Abstract: A method and apparatus for persistently storing information objects in a secondary store is provided. Each object to be stored persistently is made a subclass of a persistent object class. The persistent object declares metadata that defines parameters of a table in the secondary store in which instances of the object are stored, and external requirements of the object. When a persistent object inherits attributes from one or more parent object classes, instances of each parent class are represented in separate tables. When a persistent object is read or written by an application program, methods in the persistent object class automatically retrieve or store information for each field of the persistent object by recursively calling a read method or a write method for each class from which the persistent object inherits, and the object's own class. The read method and write methods automatically create and submit commands to the secondary store.

Abstract: A method and apparatus is disclosed for dynamically determining the order of execution of a plurality of computer program components. A characterization mechanism provides an annotation of each executable component. A partial order mechanism depends upon the characterization mechanism, and enables a first executable component to declare which other executable components, times, data sets, or other resources are pre-conditions to execution of the first executable component. At load time, a partial order evaluator resolves the pre-conditions and generates a final order of execution of the components based upon interdependencies and resource requirements represented in the pre-conditions. In a preferred embodiment, the pre-conditions are stored in an acyclic directed graph, and the final order is generated by making a breadth-first traversal of the graph and adding nodes of the graph to the final order in the order in which the nodes are traversed.

Abstract: A method and apparatus are provided for verifying policies that govern a policy-based system. The method and apparatus may be implemented as a policy verifier that acts upon one or more policies. Each policy comprises a condition and a consequent. The policy verifier acquires configuration information about the system under management, thereby acquiring an understanding of the system. The policy verifier determines whether all the policies are feasible for the system, and if not, reports problems or errors that cause the policies to be non-feasible. The policy verifier also verifies that a configuration required by a particular policy consequent can be actually carried out by the managed system. In one embodiment, the policy verifier operates on network management policies, of a policy-based network management system. As a result, the invention improves the accuracy and safety of policies prepared for a network that previously did not use policy-based management.

Abstract: A method and apparatus are provided for recognizing and processing conflicts in policies that govern a policy-based system. The method and apparatus may be implemented as a policy verifier that acts upon one or more policies. Each policy is formally defined and comprises a condition and a consequent, each of which are further formally defined in terms of component elements. A conflict among two or more policies is formally defined to occur when the condition of a first policy and the condition of a second policy may be simultaneously true, and when the consequent of the first policy and the consequent of the second policy may not be carried out simultaneously. When a policy conflict is detected, the conflict is resolved by bringing it to the attention of a user or external system, and receiving information that corrects one of the policies or specifies a precedence relationship among the policies.

Abstract: A method and apparatus are provided for verifying policies that govern a policy-based system. The method and apparatus may be implemented as a policy verifier that acts upon one or more policies. Each policy comprises a condition and a consequent. The policy verifier acquires configuration information about the system under management, thereby acquiring an understanding of the system. The policy verifier determines whether all the policies can be satisfied by the system, and if not, reports problems or errors in the policies that cause the policies to be non-satisfiable. The policy verifier determines whether all the policies are feasible for the system, and if not, reports problems or errors that cause the policies to be non-feasible. The policy verifier also verifies that a configuration required by a particular policy consequent can be actually carried out by the managed system. In one embodiment, the policy verifier operates on network management policies, of a policy-based network management system.

Abstract: A network browsing system includes a host computer coupled to a client computer by a network. A network browser process implemented on the client computer is capable of establishing a connection with the host computer and of generating a request for desired data from the host computer which is to generate desired images on the display of the client computer. A server process implemented on the host computer services the request for desired data received from the client computer by modifying the desired data into modified data such that no additional connection between the client computer and the host computer is required to receive the entirety of the modified data. The browser process of the client computer can generate the desired images from the modified data to the same extent that it could from the originally requested desired data.

Abstract: In a network management system, a method and apparatus for preparing a computer program for execution in relation to a particular network device among a plurality of network devices having a plurality of device types is provided. Each network device is associated with a device type value, and each network device has an associated device mapper. The device mappers are stored in a hierarchical structure that reflects a functional relationship or family relationship of the devices. Functions to be carried out by one or more devices are expressed as a plurality of executable program components. Preferably, each executable program component has one or more classes that define executable functions. Each device mapper associates a device type value with one or more overridden classes in the executable program components and one or more overriding classes. At runtime, device type values are acquired for each device in the managed network.

Abstract: A method and apparatus for parallel processing is provided. A parallel execution object organizes and initiates execution of two or more parallel processing threads that act on members in the context of a transaction. The members comprise one or more sets of data for which parallel processing is needed, for example, sets of network device data. The threads are organized by receiving a set of execution components that have a partial order defined by preconditions and resource requirements. A partial order evaluator resolves the partial order into a final order of execution of the components. The parallel execution object, members, transaction, and partial order can be declared in the context of an application program. Optionally, the threads are organized by selecting execution components that are optimized for use with a particular current phase of execution of the application program.

Abstract: A network browsing system includes a host computer coupled to a client computer by a network. A network browser process implemented on the client computer is capable of establishing a connection with the host computer and of generating a request for desired data from the host computer which is to generate desired images on the display of the client computer. A server process implemented on the host computer services the request for desired data received from the client computer by modifying the desired data into modified data such that no additional connection between the client computer and the host computer is required to receive the entirety of the modified data. The browser process of the client computer can generate the desired images from the modified data to the same extent that it could from the originally requested desired data.

