feat: avoid long running process when request timeout (#309)

Previously function framework use 0 timeout which is actually "no timeout" restrction.
 This was causing a problem that when user provides a request timeout to Cloud function, process will still continue and consume resources.
 In this fix, timeout is enabled; default timeout settings is 5 min, same as Cloud run.
 To make sure timeout settings will be respected, default settings switched from multi-threads to multi-workers.

 However, user is still allowed to  customize workers/threads by assigning env var. But user need to note that timeout won't work when #thread > 1.

src/functions_framework/__init__.py

@@ -65,9 +65,9 @@ def write(self, out):
 
 def cloud_event(func: CloudEventFunction) -> CloudEventFunction:
     """Decorator that registers cloudevent as user function signature type."""
-    _function_registry.REGISTRY_MAP[
-        func.__name__
-    ] = _function_registry.CLOUDEVENT_SIGNATURE_TYPE
+    _function_registry.REGISTRY_MAP[func.__name__] = (
+        _function_registry.CLOUDEVENT_SIGNATURE_TYPE
+    )
 
     @functools.wraps(func)
     def wrapper(*args, **kwargs):
@@ -105,9 +105,9 @@ def wrapper(*args, **kwargs):
 
 def http(func: HTTPFunction) -> HTTPFunction:
     """Decorator that registers http as user function signature type."""
-    _function_registry.REGISTRY_MAP[
-        func.__name__
-    ] = _function_registry.HTTP_SIGNATURE_TYPE
+    _function_registry.REGISTRY_MAP[func.__name__] = (
+        _function_registry.HTTP_SIGNATURE_TYPE
+    )
 
     @functools.wraps(func)
     def wrapper(*args, **kwargs):

src/functions_framework/_http/gunicorn.py

@@ -21,14 +21,15 @@ class GunicornApplication(gunicorn.app.base.BaseApplication):
     def __init__(self, app, host, port, debug, **options):
         self.options = {
             "bind": "%s:%s" % (host, port),
-            "workers": 1,
-            "threads": (os.cpu_count() or 1) * 4,
-            "timeout": 0,
+            "workers": os.environ.get("WORKERS", (os.cpu_count() or 1) * 4),
+            "threads": os.environ.get("THREADS", 1),
+            "timeout": os.environ.get("CLOUD_RUN_TIMEOUT_SECONDS", 300),
             "loglevel": "error",
             "limit_request_line": 0,
         }
         self.options.update(options)
         self.app = app
+
         super().__init__()
 
     def load_config(self):

src/functions_framework/_typed_event.py

@@ -48,9 +48,9 @@ def register_typed_event(decorator_type, func):
         )
 
     _function_registry.INPUT_TYPE_MAP[func.__name__] = input_type
-    _function_registry.REGISTRY_MAP[
-        func.__name__
-    ] = _function_registry.TYPED_SIGNATURE_TYPE
+    _function_registry.REGISTRY_MAP[func.__name__] = (
+        _function_registry.TYPED_SIGNATURE_TYPE
+    )
 
 
 """ Checks whether the response type of the typed function has a to_dict method"""

tests/test_http.py

@@ -97,17 +97,17 @@ def test_gunicorn_application(debug):
     assert gunicorn_app.app == app
     assert gunicorn_app.options == {
         "bind": "%s:%s" % (host, port),
-        "workers": 1,
-        "threads": os.cpu_count() * 4,
-        "timeout": 0,
+        "workers": os.cpu_count() * 4,
+        "threads": 1,
+        "timeout": 300,
         "loglevel": "error",
         "limit_request_line": 0,
     }
 
     assert gunicorn_app.cfg.bind == ["1.2.3.4:1234"]
-    assert gunicorn_app.cfg.workers == 1
-    assert gunicorn_app.cfg.threads == os.cpu_count() * 4
-    assert gunicorn_app.cfg.timeout == 0
+    assert gunicorn_app.cfg.workers == os.cpu_count() * 4
+    assert gunicorn_app.cfg.threads == 1
+    assert gunicorn_app.cfg.timeout == 300
     assert gunicorn_app.load() == app