mutter/common/cogl-handle.h

/*
 * Cogl
 *
 * An object oriented GL/GLES Abstraction/Utility Layer
 *
 * Copyright (C) 2008,2009 Intel Corporation.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */

#ifndef __COGL_HANDLE_H
#define __COGL_HANDLE_H

typedef struct _CoglHandleClass
{
  GQuark   type;
  void    *virt_free;
} CoglHandleClass;

/* All Cogl objects inherit from this base object by adding a member:
 *
 *   CoglHandleObject _parent;
 *
 * at the top of its main structure. This structure is initialized
 * when you call _cogl_#type_name#_handle_new (new_object);
 */
typedef struct _CoglHandleObject
{
  guint            ref_count;
  CoglHandleClass *klass;
} CoglHandleObject;

/* Helper macro to encapsulate the common code for COGL reference
   counted handles */

#ifdef COGL_HANDLE_DEBUG

#define _COGL_HANDLE_DEBUG_NEW(type_name, obj)			\
  g_debug ("COGL " G_STRINGIFY (type_name) " NEW   %p %i\n",    \
	  (obj), (obj)->ref_count)

#define _COGL_HANDLE_DEBUG_REF(type_name, handle)       G_STMT_START {  \
  CoglHandleObject *__obj = (CoglHandleObject *)handle;                 \
  g_debug ("COGL %s REF %p %i\n",	                                \
	   g_quark_to_string ((__obj)->klass->type),                    \
           (__obj), (__obj)->ref_count);                } G_STMT_END

#define _COGL_HANDLE_DEBUG_UNREF(type_name, handle)     G_STMT_START {  \
  CoglHandleObject *__obj = (CoglHandleObject *)handle;                 \
  g_debug ("COGL %s UNREF %p %i\n",	                                \
	   g_quark_to_string ((__obj)->klass->type),                    \
           (__obj), (__obj)->ref_count - 1);            } G_STMT_END

#define COGL_HANDLE_DEBUG_FREE(obj)     \
  g_debug ("COGL %s FREE %p\n", g_quark_to_string ((obj)->klass->type), (obj))

#else /* !COGL_HANDLE_DEBUG */

#define _COGL_HANDLE_DEBUG_NEW(type_name, obj)
#define _COGL_HANDLE_DEBUG_REF(type_name, obj)
#define _COGL_HANDLE_DEBUG_UNREF(type_name, obj)
#define COGL_HANDLE_DEBUG_FREE(obj)

#endif /* COGL_HANDLE_DEBUG */

#define COGL_HANDLE_DEFINE(TypeName, type_name)	                \
								\
static CoglHandleClass _cogl_##type_name##_class;               \
								\
static GQuark                                                   \
_cogl_##type_name##_get_type (void)                             \
{                                                               \
  static GQuark type = 0;                                       \
  if (!type)                                                    \
    type = g_quark_from_static_string ("Cogl"#TypeName);        \
  return type;                                                  \
}                                                               \
								\
static CoglHandle						\
_cogl_##type_name##_handle_new (Cogl##TypeName *new_obj)	\
{				                                \
  CoglHandleObject *obj = &new_obj->_parent;                    \
  obj->ref_count = 1;                                           \
								\
  obj->klass = &_cogl_##type_name##_class;                      \
  if (!obj->klass->type)                                        \
    {                                                           \
      obj->klass->type = _cogl_##type_name##_get_type ();       \
        obj->klass->virt_free = _cogl_##type_name##_free;       \
      }                                                         \
								\
    _COGL_HANDLE_DEBUG_NEW (TypeName, obj);                     \
    return (CoglHandle) new_obj;			        \
  }								\
								\
Cogl##TypeName *						\
_cogl_##type_name##_pointer_from_handle (CoglHandle handle)	\
{								\
  return (Cogl##TypeName *) handle;				\
}								\
								\
gboolean							\
cogl_is_##type_name (CoglHandle handle)			        \
{                                                               \
  CoglHandleObject *obj = (CoglHandleObject *)handle;           \
                                                                \
  if (handle == COGL_INVALID_HANDLE)                            \
    return FALSE;                                               \
                                                                \
  return (obj->klass->type == _cogl_##type_name##_get_type ()); \
}								\
								\
CoglHandle G_GNUC_DEPRECATED					\
cogl_##type_name##_ref (CoglHandle handle)			\
{								\
  if (!cogl_is_##type_name (handle))				\
    return COGL_INVALID_HANDLE;				        \
                                                                \
  _COGL_HANDLE_DEBUG_REF (TypeName, handle);			\
								\
  cogl_handle_ref (handle);                                     \
								\
  return handle;						\
}								\
								\
void G_GNUC_DEPRECATED					        \
cogl_##type_name##_unref (CoglHandle handle)			\
{								\
  if (!cogl_is_##type_name (handle))				\
    {                                                           \
      g_warning (G_STRINGIFY (cogl_##type_name##_unref)         \
                 ": Ignoring unref of Cogl handle "             \
                 "due to type mismatch");                       \
      return;							\
    }                                                           \
								\
  _COGL_HANDLE_DEBUG_UNREF (TypeName, handle);		        \
                                                                \
  cogl_handle_unref (handle);                                   \
}

#endif /* __COGL_HANDLE_H */