Clash Royale CLAN TAG#URR8PPP

how do i keep closing a subthread from closing the stdin file descriptor?

I wrote this bit of code to clarify my issue... I keep getting ValueError: I/O operation on closed file.

None of the child threads read from stdin. The loop works great until I start a child thread... can someone tell me how to keep the file descriptor from closing?

import threading
from threadtest2 import Threadtest
import termios, sys, tty
import time

def getchar():
fd = sys.stdin.fileno()
old_settings = termios.tcgetattr(fd)
try:
tty.setraw(sys.stdin.fileno())
ch = sys.stdin.read(1)
finally:
termios.tcsetattr(fd, termios.TCSADRAIN, old_settings)
return ch


tt2 = Threadtest()
stop = threading.Event()

t1 = threading.Thread(target=tt2.thread1, args=[stop, ])
t2 = threading.Thread(target=tt2.thread2, args=[stop, ])

try:
while 1:
while not stop.isSet():
try:
c = getchar()
except IOError: pass
if c == "q":
stop.set()
if c == "x":
stop.set()
exit()
if c == "1":
print "starting t1"
t1.start()
if c == "2":
print "starting t2"
t2.start()
while len(threading.enumerate()) > 1:
print 'waiting for ' + str(len(threading.enumerate()) - 1) + ' threads to closer'
time.sleep(1)
stop.clear()
print "stop has been triggered and reset... restart"
finally:
print "done!"


there have been a few other threads (pardon the pun) that touched on this, but I haven't found one that directly addresses it and have been flailing for a while.

FYI, the child threads just wait for stop to be set and sleep...

1 Answer
1

I made small changes to your code to run it standalone. The following does not generate the error for me on a Linux machine. Do you still see the error with it? If so, I'd be glad to improve the answer - please give a few more details about how you are running the code such the operating system in use.

import threading
import termios, sys, tty
import time

def getchar():
fd = sys.stdin.fileno()
old_settings = termios.tcgetattr(fd)
try:
tty.setraw(sys.stdin.fileno())
ch = sys.stdin.read(1)
finally:
termios.tcsetattr(fd, termios.TCSADRAIN, old_settings)
return ch

class Threadtest:
def thread1(self, stop):
stop.wait()
print "returning from thread1"
def thread2(self, stop):
stop.wait()
print "returning from thread2"

tt2 = Threadtest()
stop = threading.Event()

try:
while 1:
t1 = threading.Thread(target=tt2.thread1, args=[stop, ])
t2 = threading.Thread(target=tt2.thread2, args=[stop, ])

while not stop.isSet():
try:
c = getchar()
except IOError: pass
if c == "q":
stop.set()
if c == "x":
stop.set()
sys.exit()
if c == "1":
print "starting t1"
t1.start()
if c == "2":
print "starting t2"
t2.start()
print "waiting for threads to close".format(threading.active_count() - 1)
for t in [t1, t2]:
t.join()
stop.clear()
print "stop has been triggered and reset... restart"
finally:
print "done!"


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