lib, zebra: Add a bit of code to look at fifo

When in a dev build add a bit of code to track max
depth of a fifo and to allow zebra to report on it.

Signed-off-by: Donald Sharp <sharpd@cumulusnetworks.com>

lib/stream.c

@@ -1109,6 +1109,10 @@ struct stream_fifo *stream_fifo_new(void)
 /* Add new stream to fifo. */
 void stream_fifo_push(struct stream_fifo *fifo, struct stream *s)
 {
+#if defined DEV_BUILD
+	size_t max, curmax;
+#endif
+
 	if (fifo->tail)
 		fifo->tail->next = s;
 	else
@@ -1116,8 +1120,15 @@ void stream_fifo_push(struct stream_fifo *fifo, struct stream *s)
 
 	fifo->tail = s;
 	fifo->tail->next = NULL;
-
+#if !defined DEV_BUILD
 	atomic_fetch_add_explicit(&fifo->count, 1, memory_order_release);
+#else
+	max = atomic_fetch_add_explicit(&fifo->count, 1, memory_order_release);
+	curmax = atomic_load_explicit(&fifo->max_count, memory_order_relaxed);
+	if (max > curmax)
+		atomic_store_explicit(&fifo->max_count, max,
+				      memory_order_relaxed);
+#endif
 }
 
 void stream_fifo_push_safe(struct stream_fifo *fifo, struct stream *s)

lib/stream.h

@@ -115,6 +115,9 @@ struct stream_fifo {
 
 	/* number of streams in this fifo */
 	_Atomic size_t count;
+#if defined DEV_BUILD
+	_Atomic size_t max_count;
+#endif
 
 	struct stream *head;
 	struct stream *tail;

zebra/zserv.c

@@ -939,6 +939,11 @@ static void zebra_show_client_detail(struct vty *vty, struct zserv *client)
 	vty_out(vty, "MAC-IP add notifications: %d\n", client->macipadd_cnt);
 	vty_out(vty, "MAC-IP delete notifications: %d\n", client->macipdel_cnt);
 
+#if defined DEV_BUILD
+	vty_out(vty, "Input Fifo: %zu:%zu Output Fifo: %zu:%zu\n",
+		client->ibuf_fifo->count, client->ibuf_fifo->max_count,
+		client->obuf_fifo->count, client->obuf_fifo->max_count);
+#endif
 	vty_out(vty, "\n");
 	return;
 }