REORG: include: split common/xref.h into haproxy/xref{,-t}.h

The type is the only element needed by applet.h and hlua.h, while hlua.c
needs the various functions. XREF_BUSY was placed into the types as well
since it's better to have the special values there.
diff --git a/include/common/xref.h b/include/common/xref.h
deleted file mode 100644
index bdf292d..0000000
--- a/include/common/xref.h
+++ /dev/null
@@ -1,84 +0,0 @@
-#ifndef __XREF_H__
-#define __XREF_H__
-
-#include <haproxy/atomic.h>
-
-/* xref is used to create relation between two elements.
- * Once an element is released, it breaks the relation. If the
- * relation is already broken, it frees the xref struct.
- * The pointer between two elements is sort of a refcount with
- * max value 1. The relation is only between two elements.
- * The pointer and the type of elements a and b are conventional.
- */
-
-struct xref {
-	struct xref *peer;
-};
-
-#define XREF_BUSY ((struct xref *)1)
-
-static inline void xref_create(struct xref *xref_a, struct xref *xref_b)
-{
-	xref_a->peer = xref_b;
-	xref_b->peer = xref_a;
-}
-
-static inline struct xref *xref_get_peer_and_lock(struct xref *xref)
-{
-	struct xref *local;
-	struct xref *remote;
-
-	while (1) {
-
-		/* Get the local pointer to the peer. */
-		local = _HA_ATOMIC_XCHG(&xref->peer, XREF_BUSY);
-		__ha_barrier_atomic_store();
-
-		/* If the local pointer is NULL, the peer no longer exists. */
-		if (local == NULL) {
-			xref->peer = NULL;
-			return NULL;
-		}
-
-		/* If the local pointeru is BUSY, the peer try to acquire the
-		 * lock. We retry the process.
-		 */
-		if (local == XREF_BUSY)
-			continue;
-
-		/* We are locked, the peer can't disappear, try to acquire
-		 * the pper's lock. Note that remote can't be NULL.
-		 */
-		remote = _HA_ATOMIC_XCHG(&local->peer, XREF_BUSY);
-
-		/* The remote lock is BUSY, We retry the process. */
-		if (remote == XREF_BUSY) {
-			xref->peer = local;
-			__ha_barrier_store();
-			continue;
-		}
-
-		/* We have the lock, we return the value of the xref. */
-		return local;
-	}
-}
-
-static inline void xref_unlock(struct xref *xref, struct xref *peer)
-{
-	/* Release the peer. */
-	peer->peer = xref;
-
-	__ha_barrier_store();
-
-	/* Release myself. */
-	xref->peer = peer;
-}
-
-static inline void xref_disconnect(struct xref *xref, struct xref *peer)
-{
-	peer->peer = NULL;
-	__ha_barrier_store();
-	xref->peer = NULL;
-}
-
-#endif /* __XREF_H__ */
diff --git a/include/haproxy/xref-t.h b/include/haproxy/xref-t.h
new file mode 100644
index 0000000..a2aed54
--- /dev/null
+++ b/include/haproxy/xref-t.h
@@ -0,0 +1,45 @@
+/*
+ * include/haproxy/xref-t.h
+ * Atomic cross-references between two elements - types
+ *
+ * Copyright (C) 2017 Thierry Fournier <thierry.fournier@ozon.io>
+ * Copyright (C) 2020 Willy Tarreau - w@1wt.eu
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+ * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+ * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ */
+#ifndef __HAPROXY_XREF_T_H__
+#define __HAPROXY_XREF_T_H__
+
+/* xref is used to create relation between two elements.
+ * Once an element is released, it breaks the relation. If the
+ * relation is already broken, it frees the xref struct.
+ * The pointer between two elements is sort of a refcount with
+ * max value 1. The relation is only between two elements.
+ * The pointer and the type of elements a and b are conventional.
