tailq: use a single cast macro

[dpdk.git] / lib / librte_eal / common / include / rte_tailq.h

diff --git a/lib/librte_eal/common/include/rte_tailq.h b/lib/librte_eal/common/include/rte_tailq.h
index d084d9a..6ac4b9b 100644 (file)
--- a/lib/librte_eal/common/include/rte_tailq.h
+++ b/lib/librte_eal/common/include/rte_tailq.h
@@ -48,11 +48,12 @@ extern "C" {
 #include <stdio.h>
 
 /** dummy structure type used by the rte_tailq APIs */
-struct rte_dummy {
-       TAILQ_ENTRY(rte_dummy) next; /**< Pointer entries for a tailq list */
+struct rte_tailq_entry {
+       TAILQ_ENTRY(rte_tailq_entry) next; /**< Pointer entries for a tailq list */
+       void *data; /**< Pointer to the data referenced by this tailq entry */
 };
 /** dummy */
-TAILQ_HEAD(rte_dummy_head, rte_dummy);
+TAILQ_HEAD(rte_tailq_entry_head, rte_tailq_entry);
 
 #define RTE_TAILQ_NAMESIZE 32
 
@@ -65,9 +66,15 @@ TAILQ_HEAD(rte_dummy_head, rte_dummy);
  * a multi-process app to find already-created elements in shared memory.
  */
 struct rte_tailq_head {
-       struct rte_dummy_head tailq_head; /**< NOTE: must be first element */
+       struct rte_tailq_entry_head tailq_head; /**< NOTE: must be first element */
 };
 
+/**
+ * Return the first tailq entry casted to the right struct.
+ */
+#define RTE_TAILQ_CAST(tailq_entry, struct_name) \
+       (struct struct_name *)&(tailq_entry)->tailq_head
+
 /**
  * Utility macro to make reserving a tailqueue for a particular struct easier.
  *
@@ -85,7 +92,7 @@ struct rte_tailq_head {
  *   element in the rte_tailq_head structure.
  */
 #define RTE_TAILQ_RESERVE(name, struct_name) \
-       (struct struct_name *)(&rte_eal_tailq_reserve(name)->tailq_head)
+       RTE_TAILQ_CAST(rte_eal_tailq_reserve(name), struct_name)
 
 /**
  * Utility macro to make reserving a tailqueue for a particular struct easier.
@@ -105,7 +112,7 @@ struct rte_tailq_head {
  *   element in the rte_tailq_head structure.
  */
 #define RTE_TAILQ_RESERVE_BY_IDX(idx, struct_name) \
-       (struct struct_name *)(&rte_eal_tailq_reserve_by_idx(idx)->tailq_head)
+       RTE_TAILQ_CAST(rte_eal_tailq_reserve_by_idx(idx), struct_name)
 
 /**
  * Utility macro to make looking up a tailqueue for a particular struct easier.
@@ -124,7 +131,7 @@ struct rte_tailq_head {
  *   element in the rte_tailq_head structure.
  */
 #define RTE_TAILQ_LOOKUP(name, struct_name) \
-       (struct struct_name *)(&rte_eal_tailq_lookup(name)->tailq_head)
+       RTE_TAILQ_CAST(rte_eal_tailq_lookup(name), struct_name)
 
 /**
  * Utility macro to make looking up a tailqueue for a particular struct easier.
@@ -143,7 +150,7 @@ struct rte_tailq_head {
  *   element in the rte_tailq_head structure.
  */
 #define RTE_TAILQ_LOOKUP_BY_IDX(idx, struct_name) \
-       (struct struct_name *)(&rte_eal_tailq_lookup_by_idx(idx)->tailq_head)
+       RTE_TAILQ_CAST(rte_eal_tailq_lookup_by_idx(idx), struct_name)
 
 /**
  * Reserve a slot in the tailq list for a particular tailq header