new way

Author: mxschmitt

playwright/_impl/_transport.py

@@ -118,19 +118,6 @@ async def connect(self) -> None:
         if sys.platform == "win32" and sys.stdout is None:
             creationflags = subprocess.CREATE_NO_WINDOW
 
-        # In Python 3.7, self._proc.wait() hangs because it does not use ThreadedChildWatcher
-        # which is used in Python 3.8+. This is unix specific and also takes care about
-        # cleaning up zombie processes. See https://bugs.python.org/issue35621
-        if (
-            sys.version_info[0] == 3
-            and sys.version_info[1] == 7
-            and sys.platform != "win32"
-            and isinstance(asyncio.get_child_watcher(), asyncio.SafeChildWatcher)
-        ):
-            from ._py37ThreadedChildWatcher import ThreadedChildWatcher  # type: ignore
-
-            watcher = ThreadedChildWatcher()
-            asyncio.set_child_watcher(watcher)
         try:
             # For pyinstaller
             env = get_driver_env()

playwright/sync_api/_context_manager.py

@@ -13,7 +13,8 @@
 # limitations under the License.
 
 import asyncio
-from typing import Any
+import sys
+from typing import Any, Optional
 
 from greenlet import greenlet
 
@@ -31,6 +32,7 @@ def __init__(self) -> None:
         self._playwright: SyncPlaywright
         self._loop: asyncio.AbstractEventLoop
         self._own_loop = False
+        self._watcher: Optional[asyncio.AbstractChildWatcher] = None
 
     def __enter__(self) -> SyncPlaywright:
         try:
@@ -44,6 +46,20 @@ def __enter__(self) -> SyncPlaywright:
 Please use the Async API instead."""
             )
 
+        # In Python 3.7, asyncio.Process.wait() hangs because it does not use ThreadedChildWatcher
+        # which is used in Python 3.8+. This is unix specific and also takes care about
+        # cleaning up zombie processes. See https://bugs.python.org/issue35621
+        if (
+            sys.version_info[0] == 3
+            and sys.version_info[1] == 7
+            and sys.platform != "win32"
+            and isinstance(asyncio.get_child_watcher(), asyncio.SafeChildWatcher)
+        ):
+            from ._py37ThreadedChildWatcher import ThreadedChildWatcher  # type: ignore
+
+            self._watcher = ThreadedChildWatcher()
+            asyncio.set_child_watcher(self._watcher)  # type: ignore
+
         def greenlet_main() -> None:
             self._loop.run_until_complete(self._connection.run_as_sync())
 
@@ -73,6 +89,8 @@ def start(self) -> SyncPlaywright:
 
     def __exit__(self, *args: Any) -> None:
         self._connection.stop_sync()
+        if self._watcher:
+            self._watcher.close()
         if self._own_loop:
             self._loop.run_until_complete(self._loop.shutdown_asyncgens())
             self._loop.close()