From 226a9d9c34a2d187f978a25874488e5b07986d7c Mon Sep 17 00:00:00 2001
From: Justus Winter <4winter@informatik.uni-hamburg.de>
Date: Sun, 7 Jun 2015 00:58:36 +0200
Subject: libihash: prefer performance degradation over failure

* libihash/ihash.c (hurd_ihash_add): Add the item even though we are
above the load factor if resizing failed.
---
 libihash/ihash.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

(limited to 'libihash')

diff --git a/libihash/ihash.c b/libihash/ihash.c
index a97de3ee..87d7abf4 100644
--- a/libihash/ihash.c
+++ b/libihash/ihash.c
@@ -301,12 +301,14 @@ hurd_ihash_add (hurd_ihash_t ht, hurd_ihash_key_t key, hurd_ihash_value_t item)
 {
   struct hurd_ihash old_ht = *ht;
   int was_added;
+  int fatal = 0;	/* bail out on allocation errors */
   unsigned int i;
 
   if (ht->size)
     {
       /* Only fill the hash table up to its maximum load factor.  */
       if (hurd_ihash_get_load (ht) <= ht->max_load)
+      add_one:
 	if (add_one (ht, key, item))
 	  return 0;
     }
@@ -324,7 +326,15 @@ hurd_ihash_add (hurd_ihash_t ht, hurd_ihash_key_t key, hurd_ihash_value_t item)
   if (ht->items == NULL)
     {
       *ht = old_ht;
-      return ENOMEM;
+      if (fatal || ht->size == 0)
+        return ENOMEM;
+
+      /* We prefer performance degradation over failure.  Therefore,
+	 we add the item even though we are above the load factor.  If
+	 the table is full, this will fail.  We set the fatal flag to
+	 avoid looping.	 */
+      fatal = 1;
+      goto add_one;
     }
 
   /* We have to rehash the old entries.  */
-- 
cgit v1.2.3