International Business Machines Corporation

Andrew Dean Wharmby

Anthony Philip Papageorgiou

Ann Eleanor Collins

Fraser P Bohm

Catherine Mary Moxey

Stephen P Bolton

Gillian Curwen

Jenny Jing He

Anthony Howard Phillips

Ian J Mitchell

Guo Qiang Li

Matthew Alexander Webster

John Simon Tilling

Samuel David Borman

Matthew Roy Kilner

Saket Rungta

Timothy E Preece

Holly Katherine Cummins

Sam D Borman

An apparatus, method and programming product for preventing event flooding in an event processing system, comprising, responsive to receiving monitored a activity data, analysing the monitored activity data to identify a first event value corresponding to a first event; determining whether the first event value has met a first threshold value of a set of threshold values; in response to determining the first event value has met a first threshold value of the set of threshold values, select a second threshold value of the set of threshold values; responsive to receiving the monitored activity data, analysing the monitored activity data to identify a second event value corresponding to a second event; responsive to determining that the second event value has exceeded the first threshold value and not exceeded the second threshold value, disregarding the second event.

Prevention of event flooding

A method, system, and computer program product that includes a processor cataloging a current resource definition and a current transaction state for the resource. The processor recovers the resource and a transaction state for the resource after an emergency restart, by utilizing the current resource definition and the current transaction state, wherein the recovering comprises recovering transactions of the resource. The processor completes or backs out of the transactions. The processor closes the resource and the processor recovers the resource by utilizing a global catalog.

Recovery of local resource

Operating an online transaction processing system to perform an application including a first module call by performing the following steps (not necessarily in the following order): (i) assigning a dedicated search path to the application, where the search path specifies an ordered set of location(s) for searching for module code, the set of location(s) includes at least a first dynamic module library and the first dynamic module library is ahead of any other locations which may be included in the dedicated search path; (ii) running the application through the transaction processing system; (iii) receiving the first module call, from the running of the application, specifying a requested module using a requested module name; and (iv) in response to the module call, locating the requested module based on the requested module name and the dedicated search path.

Application multi-versioning in a traditional language environment

Techniques for preventing event flooding in an event processing system, comprising: responsive to receiving, by an analysis component, monitored activity data, an analysis component for analyzing the monitored activity data, to determine a potential event; responsive to determining a potential event, an analysis component identifying a set of threshold values and determining whether the potential event has met a threshold value of the set of threshold values; responsive to a positive determination, an analysis component for determining if the met threshold value is an identical threshold value met by a previous potential event; and responsive to a second positive determination, a disregard component for disregarding the potential event.

A search facility is used to predict the impact of change on events detected in application logic, where the change may involve a computing resource used by or referenced by the application logic and/or by event detection logic. The search may be performed prior to making a change, in order to judge potential impact of the change, or after the change has been made. The search makes the prediction by evaluating semantics of conditions that specify when and/or and how an event will be detected at run-time.

Predicting the impact of change on events detected in application logic

A search facility is used to predict the impact of change on events detected in application logic, where the change may involve a computing resource used by or referenced by the application logic and/or by event detection logic. The search may be performed prior to making a change, in order to judge potential impact of the change, or after the change has been made. The search makes the prediction by evaluating semantics of conditions that specify when and/or how an event will be detected at run-time.

A method of memory management for a software application in execution in a computer system, the method comprising the steps of:

Memory management

A method, system and computer program product for batched remapping of virtual memory addresses for garbage collection in a large object area. A mapping from a table having a first set of virtual memory addresses and sizes of non-contiguous, page-aligned large objects in a large object area to a remapping table having a second set of virtual memory addresses is determined. In a single batch, a request is received that includes the second set of virtual addresses and requests a remapping of the large objects to the second set of virtual memory addresses. The second set of virtual memory addresses is validated, and the large objects are remapped to the second set of virtual memory addresses according to the request. The remapping results in a compaction so that the large objects are contiguous in the large object area. The remapping does not require copying data in physical memory.

Method, system and computer program product for batched virtual memory remapping for efficient garbage collection of large object areas

A system and associated method for optimizing a write barrier in garbage collection. The method marks a bit in a bitmap corresponding to a slot when the slot content is modified to refer to a new object. The method also logs the address of the slot when the object referred by the slot is updated. The method pops the address of the slot to clean from the log and clears the bit corresponding to the slot in the bitmap and when the object referred to by the slot is not already marked, marking said object and pushing its address to the mark stack. When the slot is located within an active object range, the method puts the address of the slot in a deferred log for a later processing.

System and method for optimizing write barrier in garbage collection

Method and system for managing a heap. A map is employed to indicate which areas of the heap are inaccessible to a program. Such areas constitute garbage which is potentially returnable to a data structure which identifies free storage available for reallocation to the program. By choosing map entries corresponding to portions of storage whose size is of the same order of magnitude as a predetermined minimum unit size for the data structure, a small map can be used. Such a map can be scanned more quickly than a larger map of higher granularity to identify only relatively larger areas of garbage for reallocation.

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Romsey, United Kingdom

Andrew Dean Wharmby