On Fri, 26 Feb 2021 08:19:14 +0100 Christian Gollwitzer <aurio...@gmx.de> wrote:
> Am 26.02.21 um 06:15 schrieb John O'Hagan: [...] > > > > I've followed your suggestions as per my last post, and can confirm > > the same freezing behaviour when running your code directly as a > > tclsh script on Debian Testing, Tcl 8.6.11. > > You might report this as a bug to the Tcl bugtracker > https://core.tcl-lang.org/tk/ticket > > I guess the problem is with the steady creation of widgets. Tk was > not meant to be used like that. Tkinter creates new widget names for > each widget with random numbers, just like the Tcl code above does, > whereas in a usual Tcl/Tk program the names are given by the > programmer. Thanks, I will make the bug report. However, based on your comments above, it looks similar to this one, closed as invalid 16 years ago: https://core.tcl-lang.org/tk/tktview/1173484fffffffffffff This was also related to memory "creep" caused by Tk's cache of names, which AIUI is a Tk design feature (but I don't know Tk!). > Can you also check this program, which reuses the same widget path > name, albeit does the creation/destruction in cycles: > > ====================== > package require Tk > > proc randint {} { > expr {int(rand()*10000000)} > } > > proc display {label} { > destroy $label > set label [label .l -text [randint]] > pack $label > after 100 [list display $label] > } > > display [label .l] > ======================== > I have tried this overnight and it is still running, not frozen and with no apparent increase in memory use. I guess that is likely the issue. I don't know Tcl/Tk - is there a way to emulate the above approach of re-using the widget name in tkinter? > As mentioned by others, typically you wouldn't continuously recreate > new widgets, but either update the text of the widget > (label['text']="New text") or attaching a StringVar() ) > > or, if you must rearrange the widgets, you pack_forget() them and > then repack them. > > Christian This is possible of course, but will require more than a repack. In my use case, each widget is an attribute of a Python object, intended control and display data about that object, and there is an indeterminate number of such objects at any given time. I had assumed I could just destroy the widget and let the object go out of scope to be garbage collected. I'll need to redesign this altogether if I can't rely on Tk to manage memory. IMHO it's quite surprising if .destroy doesn't free all the resources used by a widget! Thanks -- John -- https://mail.python.org/mailman/listinfo/python-list
