in an object-oriented computing environment by an instance of a first class to a selected protected resource of an instance of a second class. This involves defining a third class that includes a protected virtual method for accessing the selected protected resource. The first class is defined as a subclass of the third class such that the first class inherits from the third class an access-resource method for the protected resource and a pointer to an instance of the second class as an implementation of the third class. The second class is defined as a subclass of the third class such that the second class inherits from the third class and implements the protected virtual method for accessing the selected protected resource by overloading that method.

Abstract: Improved techniques for representation of Java data types in virtual machines are disclosed. The techniques can be implemented to represent signatures of Java methods as arrays of references. Each of the references in an array can represent a parameter for a Java method. Accordingly, a signature can be represented as an array of references, wherein each reference in the array can reference a Java type indicator or an internal class representation. The Java type indicator represents a Java primitive type (e.g., byte, integer, double, etc.) The internal class representation is typically the representation of a Java class as represented in a virtual machine. As will be appreciated, an array organization allows for more efficient access to information. Thus, unlike conventional techniques, there is no need to start at the beginning of the signature and sequentially read it to find a particular parameter's data type.

Abstract: The present invention provides an instruction fetch unit aligner. In one embodiment, an apparatus for an instruction fetch unit aligner includes selection logic for selecting a non-power of two size instruction from power of two size instruction data, and control logic for controlling the selection logic.

Abstract: A program controlled apparatus includes one or more units for executing a multiple process. A mutex ordering mechanism controls the ordering of mutex ownership to provide deterministic execution of the processes. A mutex processor monitors mutex registers for determining mutex ownership. The mutex registers can be configured as sets of mutex request registers and mutex release registers. The apparatus may include a single processor configured to execute multiple processes concurrently, or multiple processing units, each configured to execute one or more processes. A monitor unit which can monitor equivalent operation of the processing sets can also include the mutex ordering mechanism.

Abstract: Information regarding the operating conditions of a computer system is stored in a storage which is dedicated to a failure management system. The storage is updated with the current operating conditions either periodically or upon the occurrence of predetermined events. When a first failure identification mechanism identifies a failure in the computer system, a capture mechanism interrupts the updating of the storage leaving information regarding operating conditions which contributed to the failure in the storage. This latter information can then be read out to aid in diagnosis of the failure. Since the operating condition information is stored in a dedicated storage, the information is not modified by events that take place after the failure is identified. In accordance with one embodiment, the computer system ordinarily holds state and other operating information in a set of storage devices, such as, for example, state registers.

Abstract: To cool heat-emitting electronic components, a compact, non-moving-parts compressor, an evaporator in juxtaposition to the electronic components and a condenser are mounted as a unit, preferably within a vacuum can. A heat exchanger is mounted external to the can but in proximity to the condenser. The foregoing comprise a unit which may be detachably connected to a host pump and heat exchanger. The unit may be removed from the system of which it is a part for upgrade and maintenance. All its components are thermally isolated from the ambient atmosphere to prevent water vapor condensation corrosion.

Abstract: An isolation mounting system attaches a computer component, such as a disk drive, to the structure of a computer system. In an embodiment, the isolation mounting system comprises a post bracket attached to the computer component, a plurality of isolators attached to posts extending from the post bracket, and a socket bracket attached to the isolators and to the structure of the computer system. An opening in the isolators fits over, onto, or around the posts of the post bracket. Outer surfaces of the isolators fit within receptacles of the socket bracket.

Abstract: A system for minimizing the effect of clock skew in a bit line write driver includes a first control circuit coupled to the bit line write driver; and a second control circuit coupled to the bit line write driver. The bit line write driver outputs a first output signal and a second output signal. A method of minimizing the effect of clock skew in a bit line write driver includes outputting a first signal and a second signal from the bit line write driver; controlling the outputting of the second signal from the bit line write driver based on a feedback of the first signal; and controlling the outputting of the first signal from the bit line write driver based on feedback of the second signal.

