--- libelwix/src/ring.c	2026/02/10 15:49:08	1.4.4.1
+++ libelwix/src/ring.c	2026/02/10 18:23:53	1.5.2.1
@@ -3,7 +3,7 @@
 *  by Michael Pounov <misho@elwix.org>
 *
 * $Author: misho $
-* $Id: ring.c,v 1.4.4.1 2026/02/10 15:49:08 misho Exp $
+* $Id: ring.c,v 1.5.2.1 2026/02/10 18:23:53 misho Exp $
 *
 **************************************************************************
 The ELWIX and AITNET software is distributed under the following
@@ -284,6 +284,7 @@ lrb_purge(lrbuf_t *lrb)
 
 	atomic_store_explicit((atomic_int*) &lrb->lrb_head, 0, memory_order_relaxed);
 	atomic_store_explicit((atomic_int*) &lrb->lrb_tail, 0, memory_order_relaxed);
+	atomic_store_explicit((atomic_int*) &lrb->lrb_full, 0, memory_order_relaxed);
 }
 
 /*
@@ -298,8 +299,9 @@ lrb_isempty(lrbuf_t *lrb)
 	if (!lrb)
 		return -1;
 
-	return (atomic_load_explicit((atomic_int*) &lrb->lrb_head, memory_order_acquire) ==
-		atomic_load_explicit((atomic_int*) &lrb->lrb_tail, memory_order_acquire));
+	return (!atomic_load_explicit((atomic_int*) &lrb->lrb_full, memory_order_acquire) &&
+			(atomic_load_explicit((atomic_int*) &lrb->lrb_head, memory_order_acquire) ==
+			atomic_load_explicit((atomic_int*) &lrb->lrb_tail, memory_order_acquire)));
 }
 
 /*
@@ -318,11 +320,11 @@ lrb_isfull(lrbuf_t *lrb)
 	if (!lrb->lrb_size)
 		return 1;
 
-	t = atomic_load_explicit((atomic_int*) &lrb->lrb_tail, memory_order_acquire);
-	h = atomic_load_explicit((atomic_int*) &lrb->lrb_head, memory_order_relaxed) + 1;
-	if (h >= lrb->lrb_size)
-		h ^= h;
+	if (!atomic_load_explicit((atomic_int*) &lrb->lrb_full, memory_order_acquire))
+		return 0;
 
+	t = atomic_load_explicit((atomic_int*) &lrb->lrb_tail, memory_order_acquire);
+	h = atomic_load_explicit((atomic_int*) &lrb->lrb_head, memory_order_acquire);
 	return (h == t);
 }
 
@@ -338,7 +340,7 @@ lrb_isfull(lrbuf_t *lrb)
 int
 lrb_enqueue(lrbuf_t *lrb, void *data, size_t len, int lost)
 {
-	int h, t, n, t2, unused, drop = 0;
+	int h, t = 0, n, t2 = 0, unused, drop = 0;
 
 	if (!lrb || !lrb->lrb_data)
 		return -1;
@@ -370,7 +372,8 @@ lrb_enqueue(lrbuf_t *lrb, void *data, size_t len, int 
 		n = len - n;
 	}
 
-	atomic_store_explicit((atomic_int*) &lrb->lrb_head, n, memory_order_release);
+	h = n;
+	atomic_store_explicit((atomic_int*) &lrb->lrb_head, h, memory_order_release);
 	if (drop > 0)
 		while (42) {
 			n = t;
@@ -380,6 +383,9 @@ lrb_enqueue(lrbuf_t *lrb, void *data, size_t len, int 
 			t = n;
 			t2 = (t + drop) % lrb->lrb_size;
 		}
+	else
+		t2 = atomic_load_explicit((atomic_int*) &lrb->lrb_tail, memory_order_acquire);
+	atomic_store_explicit((atomic_int*) &lrb->lrb_full, (h == t2), memory_order_release);
 	return 0;
 }
 
@@ -394,7 +400,7 @@ lrb_enqueue(lrbuf_t *lrb, void *data, size_t len, int 
 int
 lrb_dequeue(lrbuf_t *lrb, void *data, size_t len)
 {
-	int h, t, t2, n, l;
+	int h, t, t2, n, l, f;
 
 	if (!lrb)
 		return -1;
@@ -406,12 +412,16 @@ lrb_dequeue(lrbuf_t *lrb, void *data, size_t len)
 	while (42) {
 		t = atomic_load_explicit((atomic_int*) &lrb->lrb_tail, memory_order_acquire);
 		h = atomic_load_explicit((atomic_int*) &lrb->lrb_head, memory_order_acquire);
+		f = atomic_load_explicit((atomic_int*) &lrb->lrb_full, memory_order_acquire);
 
 		l = h - t;
 		if (l < 0)
 			l += lrb->lrb_size;
-		if (!l)
-			return 0;
+		if (!l) {
+			if (!f)
+				return 0;
+			l = lrb->lrb_size;
+		}
 		if (l > len)
 			l = len;
 
@@ -430,8 +440,10 @@ lrb_dequeue(lrbuf_t *lrb, void *data, size_t len)
 
 		n = t;
 		if (atomic_compare_exchange_weak_explicit((atomic_int*) &lrb->lrb_tail,
-					&n, t2, memory_order_release, memory_order_relaxed))
+					&n, t2, memory_order_release, memory_order_relaxed)) {
+			atomic_store_explicit((atomic_int*) &lrb->lrb_full, 0, memory_order_release);
 			return l;
+		}
 	}
 
 	return 0;