是否有可能终止一个正在运行的线程而不设置/检查任何标志/信号/等等?
当前回答
Python版本:3.8
使用守护线程来执行我们想要的,如果我们想要终止守护线程,我们只需要让父线程退出,然后系统就会终止父线程创建的守护线程。
还支持协程和协程函数。
def main():
start_time = time.perf_counter()
t1 = ExitThread(time.sleep, (10,), debug=False)
t1.start()
time.sleep(0.5)
t1.exit()
try:
print(t1.result_future.result())
except concurrent.futures.CancelledError:
pass
end_time = time.perf_counter()
print(f"time cost {end_time - start_time:0.2f}")
下面是ExitThread源代码
import concurrent.futures
import threading
import typing
import asyncio
class _WorkItem(object):
""" concurrent\futures\thread.py
"""
def __init__(self, future, fn, args, kwargs, *, debug=None):
self._debug = debug
self.future = future
self.fn = fn
self.args = args
self.kwargs = kwargs
def run(self):
if self._debug:
print("ExitThread._WorkItem run")
if not self.future.set_running_or_notify_cancel():
return
try:
coroutine = None
if asyncio.iscoroutinefunction(self.fn):
coroutine = self.fn(*self.args, **self.kwargs)
elif asyncio.iscoroutine(self.fn):
coroutine = self.fn
if coroutine is None:
result = self.fn(*self.args, **self.kwargs)
else:
result = asyncio.run(coroutine)
if self._debug:
print("_WorkItem done")
except BaseException as exc:
self.future.set_exception(exc)
# Break a reference cycle with the exception 'exc'
self = None
else:
self.future.set_result(result)
class ExitThread:
""" Like a stoppable thread
Using coroutine for target then exit before running may cause RuntimeWarning.
"""
def __init__(self, target: typing.Union[typing.Coroutine, typing.Callable] = None
, args=(), kwargs={}, *, daemon=None, debug=None):
#
self._debug = debug
self._parent_thread = threading.Thread(target=self._parent_thread_run, name="ExitThread_parent_thread"
, daemon=daemon)
self._child_daemon_thread = None
self.result_future = concurrent.futures.Future()
self._workItem = _WorkItem(self.result_future, target, args, kwargs, debug=debug)
self._parent_thread_exit_lock = threading.Lock()
self._parent_thread_exit_lock.acquire()
self._parent_thread_exit_lock_released = False # When done it will be True
self._started = False
self._exited = False
self.result_future.add_done_callback(self._release_parent_thread_exit_lock)
def _parent_thread_run(self):
self._child_daemon_thread = threading.Thread(target=self._child_daemon_thread_run
, name="ExitThread_child_daemon_thread"
, daemon=True)
self._child_daemon_thread.start()
# Block manager thread
self._parent_thread_exit_lock.acquire()
self._parent_thread_exit_lock.release()
if self._debug:
print("ExitThread._parent_thread_run exit")
def _release_parent_thread_exit_lock(self, _future):
if self._debug:
print(f"ExitThread._release_parent_thread_exit_lock {self._parent_thread_exit_lock_released} {_future}")
if not self._parent_thread_exit_lock_released:
self._parent_thread_exit_lock_released = True
self._parent_thread_exit_lock.release()
def _child_daemon_thread_run(self):
self._workItem.run()
def start(self):
if self._debug:
print(f"ExitThread.start {self._started}")
if not self._started:
self._started = True
self._parent_thread.start()
def exit(self):
if self._debug:
print(f"ExitThread.exit exited: {self._exited} lock_released: {self._parent_thread_exit_lock_released}")
if self._parent_thread_exit_lock_released:
return
if not self._exited:
self._exited = True
if not self.result_future.cancel():
if self.result_future.running():
self.result_future.set_exception(concurrent.futures.CancelledError())
其他回答
这是一个糟糕的答案,请看评论
以下是如何做到这一点:
from threading import *
...
