From 0e2be09d6c4c78414104dd876dfd503203e90fc3 Mon Sep 17 00:00:00 2001
From: Pavel Charvat <pchar@ucw.cz>
Date: Sun, 17 Dec 2017 17:51:11 +0100
Subject: [PATCH] CLists, SLists: Extended interface for merging of link lists.

---
 ucw/clists.h   | 19 +++++++++++++++++++
 ucw/mainloop.c |  4 ++--
 ucw/slists.h   | 46 ++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 67 insertions(+), 2 deletions(-)

diff --git a/ucw/clists.h b/ucw/clists.h
index d327479f..809c480d 100644
--- a/ucw/clists.h
+++ b/ucw/clists.h
@@ -2,6 +2,7 @@
  *	UCW Library -- Circular Linked Lists
  *
  *	(c) 2003--2010 Martin Mares <mj@ucw.cz>
+ *	(c) 2017 Pavel Charvat <pchar@ucw.cz>
  *
  *	This software may be freely distributed and used according to the terms
  *	of the GNU Lesser General Public License.
@@ -189,6 +190,24 @@ static inline void clist_insert_list_after(clist *what, cnode *after)
     }
 }
 
+/**
+ * Merge two lists by inserting the list @what in front of all other nodes in a different list @l.
+ * The first list is then cleared.
+ **/
+static inline void clist_add_list_head(clist *l, clist *what)
+{
+  clist_insert_list_after(what, &l->head);
+}
+
+/**
+ * Merge two lists by inserting the list @what after all other nodes in a different list @l.
+ * The first list is then cleared.
+ **/
+static inline void clist_add_list_tail(clist *l, clist *what)
+{
+  clist_insert_list_after(what, l->head.prev);
+}
+
 /**
  * Move all items from a source list to a destination list. The source list
  * becomes empty, the original contents of the destination list are destroyed.
diff --git a/ucw/mainloop.c b/ucw/mainloop.c
index 920d0f0b..dcc0f749 100644
--- a/ucw/mainloop.c
+++ b/ucw/mainloop.c
@@ -183,9 +183,9 @@ main_destroy(struct main_context *m)
   main_prepare_delete(m);
 
   // Close all files
-  clist_insert_list_after(&m->file_active_list, m->file_list.head.prev);
+  clist_add_list_tail(&m->file_list, &m->file_active_list);
 #ifdef CONFIG_UCW_EPOLL
-  clist_insert_list_after(&m->file_recalc_list, m->file_list.head.prev);
+  clist_add_list_tail(&m->file_list, &m->file_recalc_list);
 #endif
   CLIST_FOR_EACH(struct main_file *, f, m->file_list)
     close(f->fd);
diff --git a/ucw/slists.h b/ucw/slists.h
index 1325c123..a9eb996e 100644
--- a/ucw/slists.h
+++ b/ucw/slists.h
@@ -2,6 +2,7 @@
  *	UCW Library -- Single-Linked Lists
  *
  *	(c) 2005 Martin Mares <mj@ucw.cz>
+ *	(c) 2017 Pavel Charvat <pchar@ucw.cz>
  *
  *	This software may be freely distributed and used according to the terms
  *	of the GNU Lesser General Public License.
@@ -173,6 +174,51 @@ static inline void slist_remove_tail(slist *l)
   slist_remove(l, l->last);
 }
 
+/**
+ * Merge two lists by inserting the list @what in front of all other nodes in a different list @l.
+ * The first list is then cleared.
+ **/
+static inline void slist_add_list_head(slist *l, slist *what)
+{
+  if (!slist_empty(what))
+    {
+      if (!slist_empty(l))
+	what->last->next = l->head.next;
+      else
+	l->last = what->last;
+      l->head.next = what->head.next;
+      slist_init(what);
+    }
+}
+
+/**
+ * Merge two lists by inserting the list @what after all other nodes in a different list @l.
+ * The first list is then cleared.
+ **/
+static inline void slist_add_list_tail(slist *l, slist *what)
+{
+  if (!slist_empty(what))
+    {
+      if (!slist_empty(l))
+	l->last->next = what->head.next;
+      else
+	l->head.next = what->head.next;
+      l->last = what->last;
+      slist_init(what);
+    }
+}
+
+/**
+ * Move all items from a source list to a destination list. The source list
+ * becomes empty, the original contents of the destination list are destroyed.
+ **/
+static inline void slist_move(slist *to, slist *from)
+{
+  to->head.next = from->head.next;
+  to->last = from->last;
+  slist_init(from);
+}
+
 /**
  * Compute the number of nodes in @l. Beware linear time complexity.
  **/
-- 
2.39.5