Abstract: A universal addressing system for use in a digital data processing system including a universal memory for storing data including instructions and at least one local system having access to the universal memory. The universal memory is organized into objects, and each item of data is associated with an object. Each object is specified by a unique identifier, and data is addressed by means of a logical address which specifies the UID of the object containing the data and the offset of the data in the object. A processor in the local system responds to instructions by providing memory operation specifiers to the universal memory. Each memory operation specifier specifies a memory operation and a logical address. The offset in the logical address may specify any bit in the object. The memory operation specifier also specifies a length in bits.

Abstract: A digital computer system having a memory system organized into objects for storing data and a processor for processing data in response to instructions. An object identifier and an access control list are associated with each object. The memory system responds to logical addresses for data which specify the object containing the data and the offset of the data in the object and to a current subject for which the processor is referencing the data. The memory system performs a memory operation for the processor only if the access control list for the object specified by the logical address allows the current subject to perform the desired memory operation. The objects include procedure objects and data objects. The procedure objects contain procedures including the instructions and name tables associated with the procedures. The instructions contain operations codes and names representing data. Each name corresponds to a name table entry in the name table associated with the procedure.

Abstract: A digital computer system having a memory system organized into procedure and data objects, each having a unique identifier code and an access control list, for storing items of information and a processor for processing data in response to instructions. The instructions contain operation codes and names representing data. Each name corresponds to a name table entry in a name table which contains information from which the processor determines the location and the format for the data. The name table entry specifies a base address of one of a set thereof which change value only when a call or a return instruction is executed. A name interpretation system fetches a name table entry, calculates the base address and a displacement using the name table entry and the current architectural base address and adds the base address to the displacement to form the address of the data represented by the name.

Abstract: A digital data processing system including a processor and memory and employing object addressing. The digital data processing system further includes a system for organizing the system's memory into objects and a system for operating the memory. The memory organization system associates each item of data stored in the memory with an object and each object with an object identifier. The memory operation system performs memory operations on items of data in response to memory operation specifiers received from the processor. The location of a data item upon which a memory operation is to be performed is specified by a logical address. Each logical address contains an object number which is temporarily associated with one object identifier and an offset specifying a location in the object identified by the object identifier currently associated with the object number.

Abstract: A digital computer system having a memory system organized into objects for storing items of information and a processor for processing data in response to instructions. An object identifier code is associated with each object. The objects include procedure objects and data objects. The procedure objects contain procedures including the instructions and name tables associated with the procedures. The instructions contain operation codes and names representing data. Each name corresponds to a name table entry in the name table associated with the procedure. The name table for a name contains information from which the processor may determine the location and the format for the data (e.g., an operand) represented by the name.

Abstract: A digital computer system having a memory system organized into objects for storing data and a processor for processing data in response to instructions. An object identifier is associated with each object. The memory system responds to logical addresses for data which specify the object containing the data and the offset of the data in the object. The objects include procedure objects and data objects. The procedure objects contain procedures including the instructions. Each instruction contains an operation code which belongs to one of several sets of operation codes. All instructions in a single procedure belong to a single operation code set, and associated with each procedure is an operation code set identifier specifying the operation code set to which the instructions in the procedure belongs.

Abstract: An access control system for use in a digital computer system wherein the memory system is organized into objects, a data item is locatable by specifying an object, instructions are contained in procedures, and the operations performed by the system include a call operation for suspending an execution of a procedure and commencing another execution and a return operation for terminating an execution and resuming a suspended execution. The access control system associates each procedure with a domain, i.e., a set of objects accessible to the procedure. The access control system further includes a secure stack object which is accessible only to the access control system. When a call operation commences execution of a procedure which has a different domain, the access control system responds to the call operation by storing information required to return to the current domain in the secure stack.

Abstract: A digital computer system in which data storage is referred to by a descriptor comprising an object number denoting a variable-length block of storage, an offset indicating how far into that block a desired data item begins, and a length field denoting the length of the desired data item. Separate means exist for manipulating each of the three descriptor portions, thus facilitating repetitive operations on related or contiguous operands. Various levels of microcode control are included. Each level of microcode control has its own stack, facilitating interrupts between levels. Stacks are duplicated in "secure stacks" in memory to protect against loss of state data from the stacks.

Abstract: A digital data processing system has a memory organized into objects containing at least operands and instructions. Each object is identified by a unique and permanent identifier code which identifies the data processing system and the object. The system uses a protection technique to prevent unauthorized access to objects by users who are identified by a subject number which identifies the user, a process of the system for executing a user's procedure, and the type of operation of the system to be performed by the user's procedure. An access control list for each object includes an access control list entry for each subject having access rights to the object and means for confirming that a particular active subject has access rights to a particular object before permitting access to the object. The system also includes stacks for containing information relating to the current state of execution of the system.

Abstract: A digital computer system in which data operands are represented by names. Each procedure includes a name table, and means are provided to employ the name table to resolve the names into storage addresses at run time. The system also has the ability to run any of a plurality of S-Languages (an S-Language being conceptually similar to a machine language but of higher order); each S-Language can be optimally tailored to a high-order user language. Each procedure includes a dialect code which indicates the dialect of S-Language to which the instructions in the current procedure belong, and the system has provision to execute each procedure accordingly.

Abstract: A digital computer system including a memory and a processor. The memory operates in response to memory commands received from the processor. Items of data stored in the memory include instructions to which the processor responds. Each instruction contains an operation code which belongs to one of several sets of operation codes. The meaning of a given operation code is determined by the operation code set to which the instruction belongs. Some of the instructions also contain names representing items of data used in the operation specified by the operation code. The processor includes an operation code decoding system which decodes the operation code as required for the instruction set to which it belongs, a name resolution system for deriving the address of the data item represented by a name from the name using an architectural base address contained in the name resolution system, and a control system which controls the operation of the processor.