rom/intuition/freeclass.c

   1 /*
   2     Copyright © 1995-2013, The AROS Development Team. All rights reserved.
   3     Copyright © 2001-2003, The MorphOS Development Team. All Rights Reserved.
   4     $Id$
   5
   6     Free a BOOPSI Class.
   7 */
   8
   9 #include <proto/exec.h>
  10 #include "intuition_intern.h"
  11
  12 /*****************************************************************************
  13
  14     NAME */
  15 #include <intuition/classes.h>
  16 #include <proto/intuition.h>
  17
  18         AROS_LH1(BOOL, FreeClass,
  19
  20 /*  SYNOPSIS */
  21         AROS_LHA(struct IClass *, iclass, A0),
  22
  23 /*  LOCATION */
  24         struct IntuitionBase *, IntuitionBase, 119, Intuition)
  25
  26 /*  FUNCTION
  27         Only for class implementatores.
  28
  29         Tries to free a class which has been created with MakeClass() in the
  30         first place. This will not succeed in all cases: Classes which
  31         still have living objects or which are still being used by subclasses
  32         can't simply be freed. In this case this call will fail.
  33
  34         Public classes will always be removed with RemoveClass() no matter
  35         if FreeClass() would succeed or not. This gurantees that after the
  36         call to FreeClass() no new objects can be created.
  37
  38         If you have a pointer to allocated memory in cl_UserData, you must
  39         make a copy of that pointer, call FreeClass() and if the call
  40         succeeded, you may free the memory. If you don't follow these rules,
  41         you might end up with a class which is partially freed.
  42
  43     INPUTS
  44         iclass - The pointer you got from MakeClass().
  45
  46     RESULT
  47         FALSE if the class couldn't be freed at this time. This can happen
  48         either if there are still objects from this class or if the class
  49         is used a SuperClass of at least another class.
  50
  51         TRUE if the class could be freed. You must not use iclass after
  52         that.
  53
  54     NOTES
  55         *Always* calls RemoveClass().
  56
  57     EXAMPLE
  58         // Free a public class with dynamic memory in cl_UserD
  59
  60         int freeMyClass (Class * cl)
  61         {
  62             struct MyPerClassData * mpcd;
  63
  64             mpcd = (struct MyPerClassData *)cl->cl_UserData;
  65
  66             if (FreeClass (cl)
  67             {
  68                 FreeMem (mpcd, sizeof (struct MyPerClassData));
  69                 return (TRUE);
  70             }
  71
  72             return (FALSE);
  73         }
  74
  75     BUGS
  76
  77     SEE ALSO
  78         MakeClass(), "Basic Object-Oriented Programming System for Intuition"
  79         and "Boopsi Class Reference" Document.
  80
  81     INTERNALS
  82
  83 *****************************************************************************/
  84 {
  85     AROS_LIBFUNC_INIT
  86
  87     BOOL rv = FALSE;
  88
  89     SANITY_CHECKR(iclass,FALSE)
  90
  91     ObtainSemaphore(&GetPrivIBase(IntuitionBase)->ClassListLock);
  92
  93     /*
  94         Make sure no one creates another object from this class. For private
  95         classes, this call does nothing.
  96     */
  97     RemoveClass(iclass);
  98
  99     if (iclass->cl_SubclassCount == 0 && iclass->cl_ObjectCount == 0)
 100     {
 101         AROS_ATOMIC_DEC(iclass->cl_Super->cl_SubclassCount);
 102
 103         DeletePool(iclass->cl_MemoryPool);
 104         FreeMem(iclass, sizeof(Class));
 105
 106         rv = TRUE;
 107     }
 108
 109     ReleaseSemaphore(&GetPrivIBase(IntuitionBase)->ClassListLock);
 110
 111     return rv;
 112
 113     AROS_LIBFUNC_EXIT
 114 } /* FreeClass() */