+ Error handling in graceful shutdown

Author: caffeine-addictt

src/thread/thread.py

@@ -30,6 +30,7 @@
 Overflow_In = Any
 
 
+Threads: set['Thread'] = set()
 class Thread(threading.Thread):
   """
   Wraps python's `threading.Thread` class
@@ -108,6 +109,9 @@ def _wrap_target(self, target: Callable[..., Data_Out]) -> Callable[..., Data_Ou
     def wrapper(*args: Any, **kwargs: Any) -> Any:
       self.status = 'Running'
 
+      global Threads
+      Threads.add(self)
+
       try:
         self.returned_value = target(*args, **kwargs)
       except Exception as e:
@@ -118,6 +122,7 @@ def wrapper(*args: Any, **kwargs: Any) -> Any:
 
       self.status = 'Invoking hooks'
       self._invoke_hooks()
+      Threads.remove(self)
       self.status = 'Completed'
     return wrapper
 
@@ -156,7 +161,7 @@ def global_trace(self, frame, event: str, arg) -> Optional[Callable]:
 
   def local_trace(self, frame, event: str, arg):
     if self.status == 'Kill Scheduled' and event == 'line':
-      print('KILLED ident:%s' % self.ident)
+      print('KILLED ident: %s' % self.ident)
       self.status = 'Killed'
       raise SystemExit()
     return self.local_trace
@@ -524,9 +529,14 @@ def service_shutdown(signum, frame):
     print('\nCaught signal %d' % signum)
     print('Gracefully killing active threads')
 
-    for thread in threading.enumerate():
+    for thread in Threads:
       if isinstance(thread, Thread):
-        thread.kill()
+        try:
+          thread.kill()
+        except (exceptions.ThreadNotRunningError, exceptions.ThreadNotInitializedError):
+          pass
+        except Exception as e:
+          print('Failed to kill ident: %d' % thread.ident or 0)
     sys.exit(0)