+static inline u8
+position_lt (svm_fifo_t * f, u32 a, u32 b)
+{
+ return (ooo_segment_distance_to_tail (f, a)
+ < ooo_segment_distance_to_tail (f, b));
+}
+
+static inline u8
+position_leq (svm_fifo_t * f, u32 a, u32 b)
+{
+ return (ooo_segment_distance_to_tail (f, a)
+ <= ooo_segment_distance_to_tail (f, b));
+}
+
+static inline u8
+position_gt (svm_fifo_t * f, u32 a, u32 b)
+{
+ return (ooo_segment_distance_to_tail (f, a)
+ > ooo_segment_distance_to_tail (f, b));
+}
+
+static inline u32
+position_diff (svm_fifo_t * f, u32 posa, u32 posb)
+{
+ return ooo_segment_distance_to_tail (f, posa)
+ - ooo_segment_distance_to_tail (f, posb);
+}
+
+static inline u32
+ooo_segment_end_pos (svm_fifo_t * f, ooo_segment_t * s)
+{
+ return (s->start + s->length) % f->nitems;
+}
+
+u8 *
+format_ooo_segment (u8 * s, va_list * args)
+{
+ ooo_segment_t *seg = va_arg (*args, ooo_segment_t *);
+
+ s = format (s, "pos %u, len %u, next %d, prev %d",
+ seg->start, seg->length, seg->next, seg->prev);
+ return s;
+}
+
+u8 *
+format_ooo_list (u8 * s, va_list * args)
+{
+ svm_fifo_t *f = va_arg (*args, svm_fifo_t *);
+ u32 ooo_segment_index = f->ooos_list_head;
+ ooo_segment_t *seg;
+
+ while (ooo_segment_index != OOO_SEGMENT_INVALID_INDEX)
+ {
+ seg = pool_elt_at_index (f->ooo_segments, ooo_segment_index);
+ s = format (s, " %U\n", format_ooo_segment, seg);
+ ooo_segment_index = seg->next;
+ }
+ return s;
+}
+
+u8 *
+format_svm_fifo (u8 * s, va_list * args)
+{
+ svm_fifo_t *f = va_arg (*args, svm_fifo_t *);
+ int verbose = va_arg (*args, int);
+
+ s = format (s, "cursize %u nitems %u has_event %d\n",
+ f->cursize, f->nitems, f->has_event);
+ s = format (s, " head %d tail %d\n", f->head, f->tail);
+
+ if (verbose > 1)
+ s = format
+ (s, " server session %d thread %d client session %d thread %d\n",
+ f->master_session_index, f->master_thread_index,
+ f->client_session_index, f->client_thread_index);
+
+ if (verbose)
+ {
+ s = format (s, " ooo pool %d active elts\n",
+ pool_elts (f->ooo_segments));
+ if (svm_fifo_has_ooo_data (f))
+ s = format (s, " %U", format_ooo_list, f);
+ }
+ return s;
+}
+