common: add destructor to intrusive_lru

values created during inserts that are
unreferenced are not deleted because evict()
does not delete values unless set.size() > lru_target_size.

For example, this condition is not met if the number
of entries in the intrusive_lru are less than or
equal to lru_target_size at the time of the
intrusive_lru's destruction.

Memory leaks due to the above scenario can be
reproduced if this commit is removed and
unittest_intrusive_lru is run under valgrind.

ex:

valgrind --tool=memcheck --leak-check=yes ./bin/unittest_intrusive_lru

Signed-off-by: Ali Maredia <amaredia@redhat.com>
(cherry picked from commit abd84ad770ffe10771aeae060514a42e76150569)

diff --git a/src/common/intrusive_lru.h b/src/common/intrusive_lru.h
index 422c24a14fb615eb8deda188b93eea97d717015a..2837f67984b3d8ac4f17aa927da22435330baa1f 100644 (file)
--- a/src/common/intrusive_lru.h
+++ b/src/common/intrusive_lru.h
@@ -166,6 +166,10 @@ public:
     evict();
   }
 
+  ~intrusive_lru() {
+    set_target_size(0);
+  }
+
   friend void intrusive_ptr_add_ref<>(intrusive_lru_base<Config> *);
   friend void intrusive_ptr_release<>(intrusive_lru_base<Config> *);
 };