rom/dos/findsegment.c

   1 /*
   2     Copyright © 1995-2016, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     Desc: Find a resident segment.
   6     Lang: english
   7 */
   8
   9 #include <aros/debug.h>
  10 #include "dos_intern.h"
  11
  12 /*****************************************************************************
  13
  14     NAME */
  15 #include <dos/dosextens.h>
  16 #include <proto/dos.h>
  17
  18         AROS_LH3(struct Segment *, FindSegment,
  19
  20 /*  SYNOPSIS */
  21         AROS_LHA(CONST_STRPTR    , name, D1),
  22         AROS_LHA(struct Segment *, seg, D2),
  23         AROS_LHA(LONG            , system, D3),
  24
  25 /*  LOCATION */
  26         struct DosLibrary *, DOSBase, 130, Dos)
  27
  28 /*  FUNCTION
  29         Search for a resident segment by name and type (system or user).
  30         The first segment that exactly matches the name and type will be
  31         returned. The name is case insensitive. If the system argument is
  32         non-zero, only system segments will be returned (i.e. those that
  33         have a negative seg_UC value); if zero, only user segments will
  34         be returned (i.e. those with a non-negative seg_UC value).
  35
  36         You can continue searching for multiple segments that share the
  37         same name and type by specifying the last returned segment as
  38         the seg argument.
  39
  40         FindSegment() does no locking of the segment list. You should
  41         lock the list by calling Forbid() before calling FindSegment(),
  42         and unlock the list by calling Permit() once you have finished
  43         calling FindSegment().
  44
  45         If you wish to prevent a user segment from being unloaded, you
  46         must increment its seg_UC value before unlocking the list. Once
  47         finished with the segment, you must decrement its seg_UC value
  48         under Forbid()/Permit() protection. The seg_UC value of system
  49         segments should never be altered.
  50
  51     INPUTS
  52         name - Name of the segment to search for.
  53         seg  - Start search from this point.
  54         system - Search for a system segment.
  55
  56     RESULT
  57         A matching segment, or NULL.
  58
  59     NOTES
  60
  61     EXAMPLE
  62
  63     BUGS
  64
  65     SEE ALSO
  66         AddSegment(), RemSegment()
  67
  68     INTERNALS
  69
  70 *****************************************************************************/
  71 {
  72     AROS_LIBFUNC_INIT
  73
  74     struct DosInfo *dinf = BADDR(DOSBase->dl_Root->rn_Info);
  75
  76     /* Segment seg was the last match, let's start from the next one */
  77     if( seg != NULL )
  78         seg = BADDR(seg->seg_Next);
  79     else
  80         seg = BADDR(dinf->di_ResList);
  81
  82     while( seg != NULL )
  83     {
  84         D(bug("[FindSegment] Checking segment '%s'\n",
  85             AROS_BSTR_ADDR(MKBADDR(&seg->seg_Name[0]))));
  86         if
  87         (
  88             ((system && seg->seg_UC < 0) || (!system && seg->seg_UC >= 0)) &&
  89             (Stricmp( name, AROS_BSTR_ADDR(MKBADDR(&seg->seg_Name[0]))) == 0)
  90         )
  91         {
  92                 /* We have a matching segment */
  93                 return seg;
  94         }
  95         seg = BADDR(seg->seg_Next);
  96     }
  97
  98     return NULL;
  99     AROS_LIBFUNC_EXIT
 100 } /* FindSegment */