refactor: Utilise ctypes instead of hooking on global/local trace

Author: caffeine-addictt

src/thread/thread.py

@@ -11,6 +11,7 @@ class ParallelProcessing: ...
 
 import sys
 import time
+import ctypes
 import signal
 import threading
 from functools import wraps
@@ -116,23 +117,29 @@ def _wrap_target(
     def wrapper(
       *args: _Target_P.args, **kwargs: _Target_P.kwargs
       ) -> Union[_Target_T, None]:
-      self.status = 'Running'
+      try:
+        self.status = 'Running'
 
-      global Threads
-      Threads.add(self)
+        global Threads
+        Threads.add(self)
 
-      try:
-        self._returned_value = target(*args, **kwargs)
-      except Exception as e:
-        if not any(isinstance(e, ignore) for ignore in self.ignore_errors):
-          self.status = 'Errored'
-          self.errors.append(e)
-          return
+        try:
+          self._returned_value = target(*args, **kwargs)
+        except Exception as e:
+          if not any(isinstance(e, ignore) for ignore in self.ignore_errors):
+            self.status = 'Errored'
+            self.errors.append(e)
+            return
+
+        self.status = 'Invoking hooks'
+        self._invoke_hooks()
+        Threads.remove(self)
+        self.status = 'Completed'
 
-      self.status = 'Invoking hooks'
-      self._invoke_hooks()
-      Threads.remove(self)
-      self.status = 'Completed'
+      except SystemExit:
+        self.status = 'Killed'
+        print('KILLED ident: %s' % self.ident)
+        return
 
     return wrapper
 
@@ -157,27 +164,6 @@ def _handle_exceptions(self) -> None:
     for e in self.errors:
       raise e
 
-  def global_trace(self, frame, event: str, arg) -> Optional[Callable]:
-    if event == 'call':
-      return self.local_trace
-
-  def local_trace(self, frame, event: str, arg):
-    if self.status == 'Kill Scheduled' and event == 'line':
-      print('KILLED ident: %s' % self.ident)
-      self.status = 'Killed'
-      raise SystemExit()
-    return self.local_trace
-
-  def _run_with_trace(self) -> None:
-    """This will replace `threading.Thread`'s `run()` method"""
-    if not self._run:
-      raise exceptions.ThreadNotInitializedError(
-        'Running `_run_with_trace` may cause unintended behaviour, run `start` instead'
-      )
-
-    sys.settrace(self.global_trace)
-    self._run()
-
   @property
   def result(self) -> _Target_T:
     """
@@ -285,6 +271,20 @@ def kill(self, yielding: bool = False, timeout: float = 5) -> bool:
       raise exceptions.ThreadNotRunningError()
 
     self.status = 'Kill Scheduled'
+    res: int = ctypes.pythonapi.PyThreadState_SetAsyncExc(
+      ctypes.c_long(self.ident), ctypes.py_object(SystemExit)
+    )
+
+    if res == 0:
+      raise ValueError('Thread IDENT does not exist')
+    elif res > 1:
+      # Unexpected behaviour, something seriously went wrong
+      # https://docs.python.org/3/c-api/init.html#c.PyThreadState_SetAsyncExc
+      ctypes.pythonapi.PyThreadState_SetAsyncExc(self.ident, None)
+      raise SystemError(
+        f'Killing thread with ident [{self.ident}] failed!\nPyThreadState_SetAsyncExc returned: {res}'
+      )
+
     if not yielding:
       return True
 
@@ -308,8 +308,6 @@ def start(self) -> None:
     if self.is_alive():
       raise exceptions.ThreadStillRunningError()
 
-    self._run = self.run
-    self.run = self._run_with_trace
     super().start()