Abstract: An object oriented message passing system for transferring messages between a client task and a server task comprises an object database, an object management unit, a message transaction unit, and a locking unit. The object management unit creates a port object and one or more associated message objects. The message transaction unit matches a send message request issued by a client task with an acceptance function or with a receive message request issued by a server task. In response to a send message request, the message transaction unit creates a send message control block. In response to a receive message request, the message transaction unit creates a delivery message control block if the receive message request matches the send message control block, or creates a receive message control block if the receive message request does not match the send message control block.

Abstract: In a computer including at least one caller adapted to request access to a storage media, the storage media being organized according to one of at least one file system format, a system for handling requests for access to the storage media.

Abstract: A hierarchical filing system provides a cataloging of data stored in various locations within a memory device. An upside-down tree type structure provides a downwardly expanding cataloging structure wherein directories provide for further branchings. A branching from a directory is terminated when a file is reached. Each directory is assigned a unique directory identifier value. Then, each file or directory is coupled with the directory identifier value of its parent to provide the interconnection necessary to form the cataloging structure. The complete cataloging structure is organized in the leaf nodes of a B-Tree structure and distributed in an ascending order of the key values to provide a systematic search for a given key. Each file is capable of storing a predetermined number of location description information when data is segmented into non-contiguous segments in memory. A file extents record is used to maintain record of the further segmentation.