Runtime: work around 1s delay added when using twisted reactor's callLater.
Since wxPython4, using wxReactor from non-main thread was producing
exceptions in wxWidget's C++ code. Then reactor.run() was called from
main thread, and runtime's worker was delegating calls to reactor
with callLater(0, callable).
While this worked perfectly with wxReactor, it did introduce an unexplained
1 second delay to each worker call when using nomal linux reactors
(i.e. without wxPython). As a workaround reactor runs in a thread when using
twisted without wxPython
<?xml version='1.0' encoding='utf-8'?>
<PyFile xmlns:xhtml="http://www.w3.org/1999/xhtml" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
<variables>
<variable name="SomePLCglobal" type="HMI_STRING" initial="'blaf'" onchange="MyOnChangeFunc"/>
</variables>
<globals>
<xhtml:p><![CDATA[
def MyOnChangeFunc(changed_var_name):
print changed_var_name + ": " + getattr(PLCGlobals, changed_var_name)
]]></xhtml:p>
</globals>
<init>
<xhtml:p><![CDATA[
]]></xhtml:p>
</init>
<cleanup>
<xhtml:p><![CDATA[
]]></xhtml:p>
</cleanup>
<start>
<xhtml:p><![CDATA[
]]></xhtml:p>
</start>
<stop>
<xhtml:p><![CDATA[
]]></xhtml:p>
</stop>
</PyFile>