Abstract: A storage manager located between a plurality of requesting applications and a memory shared between the applications, has: a receiving unit for receiving a present memory access request from a first of said plurality of requesting applications; an accessing unit for accessing statistical data, the data based on collected values of sizes of initial free areas from prior memory access requests from the first requesting application; and a setting unit for setting a value of an initial free area for use by the present memory access request based on the accessed statistical data.

Abstract: Timer objects in an event driven data processing system define expiring times at which a timer event will be generated to trigger data processing actions. According to the invention, such timer objects are managed by, in response to definition of each timer object, storing each said object in secondary storage and, if its expiring time occurs within a predetermined interval, also storing each such timer object in main memory of the data processing system. The expiry times of timer objects are periodically scanned and any currently to expire within the predetermined interval are stored in main memory.

Abstract: A computer data storage management system for allocating and releasing data storage memory in response to requests from application programs. The data storage is organized as a plurality of subpools, each subpool containing a control area 21 and a plurality of pages of memory 122, 222, 322 divided into fixed length cells. Free memory cells contain, within the area used for data storage in non-free cells, an indication 182, 183, 382-384. The presence of this indication is checked prior to the allocation of cells and the absence of the indicator prior to release of the cells.

Abstract: A releasable tube coupling comprises a body providing a housing in which an annular seal and clamping ring are located and secured by a retainer and, a releaser slidably supported by the retainer for limited axial movement relative to the housing. The seal is of generally Z-section having outer and inner flanges connected by an inclined web convergent towards the inside of the housing. The clamping ring is mounted into the seal and has a plurality of spaced apart radially inwardly directed inclined teeth which overlie the web on the inner face of the seal for engagement with the outer surface of a tube received within the housing to retain the tube in the housing. The teeth are displaced away from the tube to permit axial withdrawal the tube on inwards movement of the releaser which acts on the teeth through the seal web.