The value of the MULTITASKING-INTERVAL attribute determines how often the AVM internally filters events (messages) between itself and other Windows applications. As the AVM filters these events more often, it executes procedures less efficiently, but allows other windows applications more opportunity to execute. Adjusting the internal event filter is particularly useful during background processing, such as report generation.
The default value, zero, tells the AVM never to filter events internally, giving ABL applications maximum access to execution resources. This is perfectly adequate for interactive ABL applications that block for input often, giving other applications enough opportunity to execute.
For values greater than zero, the lower the value, the more often the AVM internally filters events, giving other applications greater opportunity to execute, but slowing down the AVM execution. However, similar to a TRUE value for the IMMEDIATE-DISPLAY attribute, low non-zero values also cause the AVM to refresh the display more often, potentially providing crisper display interaction. Low non-zero values also provide better interoperability with other applications, for example, using Dynamic Data Exchange (DDE).
The maximum value you can set is 9999. In general, set this attribute greater than zero only for code segments that perform lengthy background operations, and reset it to zero before the application blocks for interactive input (for example, executes a WAIT-FOR or UPDATE statement). This attribute provides the same functionality as the MultitaskingInterval parameter in the current environment, which might be the Registry (Windows only) or an initialization file. For more information on environments, see the chapter on user interface environments in OpenEdge Deployment: Managing ABL Applications.
