Add a mutex to guarantee single writer to qemu_logfile handle.

[qemu.git] / util / range.c

diff --git a/util/range.c b/util/range.c
index e90c988dbf933f4f2c0593c77286f82ffed3ca16..098d9d2dc0b7bd791e9e6bc7d52aabaafe175c24 100644 (file)
--- a/util/range.c
+++ b/util/range.c
@@ -3,39 +3,36 @@
  *
  * Copyright (c) 2015-2016 Red Hat, Inc.
  *
- * This library is free software; you can redistribute it and/or
+ * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
- * This library is distributed in the hope that it will be useful,
+ * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU General Public
- * License along with this library; if not, see <http://www.gnu.org/licenses/>.
+ * General Public License for more details.
  *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <http://www.gnu.org/licenses/>.
  */
 
 #include "qemu/osdep.h"
 #include "qemu/range.h"
 
 /*
- * Operations on 64 bit address ranges.
- * Notes:
- *   - ranges must not wrap around 0, but can include the last byte ~0x0LL.
- *   - this can not represent a full 0 to ~0x0LL range.
+ * Return -1 if @a < @b, 1 @a > @b, and 0 if they touch or overlap.
+ * Both @a and @b must not be empty.
  */
-
-/* Return -1 if @a < @b, 1 if greater, and 0 if they touch or overlap. */
 static inline int range_compare(Range *a, Range *b)
 {
-    /* Zero a->end is 2**64, and therefore not less than any b->begin */
-    if (a->end && a->end < b->begin) {
+    assert(!range_is_empty(a) && !range_is_empty(b));
+
+    /* Careful, avoid wraparound */
+    if (b->lob && b->lob - 1 > a->upb) {
         return -1;
     }
-    if (b->end && a->begin > b->end) {
+    if (a->lob && a->lob - 1 > b->upb) {
         return 1;
     }
     return 0;
@@ -46,8 +43,7 @@ GList *range_list_insert(GList *list, Range *data)
 {
     GList *l;
 
-    /* Range lists require no empty ranges */
-    assert(data->begin < data->end || (data->begin && !data->end));
+    assert(!range_is_empty(data));
 
     /* Skip all list elements strictly less than data */
     for (l = list; l && range_compare(l->data, data) < 0; l = l->next) {