From 477b838940942572cb4fd3bce8eb0aeb3cb5008f Mon Sep 17 00:00:00 2001
From: Jakob Keller <57402305+jakob-keller@users.noreply.github.com>
Date: Tue, 16 Jan 2024 20:19:01 +0100
Subject: [PATCH] fix race condition in S3 Express identity cache (closes
 #1072)

---
 CHANGES.rst             |  4 ++++
 aiobotocore/__init__.py |  2 +-
 aiobotocore/utils.py    | 22 ++++------------------
 3 files changed, 9 insertions(+), 19 deletions(-)

diff --git a/CHANGES.rst b/CHANGES.rst
index b5e9c4f9..5470aa8f 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -1,6 +1,10 @@
 Changes
 -------
 
+2.9.1 (2024-01-16)
+^^^^^^^^^^^^^^^^^^
+* fix race condition in S3 Express identity cache #1072
+
 2.9.0 (2023-12-12)
 ^^^^^^^^^^^^^^^^^^
 * bump botocore dependency specification
diff --git a/aiobotocore/__init__.py b/aiobotocore/__init__.py
index 387cfacc..b03f5b5d 100644
--- a/aiobotocore/__init__.py
+++ b/aiobotocore/__init__.py
@@ -1 +1 @@
-__version__ = '2.9.0'
+__version__ = '2.9.1'
diff --git a/aiobotocore/utils.py b/aiobotocore/utils.py
index 3163bafd..f7df88f1 100644
--- a/aiobotocore/utils.py
+++ b/aiobotocore/utils.py
@@ -367,30 +367,16 @@ async def get_credentials(self, **kwargs):
 
 
 class AioS3ExpressIdentityCache(AioIdentityCache, S3ExpressIdentityCache):
-    @functools.cached_property
-    def _aio_credential_cache(self):
-        """Substitutes upstream credential cache."""
-        return {}
+    @functools.lru_cache(maxsize=100)
+    def _get_credentials(self, bucket):
+        return asyncio.create_task(super().get_credentials(bucket=bucket))
 
     async def get_credentials(self, bucket):
         # upstream uses `@functools.lru_cache(maxsize=100)` to cache credentials.
         # This is incompatible with async code.
         # We need to implement custom caching logic.
 
-        if (credentials := self._aio_credential_cache.get(bucket)) is None:
-            # cache miss -> get credentials asynchronously
-            credentials = await super().get_credentials(bucket=bucket)
-
-            # upstream cache is bounded at 100 entries
-            if len(self._aio_credential_cache) >= 100:
-                # drop oldest entry from cache (deviates from lru_cache logic)
-                self._aio_credential_cache.pop(
-                    next(iter(self._aio_credential_cache)),
-                )
-
-            self._aio_credential_cache[bucket] = credentials
-
-        return credentials
+        return await self._get_credentials(bucket=bucket)
 
     def build_refresh_callback(self, bucket):
         async def refresher():