stats: add version field to stat segment base header

Add a version in the base header of the stat segment
To make support for multiple reader implementations safer.

Change-Id: I6816e2a51a98c2df1e621e80d4ef0b4ba4e9f47b
Type: feature
Signed-off-by: Ole Troan <ot@cisco.com>

2 files changed, 7 insertions, 0 deletions

diff --git a/src/vpp/stats/stat_segment.c b/src/vpp/stats/stat_segment.c
index 61b21babbe3..cef792fc622 100644
--- a/src/vpp/stats/stat_segment.c
+++ b/src/vpp/stats/stat_segment.c
@@ -272,6 +272,9 @@ vlib_map_stat_segment_init (void)
 
   sm->directory_vector_by_name = hash_create_string (0, sizeof (uword));
   sm->shared_header = shared_header = memaddr;
+
+  shared_header->version = STAT_SEGMENT_VERSION;
+
   sm->stat_segment_lockp = clib_mem_alloc (sizeof (clib_spinlock_t));
   clib_spinlock_init (sm->stat_segment_lockp);
 
diff --git a/src/vpp/stats/stat_segment.h b/src/vpp/stats/stat_segment.h
index b9ffedf2169..113eb9a25ad 100644
--- a/src/vpp/stats/stat_segment.h
+++ b/src/vpp/stats/stat_segment.h
@@ -70,11 +70,15 @@ typedef struct
 /* Default stat segment 32m */
 #define STAT_SEGMENT_DEFAULT_SIZE	(32<<20)
 
+/* Shared segment memory layout version */
+#define STAT_SEGMENT_VERSION		1
+
 /*
  * Shared header first in the shared memory segment.
  */
 typedef struct
 {
+  u64 version;
   atomic_int_fast64_t epoch;
   atomic_int_fast64_t in_progress;
   atomic_int_fast64_t directory_offset;