refcount: add reference couting utilility macros

Co-authored-by: Clemens Famulla-Conrad <cfamullaconrad@suse.de>
openSUSE · Jun 2, 2022 · 36febb3 · 36febb3
1 parent 68a77fb
commit 36febb3
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diff --git a/include/Makefile.am b/include/Makefile.am
@@ -32,6 +32,7 @@ wicked_include_HEADERS		= \
 	wicked/ovs.h		\
 	wicked/pci.h		\
 	wicked/ppp.h		\
+	wicked/refcount.h	\
 	wicked/resolver.h	\
 	wicked/route.h		\
 	wicked/secret.h		\

diff --git a/include/wicked/refcount.h b/include/wicked/refcount.h
@@ -0,0 +1,150 @@
+/*
+ *	refcount -- reference couting utils
+ *
+ *	Copyright (C) 2022 SUSE LLC
+ *
+ *	This program is free software; you can redistribute it and/or modify
+ *	it under the terms of the GNU General Public License as published by
+ *	the Free Software Foundation; either version 2 of the License, or
+ *	(at your option) any later version.
+ *
+ *	This program 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 General Public License for more details.
+ *
+ *	You should have received a copy of the GNU General Public License
+ *	along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ *	Authors:
+ *		Marius Tomaschewski
+ *		Clemens Famulla-Conrad
+ */
+#ifndef WICKED_REFCOUNT_H
+#define WICKED_REFCOUNT_H
+
+#include <wicked/types.h>
+
+typedef unsigned int	ni_refcount_t;
+
+extern ni_bool_t	ni_refcount_init(ni_refcount_t *refcount);
+extern ni_bool_t	ni_refcount_increment(ni_refcount_t *refcount);
+extern ni_bool_t	ni_refcount_decrement(ni_refcount_t *refcount);
+
+
+#define 		ni_refcounted_declare_new(prefix,args...)	\
+	prefix##_t *		prefix##_new(args)
+
+#define			ni_refcounted_declare_ref(prefix)		\
+	prefix##_t *		prefix##_ref(prefix##_t *)
+
+#define			ni_refcounted_declare_free(prefix)		\
+	void			prefix##_free(prefix##_t *)
+
+#define			ni_refcounted_declare_hold(prefix)		\
+	ni_bool_t		prefix##_hold(prefix##_t **, prefix##_t *)
+
+#define			ni_refcounted_declare_drop(prefix)		\
+	ni_bool_t		prefix##_drop(prefix##_t **)
+
+#define			ni_refcounted_declare_move(prefix)		\
+	ni_bool_t		prefix##_move(prefix##_t **, prefix##_t **)
+
+
+#define			ni_refcounted_define_new_xargs(prefix,		\
+					func_args, init_args)		\
+	prefix##_t *							\
+	prefix##_new func_args						\
+	{								\
+		prefix##_t *obj = malloc(sizeof(*obj));			\
+		if (obj) {						\
+			if (!prefix##_init init_args) {			\
+				free(obj);				\
+				return NULL;				\
+			}						\
+			if (!ni_refcount_init(&obj->refcount)) {	\
+				prefix##_destroy(obj);			\
+				free(obj);				\
+				return NULL;				\
+			}						\
+		}							\
+		return obj;						\
+	}
+#define			ni_refcounted_define_new0(prefix)		\
+			ni_refcounted_define_new_xargs(prefix,		\
+					(void), (obj))
+#define			ni_refcounted_define_new1(prefix, _1)		\
+			ni_refcounted_define_new_xargs(prefix,		\
+					(_1 a), (obj, a))
+#define			ni_refcounted_define_new2(prefix, _1, _2)	\
+			ni_refcounted_define_new_xargs(prefix,		\
+					(_1 a, _2 b), (obj, a, b))
+#define			ni_refcounted_define_new3(prefix, _1, _2, _3)	\
+			ni_refcounted_define_new_xargs(prefix,		\
+					(_1 a, _2 b, _3 c), (obj, a, b, c))
+#define			ni_refcounted_macro(_1, _2, _3, _4, NAME, ...) NAME
+
+#define			ni_refcounted_define_new(args...)		\
+			ni_refcounted_macro(args,			\
+				ni_refcounted_define_new3,		\
+				ni_refcounted_define_new2,		\
+				ni_refcounted_define_new1,		\
+				ni_refcounted_define_new0)(args)
+
+#define			ni_refcounted_define_ref(prefix)		\
+	prefix##_t *							\
+	prefix##_ref(prefix##_t *ref)					\
+	{								\
+		if (ref && ni_refcount_increment(&ref->refcount))	\
+			return ref;					\
+		return NULL;						\
+	}
+
+#define 		ni_refcounted_define_free(prefix)		\
+	void								\
+	prefix##_free(prefix##_t *ref)					\
+	{								\
+		if (ref && ni_refcount_decrement(&ref->refcount)) {	\
+			prefix##_destroy(ref);				\
+			free(ref);					\
+		}							\
+	}
+
+#define 		ni_refcounted_define_hold(prefix)		\
+	ni_bool_t							\
+	prefix##_hold(prefix##_t **tie, prefix##_t *ref)		\
+	{								\
+		prefix##_t *old;					\
+		if (tie && ref) {					\
+			old = *tie;					\
+			*tie = prefix##_ref(ref);			\
+			prefix##_free(old);				\
+			return TRUE;					\
+		}							\
+		return FALSE;						\
+	}
+
+#define 		ni_refcounted_define_drop(prefix)		\
+	ni_bool_t							\
+	prefix##_drop(prefix##_t **tie)					\
+	{								\
+		prefix##_t *old;					\
+		if (tie) {						\
+			old = *tie;					\
+			*tie = NULL;					\
+			prefix##_free(old);				\
+			return TRUE;					\
+		}							\
+		return FALSE;						\
+	}
+
+#define 		ni_refcounted_define_move(prefix)		\
+	ni_bool_t							\
+	prefix##_move(prefix##_t **dst, prefix##_t **src)		\
+	{								\
+		if (src && prefix##_hold(dst, *src))			\
+			return prefix##_drop(src);			\
+		return FALSE;						\
+	}
+
+#endif /* WICKED_REFCOUNT_H */
diff --git a/src/Makefile.am b/src/Makefile.am
@@ -93,6 +93,7 @@ libwicked_la_SOURCES		= \
 	ppp.c			\
 	pppd.c			\
 	process.c		\
+	refcount.c		\
 	resolver.c		\
 	rfkill.c		\
 	route.c			\