for thread in enumerate():
if thread.isAlive():
try:
thread._Thread__stop()
except:
print(str(thread.getName()) + ' could not be terminated'))
给它几秒钟,然后你的线程应该停止。还要检查thread._Thread__delete()方法。
为了方便,我建议使用thread.quit()方法。例如,如果你的线程中有一个套接字,我建议在你的套接字句柄类中创建一个quit()方法,终止套接字,然后在你的quit()中运行一个thread. _thread__stop()。
Python版本:3.8
使用守护线程来执行我们想要的,如果我们想要终止守护线程,我们只需要让父线程退出,然后系统就会终止父线程创建的守护线程。
还支持协程和协程函数。
def main():
start_time = time.perf_counter()
t1 = ExitThread(time.sleep, (10,), debug=False)
t1.start()
time.sleep(0.5)
t1.exit()
try:
print(t1.result_future.result())
except concurrent.futures.CancelledError:
pass
end_time = time.perf_counter()
print(f"time cost {end_time - start_time:0.2f}")
下面是ExitThread源代码
import concurrent.futures
import threading
import typing
import asyncio
class _WorkItem(object):
""" concurrent\futures\thread.py
"""
def __init__(self, future, fn, args, kwargs, *, debug=None):
self._debug = debug
self.future = future
self.fn = fn
self.args = args
self.kwargs = kwargs
def run(self):
if self._debug:
print("ExitThread._WorkItem run")
if not self.future.set_running_or_notify_cancel():
return
try:
coroutine = None
if asyncio.iscoroutinefunction(self.fn):
coroutine = self.fn(*self.args, **self.kwargs)
elif asyncio.iscoroutine(self.fn):
coroutine = self.fn
if coroutine is None:
result = self.fn(*self.args, **self.kwargs)
else:
result = asyncio.run(coroutine)
if self._debug:
print("_WorkItem done")
except BaseException as exc:
self.future.set_exception(exc)
# Break a reference cycle with the exception 'exc'
self = None
else:
self.future.set_result(result)
class ExitThread:
""" Like a stoppable thread
Using coroutine for target then exit before running may cause RuntimeWarning.
"""
def __init__(self, target: typing.Union[typing.Coroutine, typing.Callable] = None
, args=(), kwargs={}, *, daemon=None, debug=None):
#
self._debug = debug
self._parent_thread = threading.Thread(target=self._parent_thread_run, name="ExitThread_parent_thread"
, daemon=daemon)
self._child_daemon_thread = None
self.result_future = concurrent.futures.Future()
self._workItem = _WorkItem(self.result_future, target, args, kwargs, debug=debug)
self._parent_thread_exit_lock = threading.Lock()
self._parent_thread_exit_lock.acquire()
self._parent_thread_exit_lock_released = False # When done it will be True
self._started = False
self._exited = False
self.result_future.add_done_callback(self._release_parent_thread_exit_lock)
def _parent_thread_run(self):
self._child_daemon_thread = threading.Thread(target=self._child_daemon_thread_run
, name="ExitThread_child_daemon_thread"
, daemon=True)
self._child_daemon_thread.start()
# Block manager thread
self._parent_thread_exit_lock.acquire()
self._parent_thread_exit_lock.release()
if self._debug:
print("ExitThread._parent_thread_run exit")
def _release_parent_thread_exit_lock(self, _future):
if self._debug:
print(f"ExitThread._release_parent_thread_exit_lock {self._parent_thread_exit_lock_released} {_future}")
if not self._parent_thread_exit_lock_released:
self._parent_thread_exit_lock_released = True
self._parent_thread_exit_lock.release()
def _child_daemon_thread_run(self):
self._workItem.run()
def start(self):
if self._debug:
print(f"ExitThread.start {self._started}")
if not self._started:
self._started = True
self._parent_thread.start()
def exit(self):
if self._debug:
print(f"ExitThread.exit exited: {self._exited} lock_released: {self._parent_thread_exit_lock_released}")
if self._parent_thread_exit_lock_released:
return
if not self._exited:
self._exited = True
if not self.result_future.cancel():
if self.result_future.running():
self.result_future.set_exception(concurrent.futures.CancelledError())
如果不杀死线程会更好。 一种方法是在线程的循环中引入一个“try”块,并在想要停止线程时抛出一个异常(例如break/return/…)这会让你停下来/一会儿/…)。 我在我的应用程序上使用了这个,它是有效的…
可以通过在将退出线程的线程中安装trace来终止线程。请参阅所附的链接,了解一种可能的实现。
在Python中杀死一个线程
正如@Kozyarchuk的回答中提到的,安装跟踪工作。由于这个答案不包含代码,下面是一个工作就绪的示例:
import sys, threading, time
class TraceThread(threading.Thread):
def __init__(self, *args, **keywords):
threading.Thread.__init__(self, *args, **keywords)
self.killed = False
def start(self):
self._run = self.run
self.run = self.settrace_and_run
threading.Thread.start(self)
def settrace_and_run(self):
sys.settrace(self.globaltrace)
self._run()
def globaltrace(self, frame, event, arg):
return self.localtrace if event == 'call' else None
def localtrace(self, frame, event, arg):
if self.killed and event == 'line':
raise SystemExit()
return self.localtrace
def f():
while True:
print('1')
time.sleep(2)
print('2')
time.sleep(2)
print('3')
time.sleep(2)
t = TraceThread(target=f)
t.start()
time.sleep(2.5)
t.killed = True
它在输出1和2之后停止。3不打印。
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