rom/oop/getattrbase.c

   1 /*
   2     Copyright © 1995-2007, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     Desc: OOP function OOP_GetAttrBase
   6     Lang: english
   7 */
   8
   9 #include "intern.h"
  10 #include "hash.h"
  11 /*****************************************************************************
  12
  13     NAME */
  14 #include <proto/exec.h>
  15 #include <exec/memory.h>
  16 #include <aros/libcall.h>
  17
  18 #include <aros/debug.h>
  19
  20         AROS_LH1(OOP_AttrBase, OOP_GetAttrBase,
  21
  22 /*  SYNOPSIS */
  23         AROS_LHA(CONST_STRPTR   , interfaceID, A0),
  24
  25 /*  LOCATION */
  26         struct Library *, OOPBase, 15, OOP)
  27
  28 /*  FUNCTION
  29         Maps a globally unique string interface ID into
  30         a numeric AttrBase ID that is unique on
  31         pr. machine basis. IMPORTANT: You MUST
  32         be sure that at least one class implementing
  33         specified interface is initialized at the time calling
  34         this function. This function is especially useful
  35         for a class to get AttrBases of the interfaces
  36         it implements.
  37
  38     INPUTS
  39         interfaceID     - globally unique interface identifier.
  40
  41     RESULT
  42         Numeric AttrBase that is unique for this machine.
  43         There are NO error conditions.
  44
  45     NOTES
  46
  47     EXAMPLE
  48
  49     BUGS
  50
  51     SEE ALSO
  52
  53     INTERNALS
  54
  55     HISTORY
  56
  57 ******************************************************************************/
  58 {
  59     AROS_LIBFUNC_INIT
  60
  61     /* Look up ID */
  62     struct iid_bucket *idb;
  63     struct HashTable *iidtable = GetOBase(OOPBase)->ob_IIDTable;
  64     ULONG base = (ULONG)-1;
  65
  66     EnterFunc(bug("OOP_GetAttrBase(interfaceID=%s)\n", interfaceID));
  67
  68     ObtainSemaphore(&GetOBase(OOPBase)->ob_IIDTableLock);
  69
  70
  71     /* Has ID allready been mapped to a numeric ID ? */
  72     idb = (struct iid_bucket *)iidtable->Lookup(iidtable, (IPTR)interfaceID, GetOBase(OOPBase));
  73     if (idb)
  74     {
  75
  76         /* If so, it has been stored in the hashtable, and we have
  77         ** to return the same numeric ID now.
  78         */
  79         if (idb->attrbase == (ULONG)-1)
  80         {
  81             /* The AttrBase has not yet been inited with ObtainAttrBase.
  82                I COULD init the attrbase now with the line below,
  83                but GetAttrBase() is only meant to work when
  84                attrbase has been previously initialized, so I won't
  85                support this.
  86
  87             idb->attrbase = GetOBase(OOPBase)->ob_CurrentAttrBase ++;
  88             */
  89
  90             base = 0;
  91         }
  92
  93         base = idb->attrbase;
  94         base <<= NUM_METHOD_BITS;
  95
  96         D(bug("Bucket found: id=%ld\n", base));
  97     }
  98     else
  99     {
 100         base = 0;
 101         D(bug("No existing bucket\n"));
 102
 103     }
 104
 105     if (base == 0)
 106     {
 107         /* Throw exception here */
 108     }
 109     ReleaseSemaphore(&GetOBase(OOPBase)->ob_IIDTableLock);
 110
 111     ReturnInt ("OOP_GetAttrBase", ULONG, base);
 112
 113     AROS_LIBFUNC_EXIT
 114
 115 } /* OOP_GetAttrBase  */
 116