Method and apparatus providing optimistic locking of shared computer resources

摘要

Techniques for concurrent access to a resource object, such as a database object, include generating a lock data structure for a particular resource object. The lock data structure includes data values for a resource object identification, a lock type, and a version number. The version number is related to a number of changes to the resource object since the lock data structure was generated. By carrying a lock version number in a lock data structure managed by a lock manager, improved optimistic locking is provided in a database. In particular, the approach enables introduction of optimistic locking to a legacy database without requiring burdensome changes to a database table schema.

主权项

1. A method for managing access to a resource, the method comprising the computer-implemented steps of:
receiving a request for access to a particular resource to make an update to the particular resource; generating a lock associated with the particular resource, wherein the lock comprises a first value for a version number that is equal to a value for a version number associated with the particular resource and is related to whether the particular resource has been updated, and wherein the first value for the version number is stored in the lock rather than in a database including data and attributes of the particular resource; receiving a request to commit the update to the particular resource, wherein the request includes the first value; determining whether a current value for the version number in the lock and associated with the particular resource is equal to the first value for the version number received in the request to commit the update; and in response to determining that the current value for the version number is equal to the first value for the version number, converting the lock to a different type of lock and committing the update; wherein the method is performed by a system comprising a processor.