Hi all, I'm working on a (Python) program which, in short, is a threaded TCP socket server which creates a new "tab" in a wx.Notebook widget for every incoming connection it sees. I've run into a strange problem where when I call notebook.AddPage(...), one of three things happens:

  1. A "tab" correctly appears for the new page
  2. No new "tab" appears, even though if I call GetPageCount() on the notebook, it returns the correct value
  3. I receive the following error: "*** glibc detected *** python: double free or corruption (fasttop): 0x000000000164dbe0 ****" followed by a very long backtrace with a cryptic memory map.

Since it would be inconsiderate to post all of my code here, I wrote a little script (based on something I found online) which also exhibits this behavior (although it works correctly most of the time).

import wx
from wx.lib.pubsub import Publisher
import thread
import time

# Some classes to use for the notebook pages.  Obviously you would
# want to use something more meaningful for your application, these
# are just for illustration.

class PageOne(wx.Panel):
    def __init__(self, parent):
        wx.Panel.__init__(self, parent)
        t = wx.StaticText(self, -1, "This is a PageOne object", (20,20))

class PageTwo(wx.Panel):
    def __init__(self, parent):
        wx.Panel.__init__(self, parent)
        t = wx.StaticText(self, -1, "This is a PageTwo object", (40,40))

class PageThree(wx.Panel):
    def __init__(self, parent):
        wx.Panel.__init__(self, parent)
        t = wx.StaticText(self, -1, "This is a PageThree object", (60,60))

class MainFrame(wx.Frame):
    def __init__(self):
        wx.Frame.__init__(self, None, title="Simple Notebook Example", size=(600, 500))
        Publisher.subscribe(self.NewPage, "add.page")

        # Here we create a panel and a notebook on the panel
        panel = wx.Panel(self)
        self.notebook = wx.Notebook(panel)

        # create the page windows as children of the notebook
        page1 = PageOne(self.notebook)
        page2 = PageTwo(self.notebook)
        page3 = PageThree(self.notebook)

        # add the pages to the notebook with the label to show on the tab
        self.notebook.AddPage(page1, "Main")

        # finally, put the notebook in a sizer for the panel to manage
        # the layout
        sizer = wx.BoxSizer()
        sizer.Add(self.notebook, 1, wx.EXPAND)

    def NewPage(self, msg):
        name = msg.data
        page = PageOne(self.notebook)
        self.notebook.AddPage(page, name)
        print "Added page with name: '" + name + "'."

def delayedPageAdd():
    n = 1
    while n < 10:
        Publisher.sendMessage("add.page", ("Page%d" % n))
        n += 1

if __name__ == "__main__":
    app = wx.App()
    thread.start_new_thread(delayedPageAdd, ())

In summary, this code creates a wx.Notebook widget and then spawns off a thread that creates a new tab/page every second and adds it to the notebook.

Thank you so much in advance if anybody has any idea what is going on.

Gribouillis commented: An exemplar of well written post +13

Percect! Thank you so much Gribouillis! The decorator worked perfectly - apparently it was a problem with thread safety.

Thanks again!

Great! A good link to keep :)

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