On 14.05.2018 21:58, Terry Reedy wrote:
On 5/14/2018 12:20 PM, Chris Barker via Python-Dev wrote:
On Wed, May 2, 2018 at 8:21 PM, Terry Reedy <tjre...@udel.edu <mailto:tjre...@udel.edu>> wrote:

    On 5/2/2018 4:38 PM, Ivan Pozdeev via Python-Dev wrote:

        The bottom line is: Tkinter is currently broken


    This is way over-stated.  Many modules have bugs, somethings in
    features more central to their main purpose.

I'll suggest a re-statement:

tkinter is not thread safe,

Still over-stated.  If one uses tcl/tk compiled with thread support, tkinter *is* thread-safe.  This is 'as far as I know' from running posted 'failing' examples (possible with bug fixes) with 3.5+ on Windows, which is installed with tcl/tk 8.6, which defaults to thread-safe.

This means that you didn't (yet) read the letter that I attached to https://bugs.python.org/issue33479 .
Reciting the relevant section:

===
The reality is that with neither flavor of Tcl is Tkinter completely thread-safe, but with threaded flavor, it's more so:

* with nonthreaded Tcl, making concurrent Tcl calls leads to crashes due to incorrect management of the "Tcl lock" as per https://bugs.python.org/issue33257 * with threaded Tcl, the only issue that I found so far is that a few APIs must be called from the interpreter's thread (https://bugs.python.org/issue33412#msg316152; so far, I know `mainloop()` and `destroy()` to be this) -- while most can be called from anywhere. Whether the exceptions are justified is a matter of discussion (e.g. at first glance, `destroy()` can be fixed).
===
Tkinter was intended to also be thread-safe when using tcl/tk without thread support, which was the default for tcl/tk 8.5 and before. The posted examples can fail on 2.x on Windows, which comes with tcl/tk 8.5 or before. _tkinter.c has some different #ifdefs for the two situations.

and yet it is documented as being thread safe

True in https://docs.python.org/3/library/tk.html
Unspecified in https://docs.python.org/3/library/tkinter.html

This is either a bug(s) in the implementation or the docs.

Both

So what are the solutions?

1) fix the docs -- unless tkInter is made thread safe really soon, and fixes are back-ported, this seems like a no brainer -- at least temporarily.

https://bugs.python.org/issue33479 'Document tkinter and threads'

2) fix the issues that make tkInter not thread safe

with non-thread tcl/tk.

https://bugs.python.org/issue33257 has a patch that might improve the situation for one type of call.  Fixing everything might not be possible.  AFAIK, there are currently no tests of thread safety.


--
Regards,
Ivan

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