feat(control-client-stall): adding stall feature for control client

README.md

@@ -15,8 +15,7 @@ is expected to be used by Storage library maintainers.
   - [When to use this testbench](#when-to-use-this-testbench)
   - [How to use this testbench](#how-to-use-this-testbench)
     - [Initial set up](#initial-set-up)
-    - [Run the testbench](#run-the-testbench)
-    - [Start the gRPC server](#start-the-gRPC-server)
+    - [Start the gRPC server](#start-the-grpc-server)
     - [Check that the testbench is running](#check-that-the-testbench-is-running)
   - [Updating Proto Files](#updating-proto-files)
   - [Force Failures](#force-failures)
@@ -35,6 +34,7 @@ is expected to be used by Storage library maintainers.
     - [Delete a Retry Test resource](#delete-a-retry-test-resource)
     - [Causing a failure using x-retry-test-id header](#causing-a-failure-using-x-retry-test-id-header)
     - [Forced Failures Supported](#forced-failures-supported)
+  - [Storage Control API Stall Support](#storage-control-api-stall-support)
   - [Developing for the testbench](#developing-for-the-testbench)
     - [Writing and running tests](#writing-and-running-tests)
   - [Releasing the testbench](#releasing-the-testbench)
@@ -277,6 +277,37 @@ curl -H "x-retry-test-id: 1d05c20627844214a9ff7cbcf696317d" "http://localhost:91
 | redirect-send-token-T                     | [HTTP] Unsupported [GRPC] Testbench will fail the RPC with `ABORTED` and include appropriate redirection error details.
 | redirect-send-handle-and-token-T          | [HTTP] Unsupported [GRPC] Testbench will fail the RPC with `ABORTED` and include appropriate redirection error details.
 
+## Storage Control API Stall Support
+
+The testbench supports stall functionality for the Storage Control API (gRPC only) to test client retry behavior. All folder operations and storage layout operations can be delayed using the `x-goog-emulator-instructions` metadata header.
+
+**Supported operations:**
+- **Folder operations:** `CreateFolder`, `DeleteFolder`, `GetFolder`, `ListFolders`, `RenameFolder`
+- **Storage layout operations:** `GetStorageLayout`
+
+> **Note:** The Storage Control API uses the **same gRPC server** as the Storage API. Both services are available on the same port (e.g., port 8888 if started with `curl "http://localhost:9000/start_grpc?port=8888"`).
+
+**Supported stall instruction:**
+- `stall-for-Ns`: Stalls for N seconds (e.g., `stall-for-3s` stalls for 3 seconds)
+
+**Example usage in Python:**
+```python
+import grpc
+from google.storage.control.v2 import storage_control_pb2, storage_control_pb2_grpc
+
+# Connect to the same gRPC server port (8888) started earlier
+channel = grpc.insecure_channel('localhost:8888')
+stub = storage_control_pb2_grpc.StorageControlStub(channel)
+
+# Create folder with 2-second stall
+metadata = [('x-goog-emulator-instructions', 'stall-for-2s')]
+request = storage_control_pb2.CreateFolderRequest(
+    parent="projects/_/buckets/test-bucket",
+    folder_id="test-folder"
+)
+response = stub.CreateFolder(request, metadata=metadata)
+```
+
 ## Developing for the testbench
 
 ### Writing and running tests

google/iam/v1/iam_policy_pb2_grpc.py

@@ -1,18 +1,4 @@
 # Generated by the gRPC Python protocol compiler plugin. DO NOT EDIT!
-# Copyright 2024 Google LLC
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#     http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-
 """Client and server classes corresponding to protobuf-defined services."""
 import grpc
 import warnings

google/iam/v1/options_pb2_grpc.py

@@ -1,18 +1,4 @@
 # Generated by the gRPC Python protocol compiler plugin. DO NOT EDIT!
-# Copyright 2024 Google LLC
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#     http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-
 """Client and server classes corresponding to protobuf-defined services."""
 import grpc
 import warnings

google/iam/v1/policy_pb2_grpc.py

@@ -1,18 +1,4 @@
 # Generated by the gRPC Python protocol compiler plugin. DO NOT EDIT!
-# Copyright 2024 Google LLC
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#     http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-
 """Client and server classes corresponding to protobuf-defined services."""
 import grpc
 import warnings

google/storage/control/__init__.py

@@ -0,0 +1,13 @@
+# Copyright 2026 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.