[ python-Feature Requests-1702036 ] Turtle isn't thread-safe (crashes)

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Feature Requests item #1702036, was opened at 2007-04-17 03:29
Message generated for change (Comment added) made by rhettinger
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>Category: Python Library
>Group: Python 2.6
Status: Open
Resolution: None
Priority: 5
Private: No
Submitted By: lomm (korka)
Assigned to: Nobody/Anonymous (nobody)
Summary: Turtle isn't thread-safe (crashes)

Initial Comment:
These are a few examples of errors during code-reentry in the turtle module:

System tested: Windows XP sp2, Python 2.5

1. turtle.circle fails if the tkinter is closed while drawing.

# Code example:
import turtle
turtle.circle(100)
# close the tkinter window while the circle is drawing
# will give an "invalid command name" exception



2. using multiple inheritance, it's possible to draw more than 1 turtle running around at a time. This works part of the time, but crashes python completely on occasions.

# Code example:
import turtle, random
from threading import Thread

class Ninja(Thread, turtle.Turtle):
	'A ninja is a threaded turtle'
	
	def __init__(self):
		# constructors
		Thread.__init__(self)
		turtle.Turtle.__init__(self)
		
		# where will i go?
		self.Direction = random.randint(-180,180)
	
	def run(self):
		# that way!
		self.left(self.Direction)
		
		# march 'forward'
		for i in range(50):
			self.forward(16*random.random())
			self.left(22 - 45*random.random())




ninjas = []
for i in range(3):
	ninjas.append(Ninja())
	ninjas[-1].start()


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>Comment By: Raymond Hettinger (rhettinger)
Date: 2007-04-19 01:58

Message:
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As Josiah says, the current docs do not make any promises about
thread-safety.  So, this isn't a bug.

That being said, it would be nice to offer a way to have multiple turtles
running around under the control of different threads.

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Comment By: Josiah Carlson (josiahcarlson)
Date: 2007-04-19 00:12

Message:
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Does Turtle claim to be thread safe in the documentation?  Should we
explicitly state that Turtle is not thread safe?  Should we also say,
"don't close the turtle window while it is drawing"?

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