| unload_c |
|
Table of contents
Procedureunload_c ( Unload a kernel ) void unload_c ( ConstSpiceChar * file ) AbstractUnload a SPICE kernel. Required_ReadingNone. KeywordsKERNEL Brief_I/OVARIABLE I/O DESCRIPTION -------- --- -------------------------------------------------- file I The name of a kernel to unload. Detailed_Input
file is the name of a file to unload. This file
should be one loaded through the interface furnsh_c.
If the file is not on the list of loaded kernels
no action is taken.
Note that if file is a meta-text kernel, all of
the files loaded as a result of loading the meta-text
kernel will be unloaded.
Detailed_OutputNone. ParametersNone. Exceptions
1) If the specified kernel is not on the list of loaded kernels
no action is taken.
2) If the `file' input string pointer is null, the error
SPICE(NULLPOINTER) is signaled.
3) If the `file' input string has zero length, the error
SPICE(EMPTYSTRING) is signaled.
FilesNone. Particulars
The call
unload_c ( file );
has the effect of "erasing" the last previous call:
furnsh_c ( file );
This interface allows you to unload binary and text kernels.
Moreover, if you used a meta-text kernel to set up your
working environment, you can unload all of the kernels loaded
through the meta-kernel by unloading the meta-kernel.
Unloading Text Kernels or Meta-Kernels
--------------------------------------
Part of the action of unloading text (or meta-text kernels) is
clearing the kernel pool and re-loading any kernels that were not in
the specified set of kernels to unload. Since loading of text
kernels is not a very fast process, unloading text kernels takes
considerably longer than unloading binary kernels. Moreover, since
the kernel pool is cleared, any kernel pool variables you have set
from your program by using one of the interfaces pcpool_c, pdpool_c,
pipool_c, or lmpool_c will be removed from the kernel pool. For
this reason, if you plan to use this feature in your program,
together with one of the routines specified above, you will need to
take special precautions to make sure kernel pool variables required
by your program do not inadvertently disappear.
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 with a PCK, an LSK and an SPK, and
separately, a text kernel and a binary PCK. Loop over the
loaded kernels, outputting file information for each of
them.
Then unload the text kernels, check that they have been
unloaded, and finally unload the meta-kernel.
Use the meta-kernel shown below to load the required SPICE
kernels.
KPL/MK
File name: unload_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
pck00009.tpc Planet orientation and
radii
naif0012.tls Leapseconds
\begindata
KERNELS_TO_LOAD = ( 'de421.bsp',
'naif0012.tls',
'pck00009.tpc' )
\begintext
End of meta-kernel
Use the PCK kernel below as the binary PCK required for the
example.
earth_latest_high_prec.bpc
Use the FK kernel below as the text kernel required for the
example.
RSSD0002.TF
Example code begins here.
/.
Program unload_ex1
./
#include <stdio.h>
#include "SpiceUsr.h"
int main( )
{
/.
Local constants.
./
#define FNAMLN 256
#define FTYPLN 33
#define SRCLEN 256
/.
Local variables.
./
SpiceChar file [FNAMLN];
SpiceChar filtyp [FTYPLN];
SpiceChar srcfil [SRCLEN];
SpiceInt count;
SpiceInt handle;
SpiceBoolean found;
/.
Load several kernel files.
./
furnsh_c ( "unload_ex1.tm" );
furnsh_c ( "RSSD0002.TF" );
furnsh_c ( "earth_latest_high_prec.bpc" );
/.
Count the number of loaded kernel files.
./
ktotal_c ( "ALL", &count );
printf( "The total number of kernels after final furnsh_c: %1d\n",
count );
printf( "\n" );
/.
Unload the text kernels.
./
ktotal_c ( "TEXT", &count );
printf( "\n" );
printf( "Unloading %1d text kernels...\n", count );
printf( "\n" );
while ( count > 0 )
{
kdata_c ( 0, "TEXT", FNAMLN, FTYPLN, SRCLEN,
file, filtyp, srcfil, &handle, &found );
/.
If the kernel is found in the pool, unload it.
./
if ( found )
{
unload_c ( file );
/.
Check if the file has been unloaded.
./
kinfo_c ( file, FTYPLN, SRCLEN, filtyp,
srcfil, &handle, &found );
if ( found )
{
printf( " Error" );
}
else
{
printf( " Success" );
}
printf( " unloading %s\n", file );
}
/.
Something is not working. Inform NAIF.
./
else
{
printf( " ERROR: No kernel found but ktotal_c returns %d\n",
count );
}
/.
Check if we have more text kernels to unload from
the kernel pool. Note that unloading a text kernel
or meta-kernel implies that the kernel pool is
cleared, and any kernel[s - 1] that were not to be
unloaded are re-loaded. Therefore the `count' value
changes, and the indexing of the files within the
kernel pool too.
./
ktotal_c ( "TEXT", &count );
}
ktotal_c ( "ALL", &count );
printf( " \n" );
printf( "The total number of kernels after unload_c calls: %1d\n",
count );
/.
Clear the KEEPER system, retrieve the number of loaded
after the clear.
./
unload_c ( "unload_ex1.tm" );
ktotal_c ( "ALL", &count );
printf( " \n" );
printf( "The total number of kernels after final unload_c: %1d\n",
count );
return ( 0 );
}
When this program was executed on a Mac/Intel/cc/64-bit
platform, the output was:
The total number of kernels after final furnsh_c: 6
Unloading 3 text kernels...
Success unloading naif0012.tls
Success unloading pck00009.tpc
Success unloading RSSD0002.TF
The total number of kernels after unload_c calls: 3
The total number of kernels after final unload_c: 1
Restrictions
1) See the note regarding the unloading of text and meta-text
kernels.
Literature_ReferencesNone. Author_and_InstitutionN.J. Bachman (JPL) J. Diaz del Rio (ODC Space) W.L. Taber (JPL) Version
-CSPICE Version 1.0.1, 03-AUG-2021 (JDR)
Edited the header to comply with NAIF standard.
Created complete code example from existing code fragments.
Re-ordered header sections.
-CSPICE Version 1.0.0, 01-SEP-1999 (NJB) (WLT)
Index_EntriesUnload a SPICE kernel |
Fri Dec 31 18:41:14 2021