[dpdk-dev] [PATCH v9 01/25] eal: define macro container_of
Shreyansh Jain
shreyansh.jain at nxp.com
Wed Sep 7 16:07:53 CEST 2016
Signed-off-by: Jan Viktorin <viktorin at rehivetech.com>
Signed-off-by: Shreyansh Jain <shreyansh.jain at nxp.com>
---
lib/librte_eal/common/include/rte_common.h | 21 +++++++++++++++++++++
1 file changed, 21 insertions(+)
diff --git a/lib/librte_eal/common/include/rte_common.h b/lib/librte_eal/common/include/rte_common.h
index 332f2a4..c5d94f3 100644
--- a/lib/librte_eal/common/include/rte_common.h
+++ b/lib/librte_eal/common/include/rte_common.h
@@ -322,6 +322,27 @@ rte_bsf32(uint32_t v)
#define offsetof(TYPE, MEMBER) __builtin_offsetof (TYPE, MEMBER)
#endif
+/**
+ * Return pointer to the wrapping struct instance.
+ * Example:
+ *
+ * struct wrapper {
+ * ...
+ * struct child c;
+ * ...
+ * };
+ *
+ * struct child *x = obtain(...);
+ * struct wrapper *w = container_of(x, struct wrapper, c);
+ *
+ * Some implementation already have this defined, thus, conditional
+ * declaration.
+ */
+#ifndef container_of
+#define container_of(p, type, member) \
+ ((type *) (((char *) (p)) - offsetof(type, member)))
+#endif
+
#define _RTE_STR(x) #x
/** Take a macro value and get a string version of it */
#define RTE_STR(x) _RTE_STR(x)
--
2.7.4
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