DSS2 — DDM Overview: Steps to Create a Region Specification

If the Set Range Bounds service is not called for a given dimension of a region, or the Commit Region Modifications service is not called after the Set Range Bounds service has been invoked for every dimension of that region, then the region will contain one or more dimensions that do not have ranges set, and there will be no way to use this region meaningfully. If some of a region's dimensions do not have ranges, then there is no way to determine whether or not the region overlaps with other regions. The text needs to make clear that the creation of a region specification is accomplished using a sequence of service calls, and all of these service calls must be invoked successfully, in sequence, in order to successfully create a region specification . The following clarifying text is suggested:

If a federate invokes the Create Region service but does not subsequently successfully invoke the Set Range Bounds service for every dimension in the region, followed by a successful invocation of the Commit Region Modifications service for the region, then the federate has not created a region specification. In particular:

· If a federate invokes the Create Region service, followed by an invocation of the Set Range Bounds service for none or some, but not for all, of the dimensions that were specified when the region was created, followed by an invocation of the Commit Region Modifications service for that region, the Commit Region Modifications service shall throw the "Invalid region" exception, because each region designator that is passed to the Commit Region Modifications service is required to have had the Set Range Bounds service invoked at least once for all of its dimensions. The effects of the Set Range Bounds service invocations that were made, if any, are still pending. They will take affect if and when the Set Range Bounds service has been invoked at least once for all of the dimensions of the region, followed by the invocation of the Commit Region Modifications service for that region.

· If a federate invokes the Create Region service, followed by at least one Set Range Bounds service invocation for every one of the dimensions that were specified when the region was created, but does not invoke the Commit Region Modifications service, the region continues to be only a region template, but not a region specification. The effects of the Set Range Bounds service invocations are still pending and will take effect if and when the Commit Region Modifications service is successfully invoked for that region.

The effects of invocation of the Set Range Bounds service for a given region (template or specification) will remain pending until the Commit Region Modifications service is subsequently invoked for that region. If a federate invokes the Set Range Bounds service repeatedly for a given dimension of a given region before invoking the Commit Region Modifications service for that region, the range values provided in the most recent invocation of the Set Range Bounds service will become the range values for that dimension of that region specification.

Add the suggested clarifying text.