[Mesa-dev] [PATCH 1/4] util/tests: Expand collision test for hash table

[Thomas Helland]

Add a test to exercise a worst case collision scenario
that may cause us to not be able to find an empty
slot in the table even though it is not full.

V2: Feedback from Emil Velikov
    -Don't include code in the assert
---
 src/util/tests/hash_table/collision.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/src/util/tests/hash_table/collision.c b/src/util/tests/hash_table/collision.c
index 69a4c29eca..51a537757b 100644
--- a/src/util/tests/hash_table/collision.c
+++ b/src/util/tests/hash_table/collision.c
@@ -91,5 +91,19 @@ main(int argc, char **argv)
 
    _mesa_hash_table_destroy(ht, NULL);
 
+   /* Try inserting multiple items with the same hash
+    * This exercises a worst case scenario where we might fail to find
+    * an empty slot in the table, even though there is free space
+    */
+   ht = _mesa_hash_table_create(NULL, NULL, _mesa_key_string_equal);
+   for (i = 0; i < 100; i++) {
+      char *key = malloc(10);
+      sprintf(key, "spam%d", i);
+      entry2 = _mesa_hash_table_insert_pre_hashed(ht, bad_hash, key, NULL);
+      assert(entry2 != NULL);
+   }
+
+   _mesa_hash_table_destroy(ht, NULL);
+
    return 0;
 }
-- 
2.11.1