Merge pull request aws#211 from aws/fix/lazy-loading-mc-utils

Lazy load multi-concurrent utilities for cold start improvement

Author: darklight3it

awslambdaric/__main__.py

@@ -6,7 +6,6 @@
 
 from .lambda_config import LambdaConfigProvider
 from .lambda_runtime_client import LambdaRuntimeClient
-from .lambda_multi_concurrent_utils import MultiConcurrentRunner
 from . import bootstrap
 
 
@@ -20,6 +19,9 @@ def main(args):
         # Multi-concurrent mode: redirect fork, stdout/stderr and run
         max_conc = int(config.max_concurrency)
         socket_path = config.lmi_socket_path
+
+        from .lambda_multi_concurrent_utils import MultiConcurrentRunner
+
         MultiConcurrentRunner.run_concurrent(
             handler, api_addr, use_thread, socket_path, max_conc
         )

tests/test_main.py

@@ -9,11 +9,12 @@
 
 
 class TestMain(unittest.TestCase):
+    @patch("awslambdaric.lambda_multi_concurrent_utils.MultiConcurrentRunner")
     @patch("awslambdaric.__main__.bootstrap")
     @patch("awslambdaric.__main__.LambdaRuntimeClient")
     @patch("awslambdaric.__main__.LambdaConfigProvider")
     def test_default_path_invokes_runtime_client_and_bootstrap(
-        self, mock_config_provider, mock_client_cls, mock_bootstrap
+        self, mock_config_provider, mock_client_cls, mock_bootstrap, mock_runner
     ):
         # Non-multi-concurrent mode
         cfg = MagicMock()
@@ -30,7 +31,9 @@ def test_default_path_invokes_runtime_client_and_bootstrap(
             "my.handler", mock_client_cls.return_value
         )
 
-    @patch("awslambdaric.__main__.MultiConcurrentRunner")
+        mock_runner.run_concurrent.assert_not_called()
+
+    @patch("awslambdaric.lambda_multi_concurrent_utils.MultiConcurrentRunner")
     @patch("awslambdaric.__main__.LambdaConfigProvider")
     def test_multi_concurrent_path_dispatches_to_multi_concurrent_runner(
         self, mock_config_provider, mock_runner