vcl/session: replicate events for shared sessions

Change-Id: I7fb5402d4a530b5f2ffd9bb5787632099f4b4189
Signed-off-by: Florin Coras <fcoras@cisco.com>

2 files changed, 43 insertions, 7 deletions

diff --git a/src/svm/svm_fifo.c b/src/svm/svm_fifo.c
index e7a1188d591..b53a2e294f7 100644
--- a/src/svm/svm_fifo.c
+++ b/src/svm/svm_fifo.c
@@ -845,6 +845,29 @@ svm_fifo_init_pointers (svm_fifo_t * f, u32 pointer)
   f->head = f->tail = pointer % f->nitems;
 }
 
+void
+svm_fifo_add_subscriber (svm_fifo_t * f, u8 subscriber)
+{
+  if (f->n_subscribers >= SVM_FIFO_MAX_EVT_SUBSCRIBERS)
+    return;
+  f->subscribers[f->n_subscribers++] = subscriber;
+}
+
+void
+svm_fifo_del_subscriber (svm_fifo_t * f, u8 subscriber)
+{
+  int i;
+
+  for (i = 0; i < f->n_subscribers; i++)
+    {
+      if (f->subscribers[i] != subscriber)
+	continue;
+      f->subscribers[i] = f->subscribers[f->n_subscribers - 1];
+      f->n_subscribers--;
+      break;
+    }
+}
+
 #endif
 /*
  * fd.io coding-style-patch-verification: ON
diff --git a/src/svm/svm_fifo.h b/src/svm/svm_fifo.h
index 613e0cad5eb..b0d38ed4f0a 100644
--- a/src/svm/svm_fifo.h
+++ b/src/svm/svm_fifo.h
@@ -40,6 +40,7 @@ format_function_t format_ooo_list;
 #define OOO_SEGMENT_INVALID_INDEX 	((u32)~0)
 #define SVM_FIFO_INVALID_SESSION_INDEX 	((u32)~0)
 #define SVM_FIFO_INVALID_INDEX		((u32)~0)
+#define SVM_FIFO_MAX_EVT_SUBSCRIBERS	8
 
 enum
 {
@@ -57,13 +58,13 @@ typedef struct
 
 typedef struct _svm_fifo
 {
+  CLIB_CACHE_LINE_ALIGN_MARK (shared_first);
   volatile u32 cursize;		/**< current fifo size */
   u32 nitems;
-    CLIB_CACHE_LINE_ALIGN_MARK (end_cursize);
 
+    CLIB_CACHE_LINE_ALIGN_MARK (shared_second);
   volatile u32 has_event;	/**< non-zero if deq event exists */
 
-  /* Backpointers */
   u32 master_session_index;
   u32 client_session_index;
   u8 master_thread_index;
@@ -71,13 +72,15 @@ typedef struct _svm_fifo
   u32 segment_manager;
   u32 segment_index;
   u32 ct_session_index;		/**< Local session index for vpp */
-    CLIB_CACHE_LINE_ALIGN_MARK (end_shared);
+  u32 freelist_index;		/**< aka log2(allocated_size) - const. */
+  i8 refcnt;			/**< reference count  */
+
+    CLIB_CACHE_LINE_ALIGN_MARK (consumer);
   u32 head;
   volatile u32 want_tx_ntf;	/**< producer wants nudge */
   volatile u32 has_tx_ntf;
-    CLIB_CACHE_LINE_ALIGN_MARK (end_consumer);
 
-  /* producer */
+    CLIB_CACHE_LINE_ALIGN_MARK (producer);
   u32 tail;
 
   ooo_segment_t *ooo_segments;	/**< Pool of ooo segments */
@@ -85,11 +88,13 @@ typedef struct _svm_fifo
   u32 ooos_newest;		/**< Last segment to have been updated */
   struct _svm_fifo *next;	/**< next in freelist/active chain */
   struct _svm_fifo *prev;	/**< prev in active chain */
+  u8 n_subscribers;
+  u8 subscribers[SVM_FIFO_MAX_EVT_SUBSCRIBERS];
+
 #if SVM_FIFO_TRACE
   svm_fifo_trace_elem_t *trace;
 #endif
-  u32 freelist_index;		/**< aka log2(allocated_size) - const. */
-  i8 refcnt;			/**< reference count  */
+
     CLIB_CACHE_LINE_ALIGN_MARK (data);
 } svm_fifo_t;
 
@@ -198,6 +203,8 @@ int svm_fifo_segments (svm_fifo_t * f, svm_fifo_segment_t * fs);
 void svm_fifo_segments_free (svm_fifo_t * f, svm_fifo_segment_t * fs);
 void svm_fifo_init_pointers (svm_fifo_t * f, u32 pointer);
 void svm_fifo_overwrite_head (svm_fifo_t * f, u8 * data, u32 len);
+void svm_fifo_add_subscriber (svm_fifo_t * f, u8 subscriber);
+void svm_fifo_del_subscriber (svm_fifo_t * f, u8 subscriber);
 format_function_t format_svm_fifo;
 
 /**
@@ -297,6 +304,12 @@ svm_fifo_needs_tx_ntf (svm_fifo_t * f, u32 n_last_deq)
   return 0;
 }
 
+always_inline u8
+svm_fifo_n_subscribers (svm_fifo_t * f)
+{
+  return f->n_subscribers;
+}
+
 u32 svm_fifo_number_ooo_segments (svm_fifo_t * f);
 ooo_segment_t *svm_fifo_first_ooo_segment (svm_fifo_t * f);