Procedure

   void gfclrh_c ( void ) 

Abstract

 
   Clear the interrupt signal handler status, so that future calls
   to gfbail_c will indicate no interrupt was received. 
 

Required_Reading

 
   GF
 

Keywords

 
   GEOMETRY
   SEARCH
   UTILITY 
 

Brief_I/O

 
   None. This routine operates by side effects; see Particulars
   below.
 

Detailed_Input

 
   None. 
 

Detailed_Output

 
   None. 
 

Parameters

 
   None. 
 

Exceptions

 
   Error free.

Files

 
   None. 
 

Particulars

  
   This routine clears the interrupt signal handler status maintained
   by the GF subsystem. Calling this routine causes the GF interrupt
   signal receipt indicator function gfbail_c to return SPICEFALSE
   until the next interrupt signal is received by a signal handler
   established by the GF system.

   User applications that use default GF interrupt handling should call
   this routine after processing an interrupt signal.

Examples

 
   1) The code fragment below is from an example program in
      the header of gfocce_c. The code includes a search,
      a call to gfbail_c, which is made to determine whether
      an interrupt signal was received, and a call to 
      gfclrh_c to clear the interrupt signal status.

            ...

            /.
            Turn on interrupt handling and progress reporting.
            ./
            bail = SPICETRUE;
            rpt  = SPICETRUE;

            /.
            Perform the search.
            ./
            gfocce_c ( "ANY",                            
                       "MOON",     "ellipsoid",  "IAU_MOON", 
                       "SUN",      "ellipsoid",  "IAU_SUN",  
                       "LT",       "EARTH",      CNVTOL,    
                       gfstep_c,   gfrefn_c,     rpt,       
                       gfrepi_c,   gfrepu_c,     gfrepf_c, 
                       bail,       gfbail_c,     &cnfine,   
                       &result                              );


            if ( gfbail_c() ) 
            {
               /.
               Clear the CSPICE interrupt indication. This is
               an essential step for programs that continue
               running after an interrupt; gfbail_c will
               continue to return SPICETRUE until this step
               has been performed.
               ./
               gfclrh_c();


               /.
               We've trapped an interrupt signal. In a realistic
               application, the program would continue operation
               from this point. In this simple example, we simply
               display a message and quit.
               ./
               printf ( "\nSearch was interrupted.\n\nThis message "
                        "was written after an interrupt signal\n"
                        "was trapped. By default, the program "
                        "would have terminated \nbefore this message "
                        "could be written.\n\n"                       );
            }
            else
            

            ...

Restrictions

 
   This routine has no visible effect on operation of user applications
   unless GF interrupt handling is enabled and gfbail_c is used as
   the interrupt signal receipt indicator.
 

Literature_References

 
   None. 
 

Author_and_Institution

 
   N.J. Bachman   (JPL) 
   L.S. Elson     (JPL) 
 

Version

 
   -CSPICE Version 1.0.0, 05-FEB-2009 (NJB) (LSE)

Index_Entries

 
   GF clear interrupt signal status
 

Link to routine gfclrh_c source file gfclrh_c.c