Index of Functions: A B C D E F G H I J K L M N O P Q R S T U V W X
Index Page kclear_c

Table of contents

Procedure Abstract Required_Reading Keywords Brief_I/O Detailed_Input | Detailed_Output Parameters Exceptions Files Particulars Examples | Restrictions Literature_References Author_and_Institution Version Index_Entries

#### Procedure

       kclear_c ( Keeper clear )

       void kclear_c ( void )

#### Abstract

       Clear the KEEPER subsystem: unload all kernels, clear the kernel
       pool, and re-initialize the subsystem. Existing watches on kernel
       variables are retained.

#### Required_Reading

       None.

#### Keywords

       KERNEL

#### Brief_I/O

       VARIABLE  I/O  DESCRIPTION
       --------  ---  --------------------------------------------------
       None.

#### Detailed_Input

       None. This routine operates by side effects. See -Particulars
       below.

#### Detailed_Output

       None.

#### Parameters

       None.

#### Exceptions

       1)  If an error occurs when setting a kernel pool watch or
           checking watched variables, the error is signaled by a routine
           in the call tree of this routine.

#### Files

       See -Particulars.

#### Particulars

       This entry point allows you re-initialize the KEEPER system with
       a single call. The KEEPER system is the kernel management system
       underlying the set of CSPICE APIs

          furnsh_c
          ktotal_c
          kdata_c
          kinfo_c
          kclear_c
          unload_c

       This routine unloads all kernels from their kernel-type-specific
       kernel management subsystems (SPKBSR, CKBSR, etc.), clears the
       kernel pool, clears KEEPER's internal file database, and re-sets
       the watch status for the kernel variables used to load kernels
       via meta-kernels. As a side effect of clearing the kernel pool,
       all watched variables are marked as updated. Note that clearing
       the kernel pool does not delete watchers.

       This capability, though implemented in Fortran, is particularly
       relevant to SPICE implementations such as Icy, for which the
       state of the KEEPER system persists after any Icy-based IDL
       script is run. Successive runs of Icy-based scripts may perform
       in unexpected ways when scripts access data loaded during runs of
       previous scripts.

       Cleaning up after such programs using explicit unload_c commands is
       tedious and error-prone. One call to this routine sets the
       KEEPER system to its initial state, preventing unintentional
       interaction between scripts via KEEPER's state.

#### Examples

       The numerical results shown for this example may differ across
       platforms. The results depend on the SPICE kernels used as
       input, the compiler and supporting libraries, and the machine
       specific arithmetic implementation.

       1) Load a meta-kernel containing three kernels, and count the
          number of files in the kernel pool before and after calling
          cspice_kclear.

          Use the meta-kernel shown below to load the required SPICE
          kernels.

             KPL/MK

             File name: kclear_ex1.tm

             This meta-kernel is intended to support operation of SPICE
             example programs. The kernels shown here should not be
             assumed to contain adequate or correct versions of data
             required by SPICE-based user applications.

             In order for an application to use this meta-kernel, the
             kernels referenced here must be present in the user's
             current working directory.

             The names and contents of the kernels referenced
             by this meta-kernel are as follows:

                File name                     Contents
                ---------                     --------
                de421.bsp                     Planetary ephemeris
                pck00008.tpc                  Planet orientation and
                                              radii
                naif0009.tls                  Leapseconds

             \begindata

                KERNELS_TO_LOAD = ( 'de421.bsp',
                                    'pck00008.tpc',
                                    'naif0009.tls'  )

             \begintext

             End of meta-kernel

          Example code begins here.

          /.
             Program kclear_ex1
          ./
          #include <stdio.h>
          #include "SpiceUsr.h"

          SpiceInt        count;

          int main()
          {
             /.
             Load the meta kernel.
             ./
             furnsh_c( "kclear_ex1.tm" );

             /.
             Count the number of loaded kernel files.
             ./
             ktotal_c ( "ALL", &count );

             printf ( "Count of loaded kernels before "
                      "kclear_c call: %d\n", count );

             /.
             Clear the KEEPER system, retrieve the number of loaded
             after the clear.
             ./
             kclear_c ( );

             ktotal_c ( "ALL", &count );

             printf ( "Count of loaded kernels after "
                      "kclear_c call : %d\n", count );

          }

          When this program was executed on a Mac/Intel/cc/64-bit
          platform, the output was:

          Count of loaded kernels before kclear_c call: 4
          Count of loaded kernels after kclear_c call : 0

#### Restrictions

       1)  Calling this routine will wipe out any kernel pool data
           inserted via the CSPICE API routines to put data into the
           kernel pool (pcpool_c, pdpool_c and pipool_c).

#### Literature_References

       None.

#### Author_and_Institution

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

#### Version

       -CSPICE Version 1.0.2, 10-AUG-2021 (JDR)

           Edited -Examples section to comply with NAIF standard. Added
           complete example.

           Improved -Restrictions section.

       -CSPICE Version 1.0.1, 01-JUL-2014 (NJB)

           The header -Particulars section was updated to more
           completely describe the effect of this routine on
           kernel pool watchers. Header section order was corrected.

       -CSPICE Version 1.0.0, 15-NOV-2006 (NJB)

#### Index_Entries

       Re-initialize the keeper system
       Clear the keeper system
       Unload all kernels

#### Link to routine kclear_c source file kclear_c.c

    Fri Dec 31 18:41:08 2021