Procedure

     DWPOOL ( Delete watch from kernel pool )

     ENTRY DWPOOL ( AGENT )

Abstract

     Delete a name from the list of agents to notify whenever a member
     of a list of kernel variables is updated.

Required_Reading

     KERNEL

Keywords

     CONSTANTS
     FILES

Declarations

    CHARACTER*(*)         AGENT

Brief_I/O

     VARIABLE  I/O  DESCRIPTION
     --------  ---  --------------------------------------------------
     AGENT      I   The name of an agent to be notified after updates.

Detailed_Input

     AGENT    is any agent name that has previously been associated
              with a kernel pool watch via a call to SWPOOL. The
              agent name will be deleted from the notification list
              of every watched kernel variable.

              Watched variables whose notification lists become
              empty will be deleted.

Detailed_Output

     None.

Parameters

     None.

Exceptions

     1)  It's not an error to delete a non-existent agent---one
         that is not present in the watcher system. A call to
         delete a non-existent agent has no effect on the state
         of the watcher system.

     2)  If an attempt is made to delete an agent that
         has an unchecked update, the error SPICE(UPDATEPENDING)
         is signaled.

Files

     None.

Particulars

     Kernel pool watches are a limited resource; the ability
     to delete watches when they're no longer needed is essential
     to allow programs that make heavy use of kernel pool watches
     to run for extended periods.

Examples

     Suppose that you have an application subroutine, MYTASK, that
     needs to access a large data set in the kernel pool. If this
     data could be kept in local storage and kernel pool queries
     performed only when the data in the kernel pool has been
     updated, the routine can perform much more efficiently.

     If at some point the local stored data no longer need to be
     watched---for example, if they're removed from the local
     buffer to make room for other data---the watch set by the
     agent 'MYTASK' on those data can be deleted via the call

        CALL DWPOOL ( 'MYTASK' )

Restrictions

     1)  It is recommended that watches be deleted only by
         routines that established them.

Literature_References

     None.

Author_and_Institution

     N.J. Bachman       (JPL)
     J. Diaz del Rio    (ODC Space)
     B.V. Semenov       (JPL)

Version

    SPICELIB Version 1.1.1, 17-AUG-2021 (JDR)

        Edited the header to comply with NAIF standard.

    SPICELIB Version 1.1.0, 11-SEP-2013 (BVS)

        Updated to increment POOL state counter. Updated description
        of the exception 1).

    SPICELIB Version 1.0.0, 19-MAR-2009 (NJB)