chaco pyside memory leak

[robchambers]

There seems to be a memory leak in Chaco when plots are repeatedly updated (example below).

I'm only getting the leak with the qt backend, and only with pyside (not pyqt).

I'm on windows 7 (64-bit) running EPD 7.2-2 (32-bit).
PySide: 1.1.0-2
Chaco: 4.1.0-1
Pyface: 4.1.0-1

We're doing real-time plotting w/ Chaco, and after a few hundred updates the app can easily exceed 2Gb memory usage and crash. I've tried unsuccessfully to figure out where in Chaco this is happening...

Please advise if I can be of assistance in tracking this down. Am I plotting in a non-standard way--is that why other people aren't running into this?

Cheers,
Rob

import os
os.environ['QT_API'] = 'pyside' #'pyqt'  # Only happens with Pyside

from traits.etsconfig.etsconfig import ETSConfig
ETSConfig.toolkit = 'qt4'  # Doesn't seem to happen w/ WX backend.

import numpy as np

from traits.api import HasTraits, Instance
from traitsui.api import View, VGroup, Item 
from pyface.timer.api import do_after

from enable.api import Component, ComponentEditor
from chaco.api import Plot, ArrayPlotData 

PERIOD_MS = 100
DATA_LENGTH = 1000


class PlotViewer(HasTraits):
    """
    Example class showing a Pyside memory leak that happens whenever
    a chaco plot updates...
    """

    pd = Instance(ArrayPlotData)
    plot = Instance(Plot)

    def __init__(self):
        self.plot = Plot(self.pd)
        self.plot.plot(("x", "y"), type="scatter")

        do_after(PERIOD_MS, self._update_pd) # Start plotting loop.

    def _pd_default(self):
        # A random line
        pd = ArrayPlotData(x = np.arange(DATA_LENGTH),
                           y = np.random.rand(DATA_LENGTH))
        return pd

    def _update_pd(self):
        ''' Change the 'y' data, triggering a plot update, every PERIOD_MS ms. '''
        self.pd.set_data('y', np.random.rand(DATA_LENGTH))

        do_after(PERIOD_MS, self._update_pd) # Continue plotting loop...

    # View #####################################################################
    traits_view=View(
                     VGroup(
                            Item('plot',editor=ComponentEditor()),
                            show_labels=False
                            ),
                     width=500, height=500
                     )


if __name__ == "__main__":
    pv = PlotViewer()
    pv.configure_traits()

[robchambers]

I'd be happy to help try to fix this, but I'm not sure where to look... I imagine that switching from pyqt->pyside introduced an error that's being silently caught somewhere? Or, perhaps the error is in Pyside?

[deepankarsharma]

enthought/enable#42 fixes this issue. Once it is merged you can checkout and use enable. Alternatively if it is urgent you might want to apply the patch yourself to your local version.

[robchambers]

That did it - thanks!