线程循环在20分钟后崩溃（RPi/GPIO）
我在寻找帮助，希望能让这段代码更好地运行。这个程序在循环运行了一段时间后（大约15到20分钟）就会卡住。有一些用户告诉我，使用time.sleep()来进行同步不是个好主意，我在想这是不是我的问题。请在回复时用我的代码作为例子，因为我对Python还很陌生。越简单越好。
这段代码应该默认播放一个视频循环，当按下一个按钮（RPi/GPIO）时，会播放另一个视频。等这个视频播放完后，它会回到默认的循环视频。正如你所看到的，我在使用OMXPlayer。
#!/usr/bin/python
from time import sleep
import RPi.GPIO as GPIO
import subprocess
import time
import thread
GPIO.setmode (GPIO.BCM)
GPIO.setwarnings (False)
GPIO.setup(4, GPIO.IN) # Button 1
GPIO.setup(9, GPIO.IN) # Button 2
GPIO.setup(10, GPIO.IN) # Button 3
GPIO.setup(11, GPIO.IN) # Button 4
GPIO.setup(17, GPIO.IN) # Button 5
GPIO.setup(22, GPIO.IN) # Button 6
GPIO.setup(27, GPIO.IN) # Button 7
video_playing = False # Loop flag initial status
def welcome_loop():
global playProcess
while True:
x = 1
if not video_playing:
print "Play Welcome Video"
time.sleep(.05)
playProcess=subprocess.Popen(['omxplayer','-b','Desktop/videos/loop/loop.mp4'],
stdin=subprocess.PIPE,stdout=subprocess.PIPE,
stderr=subprocess.PIPE,close_fds=True)
time.sleep(24) # Length of video
x += 1
def videos():
#initialise a previous input variable to 0 (assume button not pressed last)
prev_input = 0
global video_playing
while True:
button1 = GPIO.input(27)
if ((not prev_input) and button1):
video_playing = True # Set the flag (loop pauses)
print "Stop Welcome Video"
time.sleep(.5)
playProcess.stdin.write('q') # Stop video
time.sleep(.5)
print "Play Martin Lab - Reel"
martinlab_reel=subprocess.Popen(['omxplayer','-b','Desktop/videos/martinlab_reel.mp4'],
stdin=subprocess.PIPE,stdout=subprocess.PIPE,
stderr=subprocess.PIPE,close_fds=True)
time.sleep(30) # Length of video
martinlab_reel.stdin.write('q')
video_playing = False # Unset the flag (loop continues)
#update previous input
prev_input = button1
#slight pause to debounce
time.sleep(.25)
button2 = GPIO.input(9)
if ((not prev_input) and button2):
video_playing = True # Set the flag (loop pauses)
print "Stop Welcome Video"
time.sleep(.5)
playProcess.stdin.write('q') # Stop video
time.sleep(.5)
print "Play Shoppingcart"
shoppingcart=subprocess.Popen(['omxplayer','-b','Desktop/videos/shoppingcart.mp4'],
stdin=subprocess.PIPE,stdout=subprocess.PIPE,
stderr=subprocess.PIPE,close_fds=True)
time.sleep(111) # Length of video
shoppingcart.stdin.write('q')
video_playing = False # Unset the flag (loop continues)
#update previous input
prev_input = button2
#slight pause to debounce
time.sleep(.25)
button3 = GPIO.input(10)
if ((not prev_input) and button3):
video_playing = True # Set the flag (loop pauses)
print "Stop Welcome Video"
time.sleep(.5)
playProcess.stdin.write('q') # Stop video
time.sleep(.5)
print "Play Dodgeballs"
dodgeballs=subprocess.Popen(['omxplayer','-b','Desktop/videos/dodgeballs.mp4'],
stdin=subprocess.PIPE,stdout=subprocess.PIPE,
stderr=subprocess.PIPE,close_fds=True)
time.sleep(102) # Length of video
dodgeballs.stdin.write('q')
video_playing = False # Unset the flag (loop continues)
#update previous input
prev_input = button3
#slight pause to debounce
time.sleep(.25)
button4 = GPIO.input(11)
if ((not prev_input) and button4):
video_playing = True # Set the flag (loop pauses)
print "Stop Welcome Video"
time.sleep(.5)
playProcess.stdin.write('q') # Stop video
time.sleep(.5)
print "Play Hidden Camera"
hiddencamera=subprocess.Popen(['omxplayer','-b','Desktop/videos/hiddencamera.mov'],
stdin=subprocess.PIPE,stdout=subprocess.PIPE,
stderr=subprocess.PIPE,close_fds=True)
time.sleep(37) # Length of video
hiddencamera.stdin.write('q') # Stop video
video_playing = False # Unset the flag (loop continues)
#update previous input
prev_input = button4
#slight pause to debounce
time.sleep(.25)
button5 = GPIO.input(17)
if ((not prev_input) and button5):
video_playing = True # Set the flag (loop pauses)