+ */
+
+#define XREF_BUSY ((struct xref *)1)
+
+struct xref {
+	struct xref *peer;
+};
+
+#endif /* __HAPROXY_XREF_T_H__ */
diff --git a/include/haproxy/xref.h b/include/haproxy/xref.h
new file mode 100644
index 0000000..e766385
--- /dev/null
+++ b/include/haproxy/xref.h
@@ -0,0 +1,106 @@
+/*
+ * include/haproxy/xref.h
+ * Atomic cross-references between two elements - functions
+ *
+ * Copyright (C) 2017 Thierry Fournier <thierry.fournier@ozon.io>
+ * Copyright (C) 2020 Willy Tarreau - w@1wt.eu
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+ * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+ * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ */
+#ifndef __HAPROXY_XREF_H__
+#define __HAPROXY_XREF_H__
+
+#include <haproxy/atomic.h>
+#include <haproxy/xref-t.h>
+
+/* xref is used to create relation between two elements.
+ * Once an element is released, it breaks the relation. If the
+ * relation is already broken, it frees the xref struct.
+ * The pointer between two elements is sort of a refcount with
+ * max value 1. The relation is only between two elements.
+ * The pointer and the type of elements a and b are conventional.
+ */
+
+static inline void xref_create(struct xref *xref_a, struct xref *xref_b)
+{
+	xref_a->peer = xref_b;
+	xref_b->peer = xref_a;
+}
+
+static inline struct xref *xref_get_peer_and_lock(struct xref *xref)
+{
+	struct xref *local;
+	struct xref *remote;
+
+	while (1) {
+
+		/* Get the local pointer to the peer. */
+		local = _HA_ATOMIC_XCHG(&xref->peer, XREF_BUSY);
+		__ha_barrier_atomic_store();
+
+		/* If the local pointer is NULL, the peer no longer exists. */
+		if (local == NULL) {
+			xref->peer = NULL;
+			return NULL;
+		}
+
+		/* If the local pointeru is BUSY, the peer try to acquire the
+		 * lock. We retry the process.
+		 */
+		if (local == XREF_BUSY)
+			continue;
+
+		/* We are locked, the peer can't disappear, try to acquire
+		 * the pper's lock. Note that remote can't be NULL.
+		 */
+		remote = _HA_ATOMIC_XCHG(&local->peer, XREF_BUSY);
+
+		/* The remote lock is BUSY, We retry the process. */
+		if (remote == XREF_BUSY) {
+			xref->peer = local;
+			__ha_barrier_store();
+			continue;
+		}
+
+		/* We have the lock, we return the value of the xref. */
+		return local;
+	}
+}
+
+static inline void xref_unlock(struct xref *xref, struct xref *peer)
+{
+	/* Release the peer. */
+	peer->peer = xref;
+
+	__ha_barrier_store();
+
+	/* Release myself. */
+	xref->peer = peer;
+}
+
+static inline void xref_disconnect(struct xref *xref, struct xref *peer)
+{
+	peer->peer = NULL;
+	__ha_barrier_store();
+	xref->peer = NULL;
+}
+
+#endif /* __HAPROXY_XREF_H__ */
diff --git a/include/types/applet.h b/include/types/applet.h
index 7b21f9a..d6b34a3 100644
--- a/include/types/applet.h
+++ b/include/types/applet.h
@@ -26,11 +26,11 @@
 #include <haproxy/buf.h>
 #include <haproxy/dynbuf-t.h>
 #include <haproxy/freq_ctr-t.h>
+#include <haproxy/xref-t.h>
 #include <types/hlua.h>
 #include <types/obj_type.h>
 #include <types/proxy.h>
 #include <types/stream.h>
-#include <common/xref.h>
 
 struct appctx;
 
diff --git a/include/types/hlua.h b/include/types/hlua.h
index 10a3303..990f9bc 100644
--- a/include/types/hlua.h
+++ b/include/types/hlua.h
@@ -7,7 +7,7 @@
 #include <lauxlib.h>
 
 #include <haproxy/regex-t.h>
-#include <common/xref.h>
+#include <haproxy/xref-t.h>
 
 #include <types/http_ana.h>
 #include <types/proxy.h>