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Python crashes when closing figures using TkAgg on Mac OS #9856
Description
Bug report
Bug summary
Python crashes when I create and then close figures in a for loop using the TkAgg backend on Mac OS X in an interactive session. The Python session crashes out with
called Tcl_FindHashEntry on deleted table Abort trap: 6
This may be related to #7743 and #8387.
Code for reproduction
import sys
import matplotlib as mpl
import pylab as plt
print('OS: %s'%sys.platform)
print('matplotlib version: %s'%mpl.__version__)
print('Backend: %s'%matplotlib.get_backend())
for i in range(3):
plt.figure()
plt.close()
plt.figure()
plt.plot([0,1],[0,1])
plt.show()Actual outcome
$ python -i figure_close.py OS: darwin matplotlib version: 2.0.2 Backend: TkAgg called Tcl_FindHashEntry on deleted table Abort trap: 6
Expected outcome
I would expect this code to create and destroy three figures before creating and retaining the last figure.
Matplotlib version
- Operating system: Mac OS X 10.12.1
- Matplotlib version: 2.0.2
- Matplotlib backend (print(matplotlib.get_backend())): TkAgg
- Python version: 2.7.13
This was matplotlib installed from conda from the conda-forge channel.
Activity
tacaswell commented on Nov 25, 2017
I get slightly different (and less fatal) errors with masterish on linux:
18:44 $ python /tmp/tk_close.py OS: linux matplotlib version: 2.1.0.post289+g88a20b7e6 Backend: TkAgg can't invoke "event" command: application has been destroyed while executing "event generate $w <<ThemeChanged>>" (procedure "ttk::ThemeChanged" line 6) invoked from within "ttk::ThemeChanged" can't invoke "event" command: application has been destroyed while executing "event generate $w <<ThemeChanged>>" (procedure "ttk::ThemeChanged" line 6) invoked from within "ttk::ThemeChanged" can't invoke "event" command: application has been destroyed while executing "event generate $w <<ThemeChanged>>" (procedure "ttk::ThemeChanged" line 6) invoked from within "ttk::ThemeChanged"My guess is that we are creating an tearing down Tk objects when the figures are created and then destroyed, but are leaving things in a limbo-like state. When we finally let the tk event loop run with show() it dies.
jklymak commented on Dec 2, 2017
I get the same as @tacaswell on master-ish:
OS: darwin matplotlib version: 2.1.0.post954+g1d4160c4b Backend: TkAgg can't invoke "event" command: application has been destroyed while executing "event generate $w <<ThemeChanged>>"This unsightly, but it doesn't "crash" python on macOS. Tempted to close this, but I am going to remove the OS/Apple label because the behaviour is the same in MacOS and linux (at least on master).
tacaswell commented on Dec 3, 2017
We should leave this open, there is a real race condition here. Frequently these sorts of things are responsible for more than one odd behavior (that are hard to reproduce due to the race), having a more-or-less reproducible repro example is helpful!
kadrlica commented on Dec 3, 2017
I have seen similar warnings (i.e. can't invoke "event" command: ...) in other situations with version 2.0.2, but they do not appear for me with this simple working example.
anntzer commented on Dec 3, 2017
Does #9275 help?
mattip commented on Dec 8, 2017
This reproduces in PyPy (with PR #9275 and PR #9356 ) as well.
mattip commented on Dec 8, 2017
Let me know if I am being too noisy, I am diving into this and using this issue as a record of my work.
Adding some print statements, it seems the problem is starting the event loop after closing the images
first the diff:
diff --git a/lib/matplotlib/backends/backend_tkagg.py b/lib/matplotlib/backends/backend_tkagg.py index 7a36dc6..6e23b96 100644 --- a/lib/matplotlib/backends/backend_tkagg.py +++ b/lib/matplotlib/backends/backend_tkagg.py @@ -214,6 +214,10 @@ class FigureCanvasTkAgg(FigureCanvasAgg): self._master = master self._tkcanvas.focus_set() + def close_event(self, *args, **kwargs): + print('in close_event') + FigureCanvasAgg.close_event(self, *args, **kwargs) + def resize(self, event): width, height = event.width, event.height if self._resize_callback is not None: @@ -1079,4 +1083,6 @@ class _BackendTkAgg(_Backend): @staticmethod def mainloop(): + print('starting main loop') Tk.mainloop() + print('stopping main loop')which now prints:
OS: linux2 matplotlib version: 2.1.0+989.g1712678 Backend: TkAgg in close_event in close_event in close_event starting main loop can't invoke "event" command: application has been destroyed while executing "event generate $w <<ThemeChanged>>" (procedure "ttk::ThemeChanged" line 6) invoked from within "ttk::ThemeChanged" can't invoke "event" command: application has been destroyed while executing "event generate $w <<ThemeChanged>>" (procedure "ttk::ThemeChanged" line 6) invoked from within "ttk::ThemeChanged" in close_event stopping main loopNote that the errors are after "starting main loop", in other words only after using pylab.show()
mattip commented on Dec 8, 2017
or perhaps pyplot.close() is not "doing enough" to remove pending events
mattip commented on Dec 8, 2017
PR #9956 fixes the issue for me (linux, PyPy). Could someone on macOS check that it solves the issue for them as well?
tacaswell commented on Dec 13, 2017
@mattip Don't worry about being too noisy!
efiring commented on Dec 13, 2017
Closed by #9956.
I verified this on OSX.