<div dir="ltr">As a small follow-up, the same exact CPU spinning problem (and the presumably related QObject::killTimer message) also happen when run on Windows with python 3.5.2 (Anaconda 4.1.1 64-bit) with the PyQt 5.7.0 wheel.<div><br></div></div><div class="gmail_extra"><br><div class="gmail_quote">On Sat, Nov 19, 2016 at 7:32 PM, Russell Warren <span dir="ltr"><<a href="mailto:russ@perspexis.com" target="_blank">russ@perspexis.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><p dir="ltr">Sorry... This is on 64 bit Linux with the latest version from pypi at this moment.</p><div class="HOEnZb"><div class="h5">
<div class="gmail_extra"><br><div class="gmail_quote">On Nov 19, 2016 6:31 PM, "Russell Warren" <<a href="mailto:russ@perspexis.com" target="_blank">russ@perspexis.com</a>> wrote:<br type="attribution"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><div>I'm having a CPU-spinning problem, together with an odd QObject::killTimer error, with a basic use case of QQuickPaintedItem.</div><div><br></div><div>I've reduced the example down so that the meat of it is just this:</div><div><br></div><div>1. Create a QGraphicsScene with some QGraphicsItems in it</div><div>2. Create a QQuickPaintedItem to render the scene to QML</div><div>3. Call QGraphicsScene.render(painter) inside the .paint of QQuickPaintedItem</div><div><br></div><div>When I do this, it superficially works as I want, but I get an error to stdout, and the CPU spins to 100%. Using strace it can be seen that the CPU is spinning on a poll(), like seen in this capture:</div><div><br></div><div><a href="https://i.snag.gy/I6QZvH.jpg" target="_blank">https://i.snag.gy/I6QZvH.jpg</a></div><div><br></div><div>The FDs being polled are a socket and an 'anon_inode:[eventfd]', which is (I think) the normal Qt event loop.</div><div><br></div><div>The error that results is this:</div><div><br></div><div> $ python HeatMapProblem.py</div><div> QObject::killTimer: Timers cannot be stopped from another thread</div><div><br></div><div>This timer problem is probably related, because the spinning is likely what would happen with a zero timeout timer.</div><div><br></div><div>Everything *seems* like it is being done correctly from the Qt side of things. Is there something wrong I'm doing with PyQt?</div><div><br></div><div>Basic code below (two files... heatmap.qml and HeatMapProblem.py).</div><div><br></div><div>Thanks,</div><div>Russ</div><div><br></div><div><font face="monospace, monospace">#####</font></div><div><font face="monospace, monospace">### heatmap.qml</font></div><div><font face="monospace, monospace">#####</font></div><div><font face="monospace, monospace"><br></font></div><div><font face="monospace, monospace">import QtQuick 2.0</font></div><div><font face="monospace, monospace">import QtQuick.Window 2.2</font></div><div><font face="monospace, monospace">import Heatmap 1.0</font></div><div><font face="monospace, monospace"><br></font></div><div><font face="monospace, monospace">Window {</font></div><div><font face="monospace, monospace"> visible: true</font></div><div><font face="monospace, monospace"> width: 500</font></div><div><font face="monospace, monospace"> height: 500</font></div><div><font face="monospace, monospace"> MyHeatmap {</font></div><div><font face="monospace, monospace"> anchors.fill: parent</font></div><div><font face="monospace, monospace"> }</font></div><div><font face="monospace, monospace">}</font></div><div><font face="monospace, monospace"><br></font></div><div><font face="monospace, monospace">#####</font></div><div><font face="monospace, monospace">### HeatMapProblem.py</font></div><div><font face="monospace, monospace">#####</font></div><div><font face="monospace, monospace">#!/usr/bin/env python</font></div><div><font face="monospace, monospace">import random</font></div><div><font face="monospace, monospace"><br></font></div><div><font face="monospace, monospace">from OpenGL import GL # workaround for Nvidia issue on linux (see <a href="http://goo.gl/pGPgVz" target="_blank">http://goo.gl/pGPgVz</a>)</font></div><div><font face="monospace, monospace">import PyQt5.QtWidgets as QtWidgets</font></div><div><font face="monospace, monospace">from PyQt5.QtQuick import QQuickItem, QQuickPaintedItem, QQuickView</font></div><div><font face="monospace, monospace">import PyQt5.QtCore as QtCore</font></div><div><font face="monospace, monospace">import PyQt5.QtGui as QtGui</font></div><div><font face="monospace, monospace">import PyQt5.QtQml as QtQml</font></div><div><font face="monospace, monospace"><br></font></div><div><font face="monospace, monospace">class MyPolygon(QtWidgets.QGraphicsP<wbr>olygonItem):</font></div><div><font face="monospace, monospace"> def __init__(self, PolyPoints, parent = None):</font></div><div><font face="monospace, monospace"> super(MyPolygon, self).