logind: properly clean up user cgroups when they run empty

[elogind.git] / src / shared / macro.h

diff --git a/src/shared/macro.h b/src/shared/macro.h
index 19f259e4f1166c24a5acfde409cb51e17b00b284..1c0aa915ad3e86387ef8d949794eda090222b175 100644 (file)
--- a/src/shared/macro.h
+++ b/src/shared/macro.h
@@ -9,16 +9,16 @@
   Copyright 2010 Lennart Poettering
 
   systemd 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
+  under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 of the License, or
   (at your option) any later version.
 
   systemd 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.
+  Lesser General Public License for more details.
 
-  You should have received a copy of the GNU General Public License
+  You should have received a copy of the GNU Lesser General Public License
   along with systemd; If not, see <http://www.gnu.org/licenses/>.
 ***/
 
@@ -57,6 +57,17 @@ static inline size_t ALIGN_TO(size_t l, size_t ali) {
 
 #define ELEMENTSOF(x) (sizeof(x)/sizeof((x)[0]))
 
+/*
+ * container_of - cast a member of a structure out to the containing structure
+ * @ptr: the pointer to the member.
+ * @type: the type of the container struct this is embedded in.
+ * @member: the name of the member within the struct.
+ *
+ */
+#define container_of(ptr, type, member) ({ \
+        const typeof( ((type *)0)->member ) *__mptr = (ptr); \
+        (type *)( (char *)__mptr - offsetof(type,member) );})
+
 #ifndef MAX
 #define MAX(a,b)                                \
         __extension__ ({                        \