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python - 结束包含无限循环的线程

问题描述

在检测到运动后，我正在尝试使用 python 打开一些 RGB 灯。我的代码在下面，但我无法让线程结束并关闭 LED。所有发生的事情都是我在键盘中断后卡住了。

基本上，当我运行代码时，它可以检测运动并打开灯，但是当我尝试以键盘中断异常结束程序时，程序挂起并且没有停止，或者它停止但 LED 没有关闭并保持点亮。我查看了有关如何停止线程运行的各个页面，但没有一个有帮助。下面是我看过的文章。我认为我的问题是运行照明模式循环的线程没有停止，所以当我尝试关闭每个 LED 时，它会立即重新打开，但我不确定。

我无法让线程停止我尝试过的任何方式。任何帮助将非常感激。

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""
Created on Wed Jan  1 10:10:25 2020

@author: thomas
"""

import RPi.GPIO as GPIO
import time
import subprocess
import argparse
from neopixel import *
import datetime as dt
from threading import Thread
from threading import enumerate
from threading import Event as EV
import sys

global stop

GPIO.setmode(GPIO.BCM)

# LED strip configuration:

LED_COUNT      = 288      # Number of LED pixels.
LED_PIN        = 18      # GPIO pin connected to the pixels (must support PWM!).
LED_FREQ_HZ    = 800000  # LED signal frequency in hertz (usually 800khz)
LED_DMA        = 10      # DMA channel to use for generating signal (try 10)
LED_BRIGHTNESS = 255     # Set to 0 for darkest and 255 for brightest
LED_INVERT     = False   # True to invert the signal (when using NPN transistor level shift)
LED_CHANNEL    = 0
LED_STRIP      = ws.SK6812_STRIP_RGBW
#LED_STRIP      = ws.SK6812W_STRIP

# Define functions which animate LEDs in various ways.
def wheel(pos):
        """Generate rainbow colors across 0-255 positions."""
        if pos < 85:
                return Color(pos * 3, 255 - pos * 3, 0)
        elif pos < 170:
                pos -= 85
                return Color(255 - pos * 3, 0, pos * 3)
        else:
                pos -= 170
                return Color(0, pos * 3, 255 - pos * 3)

def colorWipe(strip, color, wait_ms=20):
        """Wipe color across display a pixel at a time."""
        for i in range(strip.numPixels()):
                strip.setPixelColor(i, color)
                strip.show()
                time.sleep(wait_ms/1000.0)

def rainbowCycle(strip, wait_ms=20, iterations=5):
        """Draw rainbow that uniformly distributes itself across all pixels."""
        while not stop:
            for j in range(256*iterations):
                    for i in range(strip.numPixels()):
                            strip.setPixelColor(i, wheel(((i * 256 // strip.numPixels()) + j) & 255))
                    strip.show()
                    time.sleep(wait_ms/1000.0)

class RainbowLights(Thread):
    def __init__(self, name="RainbowLights"):
        self._stopevent = EV()
        self.sleeppreiod = 1.0

        Thread.__init__(self, name=name)

    def run(self):
        while not self._stopevent.isSet():
            rainbowCycle(strip)
            self._stopevent.wait(self._sleepperiod)


if __name__ == '__main__':
        parser = argparse.ArgumentParser()
        parser.add_argument('-c', '--clear', action='store_true', help='clear the display on exit')
        args = parser.parse_args()

        # Create NeoPixel object with appropriate configuration.
        strip = Adafruit_NeoPixel(LED_COUNT, LED_PIN, LED_FREQ_HZ, LED_DMA, LED_INVERT, LED_BRIGHTNESS, LED_CHANNEL, LED_STRIP)
        # Intialize the library (must be called once before other functions).
        strip.begin()

        print ('Press Ctrl-C to quit.')
        if not args.clear:
                print('Use "-c" argument to clear LEDs on exit')

        GPIO.setup(22, GPIO.IN) #PIR

        rta = "none"
        time1 = "none"
        stop = False
        RainbowLights = RainbowLights()

        try:
            time.sleep(2) # to stabilize sensor
            while True:
                trigger = GPIO.input(22)
                if trigger == 1:
                    print("Motion Detected...")
                    if rta == "running":
                        print("Lights Already On")
                    else:
                        RainbowLights.start()
                        rta = "running"
                        time1 = dt.datetime.now()
                    time.sleep(5) #to avoid multiple detection
                elif trigger == 0:
                    print("No Motion...")
                    print("Lights turned on at " + str(time1))
                time.sleep(0.1) #loop delay, should be less than detection delay

        except KeyboardInterrupt:
                 RainbowLights._stopevent.set()
                 stop = True
                 time.sleep(5)
                 if args.clear:
                     colorWipe(strip, Color(0,0,0), 10)
                 GPIO.cleanup()

标签： pythonmultithreadingrgb

解决方案

简化为一个最小的示例，因此它可以在没有硬件的情况下运行。为修复添加了评论。主要问题是stop仅在256*iterations*wait_ms/1000.025.6 秒后检查，因此停止似乎没有响应。还有一些其他的错误。Globalstop足以结束线程，因此Event不需要。

import time
import argparse
from threading import Thread
import sys

global stop

def rainbowCycle(strip, wait_ms=20, iterations=5):
    """Draw rainbow that uniformly distributes itself across all pixels."""
    while not stop:
        for j in range(256*iterations):
            if stop: break                # add stop check here for responsiveness.
            print(f'rainbowCycle')
            time.sleep(wait_ms/1000.0)
    print('stopping...')

class RainbowLights(Thread):
    def __init__(self, name="RainbowLights"):
        print('__init__')
        Thread.__init__(self, name=name)

    def run(self):
        print('run')
        rainbowCycle(strip)
        print('stopped')

if __name__ == '__main__':
    strip = None
    print('Press Ctrl-C to quit.')
    rta = "none"
    stop = False
    rainbow_lights = RainbowLights()   # renamed variable so it doesn't replace the class.

    try:
        time.sleep(2) # to stabilize sensor
        while True:
            trigger = 1      # pretend some motion
            if trigger == 1:
                print("Motion Detected...")
                if rta == "running":
                    print("Lights Already On")
                else:
                    rainbow_lights.start()
                    rta = "running"
                time.sleep(5) #to avoid multiple detection
            elif trigger == 0:
                print("No Motion...")
            time.sleep(0.1) #loop delay, should be less than detection delay

    except KeyboardInterrupt:
        print('KeyboardInterrupt')
        print('stop')
        stop = True

Press Ctrl-C to quit.
__init__
Motion Detected...
run
rainbowCycle
rainbowCycle
rainbowCycle
rainbowCycle
rainbowCycle
rainbowCycle
rainbowCycle
rainbowCycle
rainbowCycle
rainbowCycle
rainbowCycle
rainbowCycle
KeyboardInterrupt
stop
stopping...
stopped

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