Add logic for handling timeouts to StandardRetryStrategy

Author: SamRemis

packages/smithy-core/src/smithy_core/retries.py

@@ -268,7 +268,9 @@ def acquire(self, *, error: Exception) -> int:
         If there's insufficient capacity available, raise an exception.
         Otherwise, return the amount of capacity successfully allocated.
         """
-        capacity_amount = self.RETRY_COST
+
+        is_timeout = getattr(error, "is_timeout_error", False)
+        capacity_amount = self.TIMEOUT_RETRY_COST if is_timeout else self.RETRY_COST
 
         with self._lock:
             if capacity_amount > self._available_capacity:

packages/smithy-core/tests/unit/test_retries.py

@@ -2,6 +2,8 @@
 #  SPDX-License-Identifier: Apache-2.0
 
 import pytest
+
+from smithy_core import SmithyError
 from smithy_core.exceptions import CallError, RetryError
 from smithy_core.retries import ExponentialBackoffJitterType as EBJT
 from smithy_core.retries import (
@@ -208,3 +210,13 @@ def test_retry_quota_release_caps_at_max(
     # Release more than we acquired. Should cap at initial capacity.
     retry_quota.release(release_amount=50)
     assert retry_quota.available_capacity == 10
+
+
+def test_retry_quota_acquire_timeout_error(
+    retry_quota: StandardRetryQuota,
+) -> None:
+
+    timeout_error = CallError(is_timeout_error=True, is_retry_safe=True)
+    acquired = retry_quota.acquire(error=timeout_error)
+    assert acquired == StandardRetryQuota.TIMEOUT_RETRY_COST
+    assert retry_quota.available_capacity == 0