Allow fork in limited cases (#2624)

tests/worker/test_manager.py

@@ -1,13 +1,20 @@
 from logging import ERROR, INFO
-from signal import SIGINT, SIGKILL
+from signal import SIGINT
 from unittest.mock import Mock, call, patch
 
 import pytest
 
+from sanic.compat import OS_IS_WINDOWS
 from sanic.exceptions import ServerKilled
 from sanic.worker.manager import WorkerManager
 
 
+if not OS_IS_WINDOWS:
+    from signal import SIGKILL
+else:
+    SIGKILL = SIGINT
+
+
 def fake_serve():
     ...
 

tests/worker/test_multiplexer.py

@@ -1,3 +1,5 @@
+import sys
+
 from multiprocessing import Event
 from os import environ, getpid
 from typing import Any, Dict, Type, Union
@@ -6,6 +8,7 @@ from unittest.mock import Mock
 import pytest
 
 from sanic import Sanic
+from sanic.compat import use_context
 from sanic.worker.multiplexer import WorkerMultiplexer
 from sanic.worker.state import WorkerState
 
@@ -28,6 +31,10 @@ def m(monitor_publisher, worker_state):
     del environ["SANIC_WORKER_NAME"]
 
 
+@pytest.mark.skipif(
+    sys.platform not in ("linux", "darwin"),
+    reason="This test requires fork context",
+)
 def test_has_multiplexer_default(app: Sanic):
     event = Event()
 
@@ -41,7 +48,8 @@ def test_has_multiplexer_default(app: Sanic):
             app.shared_ctx.event.set()
         app.stop()
 
-    app.run()
+    with use_context("fork"):
+        app.run()
 
     assert event.is_set()
 

tests/worker/test_startup.py

@@ -0,0 +1,25 @@
+from unittest.mock import patch
+
+import pytest
+
+from sanic import Sanic
+
+
+@pytest.mark.parametrize(
+    "start_method,platform,expected",
+    (
+        (None, "linux", "spawn"),
+        (None, "other", "spawn"),
+        ("fork", "linux", "fork"),
+        ("fork", "other", "fork"),
+        ("forkserver", "linux", "forkserver"),
+        ("forkserver", "other", "forkserver"),
+        ("spawn", "linux", "spawn"),
+        ("spawn", "other", "spawn"),
+    ),
+)
+def test_get_context(start_method, platform, expected):
+    if start_method:
+        Sanic.start_method = start_method
+    with patch("sys.platform", platform):
+        assert Sanic._get_startup_method() == expected