diff --git a/src/refcount.c b/src/refcount.c
@@ -0,0 +1,54 @@
+/*
+ *	refcount -- reference couting utils
+ *
+ *	Copyright (C) 2022 SUSE LLC
+ *
+ *	This program is free software; you can redistribute it and/or modify
+ *	it under the terms of the GNU General Public License as published by
+ *	the Free Software Foundation; either version 2 of the License, or
+ *	(at your option) any later version.
+ *
+ *	This program 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 General Public License for more details.
+ *
+ *	You should have received a copy of the GNU General Public License
+ *	along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ *	Authors:
+ *		Marius Tomaschewski
+ *		Clemens Famulla-Conrad
+ */
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <wicked/types.h>
+#include <wicked/refcount.h>
+#include <wicked/logging.h>
+
+ni_bool_t
+ni_refcount_init(ni_refcount_t *refcount)
+{
+	ni_assert(refcount);
+	*refcount = 1;
+	return TRUE;
+}
+
+ni_bool_t
+ni_refcount_increment(ni_refcount_t *refcount)
+{
+	ni_assert(refcount && *refcount);
+	*refcount += 1;
+	return *refcount != 0;
+}
+
+ni_bool_t
+ni_refcount_decrement(ni_refcount_t *refcount)
+{
+	ni_assert(refcount && *refcount);
+	*refcount -= 1;
+	return *refcount == 0;
+}
+