"""
This module contains a killable Python thread implementation
taken from http://tomerfiliba.com/recipes/Thread2/
"""
import threading
import inspect
import ctypes
__author__ = "Tomer Filiba, Georg Hinkel"
def _async_raise(tid, exctype):
"""raises the exception, performs cleanup if needed"""
if not inspect.isclass(exctype):
raise TypeError("Only types can be raised (not instances)")
res = ctypes.pythonapi.PyThreadState_SetAsyncExc(ctypes.c_long(tid), ctypes.py_object(exctype))
if res == 0:
raise ValueError("invalid thread id")
if res != 1:
# """if it returns a number greater than one, you're in trouble,
# and you should call it again with exc=NULL to revert the effect"""
ctypes.pythonapi.PyThreadState_SetAsyncExc(tid, 0)
raise SystemError("PyThreadState_SetAsyncExc failed")
[docs]class Thread(threading.Thread):
"""
This class represents a thread that can be terminated
"""
def __init__(self, *args, **kwargs):
super(Thread, self).__init__(*args, **kwargs)
self.__thread_id = None
def _get_my_tid(self):
"""determines this (self's) thread id"""
if not self.isAlive():
raise threading.ThreadError("the thread is not active")
# do we have it cached?
if self.__thread_id is not None:
return self.__thread_id
# no, look for it in the _active dict
# pylint: disable=protected-access
for tid, tobj in list(threading._active.items()):
if tobj is self:
self.__thread_id = tid
return tid
raise AssertionError("could not determine the thread's id")
[docs] def raise_exc(self, exctype):
"""raises the given exception type in the context of this thread"""
_async_raise(self._get_my_tid(), exctype)
[docs] def terminate(self):
"""raises SystemExit in the context of the given thread, which should
cause the thread to exit silently (unless caught)"""
self.raise_exc(SystemExit)