list: New function list_move().

An upcoming commit will add more users.

Signed-off-by: Ben Pfaff <blp@nicira.com>
Reviewed-by: Simon Horman <horms@verge.net.au>

diff --git a/lib/list.c b/lib/list.c
index 227546e..e341d45 100644 (file)
--- a/lib/list.c
+++ b/lib/list.c
@@ -101,6 +101,20 @@ list_moved(struct list *list)
     list->prev->next = list->next->prev = list;
 }
 
+/* Initializes 'dst' with the contents of 'src', compensating for moving it
+ * around in memory.  The effect is that, if 'src' was the head of a list, now
+ * 'dst' is the head of a list containing the same elements. */
+void
+list_move(struct list *dst, struct list *src)
+{
+    if (!list_is_empty(src)) {
+        *dst = *src;
+        list_moved(dst);
+    } else {
+        list_init(dst);
+    }
+}
+
 /* Removes 'elem' from its list and returns the element that followed it.
    Undefined behavior if 'elem' is not in a list. */
 struct list *

diff --git a/lib/list.h b/lib/list.h
index 786b176..0da082e 100644 (file)
--- a/lib/list.h
+++ b/lib/list.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2008, 2009, 2010, 2011 Nicira, Inc.
+ * Copyright (c) 2008, 2009, 2010, 2011, 2013 Nicira, Inc.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -40,6 +40,7 @@ void list_push_front(struct list *, struct list *);
 void list_push_back(struct list *, struct list *);
 void list_replace(struct list *, const struct list *);
 void list_moved(struct list *);
+void list_move(struct list *dst, struct list *src);
 
 /* List removal. */
 struct list *list_remove(struct list *);

diff --git a/ofproto/ofproto-dpif.c b/ofproto/ofproto-dpif.c
index 03d5c1f..7bfdad9 100644 (file)
--- a/ofproto/ofproto-dpif.c
+++ b/ofproto/ofproto-dpif.c
@@ -1533,14 +1533,9 @@ run_fast(struct ofproto *ofproto_)
     }
 
     ovs_mutex_lock(&ofproto->flow_mod_mutex);
-    if (ofproto->n_flow_mods) {
-        flow_mods = ofproto->flow_mods;
-        list_moved(&flow_mods);
-        list_init(&ofproto->flow_mods);
-        ofproto->n_flow_mods = 0;
-    } else {
-        list_init(&flow_mods);
-    }
+    list_move(&flow_mods, &ofproto->flow_mods);
+    list_init(&ofproto->flow_mods);
+    ofproto->n_flow_mods = 0;
     ovs_mutex_unlock(&ofproto->flow_mod_mutex);
 
     LIST_FOR_EACH_SAFE (fm, next_fm, list_node, &flow_mods) {
@@ -1556,14 +1551,9 @@ run_fast(struct ofproto *ofproto_)
     }
 
     ovs_mutex_lock(&ofproto->pin_mutex);
-    if (ofproto->n_pins) {
-        pins = ofproto->pins;
-        list_moved(&pins);
-        list_init(&ofproto->pins);
-        ofproto->n_pins = 0;
-    } else {
-        list_init(&pins);
-    }
+    list_move(&pins, &ofproto->pins);
+    list_init(&ofproto->pins);
+    ofproto->n_pins = 0;
     ovs_mutex_unlock(&ofproto->pin_mutex);
 
     LIST_FOR_EACH_SAFE (pin, next_pin, list_node, &pins) {