Fix memory leak in `ExclusiveResourceProcessor.__exit__`

The ``_resource_timestamps`` class-level dict was never cleaned up
when ``__exit__`` was called on the primary processor, causing stale
entries to accumulate over the lifetime of the process. Add cleanup of
``_resource_timestamps`` in ``__exit__`` and corresponding unit tests.

Closes-Bug: #2146426
Signed-off-by: Rodolfo Alonso Hernandez <ralonsoh@redhat.com>
Change-Id: If345911483f7a15965c475dd4bbb6c3f5dc1df89

neutron/agent/common/resource_processing_queue.py

@@ -124,6 +124,7 @@ class ExclusiveResourceProcessor:
     def __exit__(self, type, value, traceback):
         if self._i_am_primary():
             del self._primaries[self._id]
+            self._resource_timestamps.pop(self._id, None)
 
     def _get_resource_data_timestamp(self):
         return self._resource_timestamps.get(self._id,

neutron/tests/unit/agent/common/test_resource_processing_queue.py

@@ -76,6 +76,29 @@ class TestExclusiveResourceProcessor(base.BaseTestCase):
         primary.__exit__(None, None, None)
         self.assertNotIn(FAKE_ID, queue.ExclusiveResourceProcessor._primaries)
 
+    def test__exit__cleans_resource_timestamps(self):
+        with queue.ExclusiveResourceProcessor(FAKE_ID) as primary:
+            primary.fetched_and_processed(timeutils.utcnow())
+            self.assertIn(
+                FAKE_ID,
+                queue.ExclusiveResourceProcessor._resource_timestamps)
+        self.assertNotIn(
+            FAKE_ID,
+            queue.ExclusiveResourceProcessor._resource_timestamps)
+
+    def test__exit__non_primary_does_not_clean_resource_timestamps(self):
+        primary = queue.ExclusiveResourceProcessor(FAKE_ID)
+        primary.fetched_and_processed(timeutils.utcnow())
+        not_primary = queue.ExclusiveResourceProcessor(FAKE_ID)
+        not_primary.__exit__(None, None, None)
+        self.assertIn(
+            FAKE_ID,
+            queue.ExclusiveResourceProcessor._resource_timestamps)
+        primary.__exit__(None, None, None)
+        self.assertNotIn(
+            FAKE_ID,
+            queue.ExclusiveResourceProcessor._resource_timestamps)
+
     def test_data_fetched_since(self):
         primary = queue.ExclusiveResourceProcessor(FAKE_ID)
         self.assertEqual(datetime.datetime.min,

releasenotes/notes/fix-memory-leak-exclusive-resource-processor-8a9de52d79218323.yaml

@@ -0,0 +1,7 @@
+---
+fixes:
+  - |
+    Fixed a memory leak in ``ExclusiveResourceProcessor`` where the
+    ``_resource_timestamps`` class-level dictionary was never cleaned up
+    when the primary processor exited. Over time, this caused stale
+    entries to accumulate for every resource ID that was ever processed.