Abstract: In accordance with methods and systems consistent with the present invention, a lease manager is provided for managing leases between clients and other network services. To use the lease manager, a client enters into a management lease with the lease manager, specifying an amount of time during which the lease manager can manage preexisting leases between the client and network services on behalf of the client. This management includes renewing the preexisting leases with the other network services. Further, the lease manager notifies the client when a lease between the lease manager and the client is near expiration. The lease manager also notifies the client of failed attempts to renew the preexisting leases, as well as the management lease, either with a network service or with the lease manager.

Abstract: A system for minimizing the effect of clock skew in a precharge circuit includes a switch coupled between an input to the precharge circuit and a global bitline; and a control circuit coupled to a precharge component and the switch. The control circuit determines whether the switch and the precharge component are activated and the control circuit receives feedback from the switch. A method of minimizing the effect of clock skew in a precharge circuit includes controlling whether an input signal outputting a first signal and a second signal from the precharge circuit; controlling the outputting of the second signal from the precharge circuit based on a clock signal, a select signal, and a dynamic signal.

Abstract: For an integrated circuit having multiple metal layers, a computer-aided design (CAD) method for designing grounded fill in the integrated circuit includes: (a) finding the eligible fill areas for each metal layer; (b) storing the eligible fill area data for each metal layer in an overflow memory; (c) finding ground contact areas for each metal layer; (d) storing the ground contact area data for each metal layer in an overflow memory; (e) temporarily storing the eligible fill area data for a selected metal layer and the ground contact area data for the metal layers adjacent to the selected metal layer in active memory; (f) fitting a fill pattern to an eligible fill area in the selected metal layer, where the fill pattern is composed of at least one element; (g) checking the adjacent metal layers for a ground contact where the element of the fill pattern may be grounded; (h) locating a conductive via between the element of the fill pattern and a ground contact in an adjacent layer; and (i) repeating steps (e)

Abstract: A method and apparatus is provided for restoring a free physical register list to its previous state without having to physically restore any data. The method and semiconductor device utilizes sets of pointers to manage physical register pointers in the physical register list. The physical register list is able to independently track physical registers for multiple threads of a multithreading microprocessor.

Abstract: A data transfer control system for a computer system having a packet-switched data bus, for controlling the transfer of data words from a device having one bus width to a device having a different bus width. The first bus may be the master bus, and the second bus is a bus of a functional unit, such as a memory or other device, connected to the computer system and coupled to the master bus. When the second bus is smaller than the first bus, the data transfer control system accommodates this by transferring only partial words per clock cycle to the second bus, effectively delaying the transference of data to a rate that the second bus can handle. The transfer rate factor is substantially equal to the ratio of the second bus width to the first bus width.

Abstract: Techniques for implementing virtual machine instructions suitable for execution in virtual machines are disclosed. The inventive virtual machine instructions can effectively represent the complete set of operations performed by the conventional Java Bytecode instruction set. Moreover, the operations performed by conventional instructions can be performed by relatively fewer inventive virtual machine instructions. Thus, a more elegant, yet robust, virtual machine instruction set can be implemented. This, in turn, allows implementation of relatively simpler interpreters as well as allowing alternative uses of the limited 256 (28) Bytecode representation (e.g., a macro representing a set of commands). As a result, the performance of virtual machines, especially, those operating in systems with limited resources, can be improved by using the inventive virtual machine instructions.

Abstract: A method and apparatus for securely communicating ephemeral information from a first node to a second node. In a first embodiment, the first node encodes and transmits an ephemeral message encrypted at least in part with an ephemeral key, from the first node to the second node. Only the second node has available to it the information that is needed to achieve decryption by an ephemeral key server of a decryption key that is needed to decrypt certain encrypted payload information contained within the message communicated from the first node to the second node. In a second embodiment the first node transmits to the second node an ephemeral message that is encrypted at least in part with an ephemeral key. The ephemeral message includes enough information to permit the second node to communicate at least a portion of the message to an ephemeral key server and for the ephemeral key server to verify that the second node is an authorized decryption agent for the message.