print "Stop Welcome Video"
time.sleep(.5)
playProcess.stdin.write('q') # Stop video
time.sleep(.5)
print "Play Light of Human Kindness"
lohk_reel=subprocess.Popen(['omxplayer','-b','Desktop/videos/LOHK_short.mp4'],
stdin=subprocess.PIPE,stdout=subprocess.PIPE,
stderr=subprocess.PIPE,close_fds=True)
time.sleep(83) # Length of video
lohk_reel.stdin.write('q')
video_playing = False # Unset the flag (loop continues)
#update previous input
prev_input = button5
#slight pause to debounce
time.sleep(.25)
button6 = GPIO.input(22)
if ((not prev_input) and button6):
video_playing = True # Set the flag (loop pauses)
print "Stop Welcome Video"
time.sleep(.5)
playProcess.stdin.write('q') # Stop video
time.sleep(.5)
print "Play RVA Makerfest"
rva_makerfest=subprocess.Popen(['omxplayer','-b','Desktop/videos/rva_makerfest.mp4'],
stdin=subprocess.PIPE,stdout=subprocess.PIPE,
stderr=subprocess.PIPE,close_fds=True)
time.sleep(101) # Length of video
rva_makerfest.stdin.write('q')
video_playing = False # Unset the flag (loop continues)
#update previous input
prev_input = button6
#slight pause to debounce
time.sleep(.25)
button7 = GPIO.input(27)
if ((not prev_input) and button7):
video_playing = True # Set the flag (loop pauses)
print "Stop Welcome Video"
time.sleep(.5)
playProcess.stdin.write('q') # Stop video
time.sleep(.5)
print "Play PartyBot - Reel"
partybot_reel=subprocess.Popen(['omxplayer','-b','Desktop/videos/partybot_reel.mov'],
stdin=subprocess.PIPE,stdout=subprocess.PIPE,
stderr=subprocess.PIPE,close_fds=True)
time.sleep(61) # Length of video
partybot_reel.stdin.write('q')
video_playing = False # Unset the flag (loop continues)
#update previous input
prev_input = button7
#slight pause to debounce
time.sleep(.25)
thread.start_new_thread( videos, () ) # Videos thread
thread.start_new_thread( welcome_loop, () ) # Loop thread
while True:
pass
GPIO.cleanup() #Reset GPIOs
错误信息（运行2小时后）：
Unhandled exception in thread started by <function welcome_loop at 0xb6c8b3b0>
Traceback (most recent call last):
File "./labmural2.py", line 32, in welcome_loop
stderr=subprocess.PIPE,close_fds=True)
File "/usr/lib/python2.7/subprocess.py", line 679, in __init__
errread, errwrite)
File "/usr/lib/python2.7/subprocess.py", line 1153, in _execute_child
self.pid = os.fork()
OSError: [Errno 12] Cannot allocate memory
内存使用情况（HEAPY返回值）：
Partition of a set of 26904 objects. Total size = 1957148 bytes.
Index Count % Size % Cumulative % Kind (class / dict of class)
0 12601 47 786404 40 786404 40 str
1 6274 23 254548 13 1040952 53 tuple
2 1756 7 126432 6 1167384 60 types.CodeType
3 80 0 122944 6 1290328 66 dict of module
4 203 1 108292 6 1398620 71 dict of type
5 1709 6 102540 5 1501160 77 function
6 121 0 98540 5 1599700 82 dict (no owner)
7 203 1 90232 5 1689932 86 type
8 121 0 70316 4 1760248 90 dict of class
9 1054 4 42160 2 1802408 92 __builtin__.wrapper_descriptor
free -m:
total used free shared buffers cached
Mem: 247 159 87 0 7 75
-/+ buffers/cache: 76 170
Swap: 99 8 91
3 个回答
0
我遇到了一个问题，当我在Linux系统中查看打开的文件时，发现随着时间的推移，打开的文件数量在不断增加。所以当打开的文件数量达到“ulimit -n”这个限制时，脚本就停止了。我的解决办法是增加Linux中可以打开的文件数量，我通过下面的链接把这个数量增加到了1,000,000：
https://www.cyberciti.biz/faq/linux-increase-the-maximum-number-of-open-files/
但其实根本的解决办法是避免打开太多文件。（我只是用一个类来读取温度，但我不知道为什么打开的文件数量会随着时间增加）
0
使用线程和队列，而不是直接用线程和全局变量。
0
你可能是因为启动进程和等待它们完成的方式不对，导致内存或可用进程不够用。等你的程序运行了一段时间后，可以用 ps -AF 来查看当前正在运行的进程数量。
想象一下，你要播放的视频本来应该播放10秒，但实际上只播放了9秒。这会导致系统在第一个视频还没结束的时候，就试图重新开始播放。这是因为有 time.sleep() 的调用。最终，你会发现有很多视频播放器同时在运行同一个视频，这样就会耗尽内存或者超出操作系统允许的进程数量。
我建议把播放和等待的方式改成这样：
playProcess=subprocess.Popen(['omxplayer','-b','Desktop/videos/loop/loop.mp4'],
stdin=subprocess.PIPE,stdout=subprocess.PIPE,
stderr=subprocess.PIPE,close_fds=True)
playProcess.wait() # Wait for video to finish playing