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())

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

另一种方法是使用signal.pthread_kill发送一个停止信号。

from signal import pthread_kill, SIGTSTP
from threading import Thread
from itertools import count
from time import sleep

def target():
    for num in count():
        print(num)
        sleep(1)

thread = Thread(target=target)
thread.start()
sleep(5)
pthread_kill(thread.ident, SIGTSTP)

结果

0
1
2
3
4

[14]+  Stopped

多处理。进程可以p.terminate()

如果我想杀死一个线程，但不想使用标志/锁/信号/信号量/事件/任何东西，我就把线程提升到完整的进程。对于只使用几个线程的代码，开销并没有那么糟糕。

例如，这可以方便地终止执行阻塞I/O的助手“线程”

转换很简单:在相关代码中替换所有线程。多线程线程。进程和所有队列。多处理队列。排队并将p.t terminate()所需的调用添加到想要杀死子进程p的父进程中

关于多处理，请参阅Python文档。

例子:

import multiprocessing
proc = multiprocessing.Process(target=your_proc_function, args=())
proc.start()
# Terminate the process
proc.terminate()  # sends a SIGTERM

正如其他人所提到的，规范是设置一个停止标志。对于一些轻量级的东西(没有Thread的子类化，没有全局变量)，lambda回调是一个选项。(注意if stop()中的括号。)

import threading
import time

def do_work(id, stop):
    print("I am thread", id)
    while True:
        print("I am thread {} doing something".format(id))
        if stop():
            print("  Exiting loop.")
            break
    print("Thread {}, signing off".format(id))


def main():
    stop_threads = False
    workers = []
    for id in range(0,3):
        tmp = threading.Thread(target=do_work, args=(id, lambda: stop_threads))
        workers.append(tmp)
        tmp.start()
    time.sleep(3)
    print('main: done sleeping; time to stop the threads.')
    stop_threads = True
    for worker in workers:
        worker.join()
    print('Finis.')

if __name__ == '__main__':
    main()

将print()替换为始终刷新的pr()函数(sys.stdout.flush())可以提高shell输出的精度。

(仅在Windows/Eclipse/Python3.3上测试)

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…