In some cases, the node context data is used to store two pointers
because the data is larger than the reserved 16 bytes. Having to define
intermediate structures just to be able to cast is tedious. Add two
pointers that take the same space than ctx.
Signed-off-by: Robin Jarry <rja...@redhat.com>
---
Notes:
v2:
* Added __extension__ (not sure where it is needed, I don't have access to
windows).
* It still fails the header check for C++. It seems not possible to align
an unnamed union...
Tyler, do you have an idea about how to fix that?
* Added static_assert to ensure the anonymous union is not larger than
RTE_NODE_CTX_SZ.
lib/graph/rte_graph_worker_common.h | 12 +++++++++++-
1 file changed, 11 insertions(+), 1 deletion(-)
diff --git a/lib/graph/rte_graph_worker_common.h
b/lib/graph/rte_graph_worker_common.h
index 36d864e2c14e..a60c2bc3f0c3 100644
--- a/lib/graph/rte_graph_worker_common.h
+++ b/lib/graph/rte_graph_worker_common.h
@@ -112,7 +112,14 @@ struct __rte_cache_aligned rte_node {
};
/* Fast path area */
#define RTE_NODE_CTX_SZ 16
- alignas(RTE_CACHE_LINE_SIZE) uint8_t ctx[RTE_NODE_CTX_SZ]; /**< Node
Context. */
+ __extension__ alignas(RTE_CACHE_LINE_SIZE) union {
+ uint8_t ctx[RTE_NODE_CTX_SZ];
+ /* Convenience aliases to store pointers without complex
casting. */
+ __extension__ struct {
+ void *ctx_ptr;
+ void *ctx_ptr2;
+ };
+ }; /**< Node Context. */
uint16_t size; /**< Total number of objects available. */
uint16_t idx; /**< Number of objects used. */
rte_graph_off_t off; /**< Offset of node in the graph reel. */
@@ -130,6 +137,9 @@ struct __rte_cache_aligned rte_node {
alignas(RTE_CACHE_LINE_MIN_SIZE) struct rte_node *nodes[]; /**< Next
nodes. */
};
+static_assert(offsetof(struct rte_node, size) - offsetof(struct rte_node, ctx)
== RTE_NODE_CTX_SZ,
+ "The node context anonymous union cannot be larger than
RTE_NODE_CTX_SZ");
+
/**
* @internal
*
--
2.44.0
