ring: add RING_FOREACH_REVERSED_SAFEbitmap-crop.mem-control

1 files changed, 6 insertions, 0 deletions

diff --git a/common/ring.h b/common/ring.h
index 7fba50e..2d98ed8 100644
--- a/common/ring.h
+++ b/common/ring.h
@@ -151,6 +151,12 @@ static inline RingItem *ring_prev(Ring *ring, RingItem *pos)
             (var) = ring_prev(ring, var))
 
 
+#define RING_FOREACH_REVERSED_SAFE(var, next, ring)            \
+    for ((var) = ring_get_tail(ring);                          \
+            (var) && ((next) = ring_prev(ring, (var)), 1);     \
+            (var) = (next))
+
+
 static inline unsigned int ring_get_length(Ring *ring)
 {
     RingItem *i;