XCF invokes a member's status user routine by scheduling a local SRB to the member's primary address space. You are responsible for writing the status user routine, which can do the following:

• Determine if the member's initialization is complete. A member might issue IXCJOIN and its status user routine could get control before IXCJOIN returns to the caller. To determine if the member's initialization is complete, the status user routine might examine a bit that the member sets on or off. The member might want its status user routine to automatically set a return code indicating that the member is operating normally, until the routine determines that initialization is complete.
• Determine whether XCF was checking for a status update missing (first call to the status user routine) or a status update resumed (subsequent call to the status user routine). The status user routine determines this by checking the SEPLSTCH field in IXCYSEPL. SEPLSTCH=SEUPDMIS means checking for status update missing; SEPLSTCH=SEUPDRES means checking for status update resumed.
• If this is the first call, determine if the member is no longer operating normally and whether XCF should broadcast a status change to the other members of the group. If this was not the first call, determine if the member is now operating normally. The status user routine might do one of the following to make this determination:
  • Access the member data value provided through IXCJOIN (SEPLMDAT in IXCYSEPL). The member data might contain addresses of control structures. The status user routine could check the control structures to determine if they are damaged. The control structures might also contain an indication of the member state or user state value for the member.
  • Examine a work queue to determine if the member missed its status update because there was no work to do.
• Take an appropriate action, such as:
  • Keep a count of how many times XCF invokes the status user routine within a particular time interval (for example, within one hour). From this, determine whether the member's status-checking interval should be modified.
  • If the status user routine determines that the member is not operating normally, it can post a task to do recovery for the member.
  • If the status user routine determines that the member is not operating normally, it can issue the SYMREC macro to create a symptom record with diagnostic data.
  • If recovery is not possible, the status user routine might insure that the member is stopped in the event other members are resuming the member's work.
  • Issue IXCMSGOX to provide another member with recovery data.
• Set the appropriate return code. The following summarizes what effect each return code has:
  • A return code of SEUPDRES indicates that the member is operating normally.
  • A return code of SEUPDMIS indicates that the member missed its status update.
  • A return code that matches the value in SEPLSTCH causes XCF to schedule the group user routines and notify them of a status change for that member (either a status update missing or a status update resumed).