Sunc with trunk revision 58971.

[reactos.git] / lib / drivers / lwip / src / core / memp.c

diff --git a/lib/drivers/lwip/src/core/memp.c b/lib/drivers/lwip/src/core/memp.c
index 4da879a..9f680e2 100644 (file)
--- a/lib/drivers/lwip/src/core/memp.c
+++ b/lib/drivers/lwip/src/core/memp.c
@@ -176,19 +176,20 @@ static u8_t memp_memory[MEM_ALIGNMENT - 1
 
 #if MEMP_SANITY_CHECK
 /**
- * Check that memp-lists don't form a circle
+ * Check that memp-lists don't form a circle, using "Floyd's cycle-finding algorithm".
  */
 static int
 memp_sanity(void)
 {
-  s16_t i, c;
-  struct memp *m, *n;
+  s16_t i;
+  struct memp *t, *h;
 
   for (i = 0; i < MEMP_MAX; i++) {
-    for (m = memp_tab[i]; m != NULL; m = m->next) {
-      c = 1;
-      for (n = memp_tab[i]; n != NULL; n = n->next) {
-        if (n == m && --c < 0) {
+    t = memp_tab[i];
+    if(t != NULL) {
+      for (h = t->next; (t != NULL) && (h != NULL); t = t->next,
+        h = (((h->next != NULL) && (h->next->next != NULL)) ? h->next->next : NULL)) {
+        if (t == h) {
           return 0;
         }
       }