diff mbox

[dpdk-dev,v1,08/15] eal: define macro container_of

Message ID 20160708190945.24225-9-viktorin@rehivetech.com (mailing list archive)
State Superseded, archived
Headers

Commit Message

Jan Viktorin July 8, 2016, 7:09 p.m. UTC 
  Signed-off-by: Jan Viktorin <viktorin@rehivetech.com>
---
 lib/librte_eal/common/include/rte_common.h | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)
diff mbox

Patch

diff --git a/lib/librte_eal/common/include/rte_common.h b/lib/librte_eal/common/include/rte_common.h
index 332f2a4..a9b6792 100644
--- a/lib/librte_eal/common/include/rte_common.h
+++ b/lib/librte_eal/common/include/rte_common.h
@@ -322,6 +322,22 @@  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);
+ */
+#define container_of(p, type, member) \
+	((type *) (((char *) (p)) - offsetof(type, member)))
+
 #define _RTE_STR(x) #x
 /** Take a macro value and get a string version of it */
 #define RTE_STR(x) _RTE_STR(x)