GPSHDF - Set Shell Deferral State

Purpose

Use GPSHDF to set the shell deferral mode and the update notification mode.

A shell deferral mode set to 2=DEFERRED controls whether the following workstation control subroutines cause the graPHIGS API to send buffered requests to the nucleus which contains the workstation:

A shell deferral mode set to 3=DEFERRED_PLUS_MSGS controls whether the following subroutines cause the graPHIGS API to send buffered requests to the nucleus:

When the shell deferral mode is set to 1=FLUSH (default), each of the above subroutines results in sending buffered API requests to the nucleus. When the shell deferral mode is set to 2=DEFERRED or 3=DEFERRED_PLUS_MSGS , the graPHIGS API suppresses this automatic initiation for the specified subroutines. The application can use the Synchronize (GPSYNC) subroutine explicitly to send a buffered request to the nucleus. However, there are other graPHIGS API subroutines that the application has no control over that implicitly cause the API buffered requests to be sent to the nucleus. For information about buffered requests being sent to the nucleus, see The graPHIGS Programming Interface: Understanding Concepts

The update notification mode controls whether or not the graPHIGS API notifies the application about the completion of an update process initiated by the Redraw All Structures (GPRAST) or the Update Workstation (GPUPWS) subroutine.

When the update notification mode is set to 1=NO (default), the graPHIGS API does not notify the application when the graPHIGS API completes the update process. The nucleus ensures that the update process is completed without any intermediate interruption but the application cannot know when it has completed. When the update notification mode is 2=YES , the application is asynchronously notified by an Update Completion Event that the graPHIGS API completed the update process. For information about Update Completion Events, see The graPHIGS Programming Interface: Technical Reference

Note:

The Update Completion Event is generated even for the Update Workstation subroutine with regeneration flag 1=POSTPONE In this case, the event is generated immediately after the Update Workstation request is processed by the nucleus and it may contain a display status of 2=DEFERRED

Parameters