docs: clarify vector element alignment description.
Change-Id: I6da153779010263e6fc4b51c64b01444aaadca17
Signed-off-by: Dave Wallace <dwallacelf@gmail.com>
diff --git a/docs/gettingstarted/developers/infrastructure.md b/docs/gettingstarted/developers/infrastructure.md
index 0361a63..b994607 100644
--- a/docs/gettingstarted/developers/infrastructure.md
+++ b/docs/gettingstarted/developers/infrastructure.md
@@ -48,13 +48,16 @@
Typically, the user header is not present. User headers allow for other
data structures to be built atop vppinfra vectors. Users may specify the
-alignment for data elements via the [vec]()\*\_aligned macros.
+alignment for first data element of a vector via the [vec]()\*\_aligned
+macros.
-Vectors elements can be any C type e.g. (int, double, struct bar). This
+Vector elements can be any C type e.g. (int, double, struct bar). This
is also true for data types built atop vectors (e.g. heap, pool, etc.).
-Many macros have \_a variants supporting alignment of vector data and
-\_h variants supporting non-zero-length vector headers. The \_ha
-variants support both.
+Many macros have \_a variants supporting alignment of vector elements
+and \_h variants supporting non-zero-length vector headers. The \_ha
+variants support both. Additionally cacheline alignment within a
+vector element structure can be specified using the
+[CLIB_CACHE_LINE_ALIGN_MARK]() macro.
Inconsistent usage of header and/or alignment related macro variants
will cause delayed, confusing failures.
diff --git a/src/vppinfra/vec.h b/src/vppinfra/vec.h
index 470a4f1..6f0e7e9 100644
--- a/src/vppinfra/vec.h
+++ b/src/vppinfra/vec.h
@@ -70,16 +70,18 @@
Typically, the header is not present. Headers allow for other
data structures to be built atop CLIB vectors.
- Users may specify the alignment for data elements via the
- vec_*_aligned macros.
+ Users may specify the alignment for first data element of a vector
+ via the vec_*_aligned macros.
- Vectors elements can be any C type e.g. (int, double, struct bar).
+ Vector elements can be any C type e.g. (int, double, struct bar).
This is also true for data types built atop vectors (e.g. heap,
pool, etc.).
- Many macros have _a variants supporting alignment of vector data
- and _h variants supporting non zero length vector headers.
- The _ha variants support both.
+ Many macros have \_a variants supporting alignment of vector elements
+ and \_h variants supporting non-zero-length vector headers. The \_ha
+ variants support both. Additionally cacheline alignment within a
+ vector element structure can be specified using the
+ CLIB_CACHE_LINE_ALIGN_MARK() macro.
Standard programming error: memorize a pointer to the ith element
of a vector then expand it. Vectors expand by 3/2, so such code