To invalidate copies of one or more data items that other users have in their local cache buffers, use IXLCACHE REQUEST=CROSS_INVAL. The system invalidates any copies of the specified data items that are in the local cache buffers of other users and deregisters interest in the data item for those users. (Your own copy of the data item is not invalidated.) Typically, you use the cross-invalidate function in a directory-only cache environment when you update data items on permanent storage. For a description of cross-invalidation, see Figure 1. The principles of invalidation are the same for a directory-only cache.

The request does not cause the specified data items to be deleted from the cache structure. Also, the system does not consider resources for a data item that is specified on the CROSS_INVAL request as eligible for reclaim.

If your protocol relies on external serialization, you need to hold a lock to serialize access to any data items. For serialization recommendations and sample scenarios that show how to establish serialization, see Serializing and Managing Access to Shared Data.