International Business Machines Corporation

William Daniel Wigger

David Blair Gilgen

Erik John Burckart

Craig Andrew Lanzen

Embodiments of the present invention address deficiencies of the art in respect to threading model switching between asynchronous I/O and synchronous I/O models and provide a novel and non-obvious method, system and computer program product for autonomic threading model switching based upon I/O request types. In one embodiment, a method for autonomic threading model switching based upon I/O request types can be provided. The method can include selectably activating and de-activating a blocking I/O threading model according to a volume of received and completed blocking I/O requests.

Autonomic threading model switch based on input/output request type

Under the present invention, when a TCS receives a data command (e.g., a read or write command) pursuant to a communication session between the TCS and an application, it will first request permission from a permission system to execute the data command. By applying a set of rules to a setting of a state variable associated with the TCS, the permission system will determine whether to grant the permission. If so, the TCS will execute the data command and change the setting of the state variable. If a close command is later received by the TCS to close the communication session, permission will once again be requested from the permission system, which will again apply a set of rules to the current setting of the state variable to determine if the session can be safely closed.

Method, system and program product for closing a communication session with outstanding data commands on a transport communication system

The present invention is a method, system and apparatus for memory leak detection and reporting. In a preferred method of the invention, allocated ones of resources in a resource pool can be time stamped upon allocation and calling code segments receiving the allocated resources can be identified. Memory leaks can be detected by inspecting individual timestamps for the allocated resources to determine whether the allocated resources have become overly idle. Notably, the identifying step can include the step of retrieving identities for individual ones of the calling code segments from an associated calling stack when the individual ones of the calling code segments acquire one of the allocated resources. In any case, for each allocated resource determined to have become overly idle, an identity of a corresponding one of the calling code segments can be reported.

Fast detection of the origins of memory leaks when using pooled resources

An invention is disclosed for a computer software timeout algorithm that reduces the amount of list manipulation needed to satisfy system or network requirements for scheduling and cancelling timeout requests to determine whether the expiration time has been reached for execution of an input/output (I/O) request, thereby requiring action to cancel the I/O operation if it has not yet been completed.

Timeout request scheduling using grouping and nonsynchronized processing to enhance performance

A method for filtering data packets through computers on the Internet that allows a computer to determine whether an incoming numbered list is present in a numbered list data set. The present invention comprises an Array Creation Program (ACP) and an Array Matching Program (AMP). The ACP creates a plurality of arrays from the numbered list data set. The values of the array fields are based on the numbers in the numbered lists. The AMP analyzes the numbers in the incoming numbered list to determine the hexadecimal values in the array fields associated with the numbers in the incoming numbered list. The AMP uses a counter to process the numbers in the incoming numbered list. If the counter becomes zero, then the incoming numbered list is not present in the numbered list data set.

Fast searching of list for IP filtering

A technique for combining a meta data file and Java source code to dynamically create Java classes and JavaBeans. This technique enables creating objects and JavaBeans in a new, more flexible manner. An approach similar to, but different from, existing macro definition and expansion is used. According to the present invention, placeholders for parameter values are specified in the main source code file, and the values to be substituted for these placeholders are contained in an auxilliary file, referred to as a &ldquo;meta file&rdquo; or &ldquo;meta data file&rdquo;. By isolating the parameter values outside the source code file in this manner, the values are much easier to change. The change does not affect the source code file itself. Instead, the change is reflected in a new file created during the expansion process. This approach enables an end-user to easily specify objects to be created, and/or the instance data to be used for creating a particular object (i.e. the values to be used for the parameters), without having to know Java code syntax and without having to obtain write permissions to the Java source code. The approach of the present invention also allows a particular macro to be used in different ways throughout a source code file. A particular macro name can be referenced multiple times in the source code file, with the ability to specify substitution of a selectable subset of the parameter values where that subset may change from one reference to another. In addition, a macro name can be specified multiple times in the meta file of the present invention, with parameter values that may change from one specification to another. Optionally, a conditional expansion feature may be used. The technique of the present invention may be used advantageously with object-oriented languages other than the Java programming language.

Growing community of inventors

Durham, NC, United States of America

William Daniel Wigger