What is an XCF Note Pad

An XCF note pad has the following:

A 32 byte name composed of four 8 byte sections
A 32 byte description
A 64 byte static information area
A note limit
A duplex preference
Protocols
A timestamp of when it was created

When creating a note pad, the application specifies the note pad name, the note pad description, the static note pad information, the desired number of notes, whether duplexing of the host note pad structure is desired, and various protocols that are to be applied to use of the note pad. The protocol choices include indications of whether:

The number of connections with update access is to be limited to one
Instance number comparisons are required when connectors update and delete notes
The connectors are responsible for setting the note tag values
The maximum note tag value is to be tracked by XCF

XCF provides a timestamp to indicate when the note pad was created. This timestamp can be used to identify a particular note pad instance.

XCF considers the note pad name, note limit, and duplex preference when choosing a structure to host the note pad. In general, the note pad name determines the set of structures to be considered, the duplex preference determines the order in which those structures are examined, and the first accessible structure that has space for the requested number of notes is chosen to host the note pad. However, note that the structure selection algorithms might vary according to the installed level of the XCF Note Pad Services. Furthermore, there are cases where XCF will move the note pad to a different structure.

Once created, an XCF note pad persists until it is explicitly deleted or fails. A note pad is explicitly deleted when:

A program issues the IXCNOTE macro to delete the note pad
The installation runs the XCF delete utility (IXCDELNP) to delete the note pad

A note pad fails and is implicitly deleted when:

A logically created note pad cannot be physically instantiated
The coupling facility containing the note pad fails (and there is no duplexed copy)
The coupling facility structure containing the note pad fails (and there is no duplexed copy)
The coupling facility structure containing the note pad is forced (deleted)
A sysplex outage occurs
The coupling facility containing the note pad is assigned to a different sysplex
The XCF note pad catalog fails

Since the note pad persists until it is deleted, the application must in general take responsibility for deleting the note pad when it is no longer needed. If the program does not explicitly delete the note pad, the application should document the circumstances under which the note pad is to be manually deleted by the installation with the XCF delete utility (IXCDELNP).

Note that deleting all the notes in the note pad does not cause the note pad to be deleted. The note pad simply continues to exist in an empty state with no notes. Nor does deleting all the connections to a note pad cause the note pad to be deleted. The note pad simply continues to exist with no connections.

The installation can use the z/OS® operator command DISPLAY XCF,NOTEPAD to get information about the note pads that are defined to the sysplex. See z/OS MVS System Commands for more information.

XCF issues message IXC472I when a note pad is created and issues message IXC471I if it is unable to create a note pad. Message IXC473I is issued when a note pad is deleted. See z/OS MVS System Messages, Vol 10 (IXC-IZP) for more information.