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Diffstat (limited to 'shared/nm-utils/nm-obj.h')
| -rw-r--r-- | shared/nm-utils/nm-obj.h | 82 |
1 files changed, 82 insertions, 0 deletions
diff --git a/shared/nm-utils/nm-obj.h b/shared/nm-utils/nm-obj.h new file mode 100644 index 00000000..1a9d4868 --- /dev/null +++ b/shared/nm-utils/nm-obj.h @@ -0,0 +1,82 @@ +/* -*- Mode: C; tab-width: 4; indent-tabs-mode: t; c-basic-offset: 4 -*- */ +/* NetworkManager -- Network link manager + * + * 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., 51 Franklin Street, Fifth Floor, + * Boston, MA 02110-1301 USA. + * + * (C) Copyright 2017 Red Hat, Inc. + */ + +#ifndef __NM_OBJ_H__ +#define __NM_OBJ_H__ + +/*****************************************************************************/ + +#define NM_OBJ_REF_COUNT_STACKINIT (G_MAXINT) + +typedef struct _NMObjBaseInst NMObjBaseInst; +typedef struct _NMObjBaseClass NMObjBaseClass; + +struct _NMObjBaseInst { + /* The first field of NMObjBaseInst is compatible with GObject. + * Basically, NMObjBaseInst is an abstract base type of GTypeInstance. + * + * If you do it right, you may derive a type of NMObjBaseInst as a proper GTypeInstance. + * That involves allocating a GType for it, which can be inconvenient because + * a GType is dynamically created (and the class can no longer be immutable + * memory). + * + * Even if your implementation of NMObjBaseInst is not a full fledged GType(Instance), + * you still can use GTypeInstances in the same context as you can decide based on the + * NMObjBaseClass with what kind of object you are dealing with. + * + * Basically, the only thing NMObjBaseInst gives you is access to an + * NMObjBaseClass instance. + */ + union { + const NMObjBaseClass *klass; + GTypeInstance g_type_instance; + }; +}; + +struct _NMObjBaseClass { + /* NMObjBaseClass is the base class of all NMObjBaseInst implementations. + * Note that it is also an abstract super class of GTypeInstance, that means + * you may implement a NMObjBaseClass as a subtype of GTypeClass. + * + * For that to work, you must properly set the GTypeClass instance (and it's + * GType). + * + * Note that to implement a NMObjBaseClass that is *not* a GTypeClass, you wouldn't + * set the GType. Hence, this field is only useful for type implementations that actually + * extend GTypeClass. + * + * In a way it is wrong that NMObjBaseClass has the GType member, because it is + * a base class of GTypeClass and doesn't necessarily use the GType. However, + * it is here so that G_TYPE_CHECK_INSTANCE_TYPE() and friends work correctly + * on any NMObjectClass. That means, while not necessary, it is convenient that + * a NMObjBaseClass has all members of GTypeClass. + * Also note that usually you have only one instance of a certain type, so this + * wastes just a few bytes for the unneeded GType. + */ + union { + GType g_type; + GTypeClass g_type_class; + }; +}; + +/*****************************************************************************/ + +#endif /* __NM_OBJ_H__ */ |