Fixed leaked semaphores for dashboard when using MacOS

mpire/dashboard/dashboard.py

@@ -1,6 +1,9 @@
+import atexit
 import getpass
 import importlib.resources
 import logging
+import os
+import signal
 import socket
 from datetime import datetime
 from multiprocessing import Event, Process
@@ -11,7 +14,6 @@
 from markupsafe import escape
 from werkzeug.serving import make_server
 
-from mpire.signal import DisableKeyboardInterruptSignal, ignore_keyboard_interrupt
 from mpire.dashboard.manager import (DASHBOARD_MANAGER_CONNECTION_DETAILS,
                                      get_manager_client_dicts, shutdown_manager_server, start_manager_server)
 from mpire.dashboard.utils import get_two_available_ports
@@ -117,35 +119,34 @@ def start_dashboard(port_range: Sequence = range(8080, 8100)) -> Dict[str, Union
 
         dashboard_port_nr, manager_port_nr = get_two_available_ports(port_range)
 
-        # Prevent signal from propagating to child process
-        with DisableKeyboardInterruptSignal():
+        # Set up manager server
+        _DASHBOARD_MANAGER = start_manager_server(manager_port_nr)
 
-            # Set up manager server
-            _DASHBOARD_MANAGER = start_manager_server(manager_port_nr)
+        # Start flask server
+        logging.getLogger('werkzeug').setLevel(logging.WARN)
+        _server_process = Process(target=_run, args=(DASHBOARD_STARTED_EVENT, dashboard_port_nr, 
+                                                        get_manager_client_dicts()),
+                                    daemon=True, name='dashboard-process')
+        _server_process.start()
+        DASHBOARD_STARTED_EVENT.wait()
 
-            # Start flask server
-            logging.getLogger('werkzeug').setLevel(logging.WARN)
-            _server_process = Process(target=_run, args=(DASHBOARD_STARTED_EVENT, dashboard_port_nr, 
-                                                         get_manager_client_dicts()),
-                                      daemon=True, name='dashboard-process')
-            _server_process.start()
-            DASHBOARD_STARTED_EVENT.wait()
-
-            # Return connect information
-            return {'dashboard_port_nr': dashboard_port_nr,
-                    'manager_host': DASHBOARD_MANAGER_CONNECTION_DETAILS.host or socket.gethostname(),
-                    'manager_port_nr': DASHBOARD_MANAGER_CONNECTION_DETAILS.port}
+        # Return connect information
+        return {'dashboard_port_nr': dashboard_port_nr,
+                'manager_host': DASHBOARD_MANAGER_CONNECTION_DETAILS.host or socket.gethostname(),
+                'manager_port_nr': DASHBOARD_MANAGER_CONNECTION_DETAILS.port}
 
     else:
         raise RuntimeError("You already have a running dashboard")
 
 
+@atexit.register
 def shutdown_dashboard() -> None:
     """ Shuts down the dashboard """
     if DASHBOARD_STARTED_EVENT.is_set():
         global _server_process, _DASHBOARD_MANAGER, _DASHBOARD_TQDM_DICT, _DASHBOARD_TQDM_DETAILS_DICT
         if _server_process is not None:
-            _server_process.terminate()
+            # Send SIGINT to the server process, which is the only way to stop it without causing semaphore leaks
+            os.kill(_server_process.pid, signal.SIGINT)
             _server_process.join()
         shutdown_manager_server(_DASHBOARD_MANAGER)
         _DASHBOARD_MANAGER = None
@@ -190,8 +191,6 @@ def _run(started: Event, dashboard_port_nr: int, manager_client_dicts: Tuple[Bas
     :param manager_port_nr: Dashboard manager port number
     :param dashboard_port_nr: Dashboard port number
     """
-    ignore_keyboard_interrupt()  # For Windows compatibility
-
     global _DASHBOARD_TQDM_DICT, _DASHBOARD_TQDM_DETAILS_DICT
     _DASHBOARD_TQDM_DICT, _DASHBOARD_TQDM_DETAILS_DICT, _ = manager_client_dicts