Gemstone Systems, Inc.

Vmware, Inc.

Pivotal Software, Inc.

Robert F Bretl

David J Monnie

Eric J Zoerner

Ramachandran Venkatesh

David Whitlock

Bruce Schuchardt

Allen J Otis

Darrel Scott Schneider

Martin R McClure

Michael A Nastos

A shared object space in a computer system provides synchronized access to data objects accessible to a plurality of concurrently running applications in the computer system. The shared object space is allocated a portion of memory of the computer system and concurrently running applications are able to connect to the shared object space. The shared object space restricts simultaneous access to data objects by the concurrently running applications by associating locks with the data objects.

Object synchronization in shared object space

The present invention relates to a system for monitoring an object space shared among plural applications. Objects stored in the shared space are registered for monitoring and the system receives data related to the registered objects that can be utilized to perform statistical analysis, for example, relating to the overall health of the applications.

Object monitoring system in shared object space

A system for synchronizing shared objects among multiple applications includes a shared object space in which the shared objects are stored and accessible to the multiple applications. In order to properly control access to shared objects, each shared object includes a header that is capable of storing an identification of a sole application that is the only application currently accessing the shared object or a reference into a lock table that stores lock nodes corresponding to a number of applications that are currently seeking access to the shared object.

A system for sharing listeners monitoring events occurring in objects shared by multiple applications each running inside its own virtual machine in a computer system.

Shared listeners in shared object space

A system for sharing queues among multiple applications each running inside its own virtual machine.

Shared queues in shared object space

Software and a method selectively apply a pessimistic concurrency control for each database update that conflicts with another database update. The method includes determining whether a database update conflicts with another database update, applying an optimistic concurrency control for each database update that does not conflict with another database update, and applying a pessimistic concurrency control for each database update that does conflict with another database update. This provides a selective locking concurrency control that selectively applies transaction serialization and locking only when transaction conflicts are detected. As a result, the selective locking concurrency control avoids livelock transaction failures and provides deterministic transaction completion without the computational expense of a conventional pessimistic concurrency control.

Selective pessimistic locking for a concurrently updateable database

A queue data structure is stored on a computer-readable medium to represent a queue or list. The data structure includes a head pointer that points to the last or most recent list element to have been removed from the queue, and a tail pointer that points to the most recently added list element in the queue. The head pointer and tail pointer may be implemented as separate objects. The queue data structure is applicable to computer arts such as transactional database management. The queue data structure can prevent concurrency conflicts that could otherwise occur when an object modified in one transaction (e.g. by one user) is modified by another concurrent transaction (e.g. by another user).

Object queues with concurrent updating

A virtual machine computer includes multiple threads and can support multiple simultaneous workspaces. Within each workspace, multiple threads are able to access objects simultaneously. Threads are orthogonal to workspaces so that threads are not locked to particular workspaces, workspaces are not locked to particular threads, and the sizes of the workspaces are configurable to the requirements of the transactions within the workspaces. Such a virtual machine may be utilized in a variety of applications including transactional database applications in which multiple users have access to information (e.g., objects) in one or more shared databases. Such applications typically require that data transactions involving the objects in the shared database be performed reliably so as to maintain the integrity of the objects, which are sometimes called persistent objects.

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Portland, OR, United States of America

Robert F Bretl