A method and system for leasing storage locations in a distributed processing system is provided. Consistent with this method and system, a client requests access to storage locations for a period of time (lease period) from a server, such as the file system manager. Responsive to this request, the server invokes a lease period algorithm, which considers various factors to determine a lease period during which time the client may access the storage locations. After a lease is granted, the server sends an object to the client that advises the client of the lease period and that provides the client with behavior to modify the lease, like canceling the lease or renewing the lease. The server supports concurrent leases, exact leases, and leases for various types of access. After all leases to a storage location expire, the server reclaims the storage location.

Method and system for leasing storage

An improved lookup service is provided that allows for the dynamic addition and deletion of services. This lookup service allows for the addition and deletion of services automatically, without user intervention. As a result, clients of the lookup service may continue using the lookup service and its associated services while the updates occur. Additionally, the lookup service provides a notification mechanism that can be used by clients to receive a notification when the lookup service is updated. By receiving such a notification, clients can avoid attempting to access a service that is no longer available and can make use of new services as soon as they are added to the lookup service.

Dynamic lookup service in a distributed system

In accordance with the present invention a process is provided for allocating and deallocating resources in a distributed processing system having a requester platform and a server platform. The process involves receiving a request from the requestor platform referring to a system resource and specifying a requested lease period, permitting shared access to the system resource for a lease period, sending a return call to the requestor platform advising of the lease period, and deallocating the system resource when the lease period expires.

Methods, apparatus, and product for distributed garbage collection

A data retrieval system is described. The system includes a data server, at least one data retrieval client, a co-presence server and at elast one downloadable co-presence client. The data server retrieves at least one data object from among a plurality of data objects stored in a data repository. The data retrieval client requests at least one data object from the data server. The co-presence server includes a virtual place generator which generates one virtual place per data object retrieved from the data server and an associator which associates each virtual place with its data object once its data object is accessed. The downloadable co-presence client is operative with the data retrieval client and communicates with the co-presence server. Each co-presence client includes an object associator which associates a data object received from the co-presence server with one of the at least one virtual places in the co-presence server.

Co-presence data retrieval system

A distributed object oriented computer system that has two classes of object references: strong references and weak references. Weak references (or pointers) allow users to refer to an object, but does not prevent the object manager from deleting the object. A weak object reference can be converted into a strong object reference by execution of a "MakeStrong" operation, which generates a strong reference, and then deleting the weak reference. A strong object reference can be converted into a weak object reference by execution of a "MakeWeak" operation, which returns a weak reference to the object referred to in the operation's argument, and then deleting the strong reference. When an object no longer has any outstanding strong object references, deletion of the object is enabled. In another aspect of the invention, a portion of the computer's memory is set aside for a primary linker cache and a secondary linker image cache. Linker images, generated while loading programs for execution, are stored in the primary and secondary linker caches. Each linker image in the primary linker cache has strong object references to objects included in corresponding ones of the loaded programs, and each linker image in the secondary linker cache has weak object references to objects included in corresponding ones of the loaded programs.

System amd method for distributed object resource management

A method and system in a data processing system for the establishment of relationships between reference objects in an object oriented environment and an associated data object residing outside an object oriented environment. A data object within an application outside an object oriented environment is identified. Multiple reference objects within an oriented environment are then established. Each reference object has a unique identifier and is associated with one of multiple users. Each reference object is associated with the identified data object so that multiple users may concurrently access the data object utilizing an associated reference object. The associated data object may then be modified in response to a modification of any reference object. Similarly, the reference objects may be modified in response to a modification of the associated data object.

Method and system in a data processing system for the enhancement of relationships between reference objects in an object oriented environment and a data object outside an object oriented environment

Kenneth D. Yates

Papers

Method and system in a data processing system for the enhancement of relationships between reference objects in an object oriented environment and a data object outside an object oriented environment