1 files changed, 25 insertions, 1 deletions
diff --git a/tests/cache/test_dbm_backend.py b/tests/cache/test_dbm_backend.py
index 37ec588..138a0af 100644
--- a/tests/cache/test_dbm_backend.py
+++ b/tests/cache/test_dbm_backend.py
@@ -1,5 +1,5 @@
 from ._fixtures import _GenericBackendTest, _GenericMutexTest
-from . import eq_
+from . import eq_, assert_raises_message
 from unittest import TestCase
 from threading import Thread
 import time
@@ -41,6 +41,30 @@ class DBMMutexTest(_GenericMutexTest):
         }
     }
 
+    def test_release_assertion_thread(self):
+        backend = self._backend()
+        m1 = backend.get_mutex("foo")
+        assert_raises_message(
+            AssertionError,
+            "this thread didn't do the acquire",
+            m1.release
+        )
+
+    def test_release_assertion_key(self):
+        backend = self._backend()
+        m1 = backend.get_mutex("foo")
+        m2 = backend.get_mutex("bar")
+
+        m1.acquire()
+        try:
+            assert_raises_message(
+                AssertionError,
+                "No acquire held for key 'bar'",
+                m2.release
+            )
+        finally:
+            m1.release()
+
 
 def teardown():
     for fname in os.listdir(os.curdir):