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Queuing Multiple Calls of the Same Application

IP.com Disclosure Number: IPCOM000038836D
Original Publication Date: 1987-Mar-01
Included in the Prior Art Database: 2005-Feb-01
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Havel, EA: AUTHOR [+2]

Abstract

A method is described for enabling multiple calls to be executed against the same application in a multitasking environment. In a multitasking environment, it is possible for two or more invocations of a program to be made before completion of the first invocation. Without planning for this possibility, unpredictable results would result. One solution would be to return a bad return code to an application that attempts to invoke an application already processing. This would make it necessary for the application programmer to handle the collision and retry. A better solution would be to make the application reentrant. Reentrant applications allow multiple invocations to process without adverse effect. A work request pool and queue of work space would be necessary.

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Queuing Multiple Calls of the Same Application

A method is described for enabling multiple calls to be executed against the same application in a multitasking environment. In a multitasking environment, it is possible for two or more invocations of a program to be made before completion of the first invocation. Without planning for this possibility, unpredictable results would result. One solution would be to return a bad return code to an application that attempts to invoke an application already processing. This would make it necessary for the application programmer to handle the collision and retry. A better solution would be to make the application reentrant. Reentrant applications allow multiple invocations to process without adverse effect. A work request pool and queue of work space would be necessary. This solution would require additional memory and application code to process the additional request. The method presented involves temporarily suspending an application program that attempts to reinvoke an application. The application is suspended until the application completes the initial invocation. A suspend and resume function is necessary to enable this solution. The <Pause> system call causes an application to suspend execution until the next clock cycle. By consistently checking to see if the application is already executing and invoking the pause system call, the application can effectively be suspended until the required application is no longer a...