__init__(PolyPoints, parent)</font></div><div><font face="monospace, monospace"> color = QtGui.QColor(*(random.randint(<wbr>0, 128) for x in range(3)))</font></div><div><font face="monospace, monospace"> self.setBrush(QtGui.QBrush(col<wbr>or))</font></div><div><font face="monospace, monospace"> </font></div><div><font face="monospace, monospace">class MyScene(QtWidgets.QGraphicsSce<wbr>ne):</font></div><div><font face="monospace, monospace"> def __init__(self, parent=None):</font></div><div><font face="monospace, monospace"> super(MyScene, self).__init__(parent)</font></div><div><font face="monospace, monospace"> blackPen = QtGui.QPen(QtCore.Qt.black, 1)</font></div><div><font face="monospace, monospace"> blackPen.setCosmetic(True)</font></div><div><font face="monospace, monospace"> </font></div><div><font face="monospace, monospace"> numWide = numHigh = 3</font></div><div><font face="monospace, monospace"> boxes = []</font></div><div><font face="monospace, monospace"> for x in range(numWide):</font></div><div><font face="monospace, monospace"> for y in range(numHigh):</font></div><div><font face="monospace, monospace"> bl = (x*10, y*10)</font></div><div><font face="monospace, monospace"> tl = (x*10 , y*10 + 10)</font></div><div><font face="monospace, monospace"> tr = (x*10 + 10, y*10 + 10)</font></div><div><font face="monospace, monospace"> br = (x*10 + 10, y*10)</font></div><div><font face="monospace, monospace"> polyDef = [bl, tl, tr, br, bl]</font></div><div><font face="monospace, monospace"> poly = QtGui.QPolygonF([QtCore.QPoint<wbr>F(x, y) for (x, y) in polyDef])</font></div><div><font face="monospace, monospace"> item = MyPolygon(poly, parent = None)</font></div><div><font face="monospace, monospace"> item.setPen(blackPen) #polygon border</font></div><div><font face="monospace, monospace"> self.addItem(item)</font></div><div><font face="monospace, monospace"><br></font></div><div><font face="monospace, monospace">class MyQMLScene(QQuickPaintedItem):</font></div><div><font face="monospace, monospace"> def __init__(self, parent = None):</font></div><div><font face="monospace, monospace"> super(MyQMLScene, self).__init__(parent)</font></div><div><font face="monospace, monospace"> self._Scene = MyScene(parent = self)</font></div><div><font face="monospace, monospace"> </font></div><div><font face="monospace, monospace"> def paint(self, painter):</font></div><div><font face="monospace, monospace"> self._Scene.render(painter) # NOTE: comment this out and no problems exist!</font></div><div><font face="monospace, monospace"> pass</font></div><div><font face="monospace, monospace"><br></font></div><div><font face="monospace, monospace">if __name__ == '__main__':</font></div><div><font face="monospace, monospace"> import sys</font></div><div><font face="monospace, monospace"> app = QtWidgets.QApplication(sys.arg<wbr>v)</font></div><div><font face="monospace, monospace"> QtQml.qmlRegisterType(MyQMLSce<wbr>ne, "Heatmap", 1, 0, "MyHeatmap")</font></div><div><font face="monospace, monospace"> engine = QtQml.QQmlApplicationEngine()</font></div><div><font face="monospace, monospace"> engine.load("heatmap.qml")</font></div><div><font face="monospace, monospace"> sys.exit(app.exec_())</font></div><div><font face="monospace, monospace"><br></font></div><div><br></div><div><br></div>
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</div></div></blockquote></div><br><br clear="all"><div><br></div>-- <br><div class="gmail_signature" data-smartmail="gmail_signature"><div dir="ltr"><div><font color="#000099">Russell Warren</font></div><div><font color="#000099">Perspexis Technologies Inc.</font></div><div><font color="#000099"><br></font></div><div><font color="#000099">This information is confidential and intended solely for the use of the individual or entity to whom it is addressed.</font></div><div><span style="color:rgb(0,0,153)">If you have received this email in error, please notify the sender immediately.</span></div></div></div>
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