Hi,
Does anyone now how to free up the memory in a XMLElement object in
LightXML.jl?
LightXML.jl has a free(xdoc::XMLDocument) but no corresponding
free(xelem::XMLElement). There are functions related to free in clib.jl in
the package but no docs that I can find on how to use it. I tried to create
an XMLDocument from the element and then free the document but mem still
leaks. Help appreciated.
Background/context/details:
In another thread we found out that our problems with mem-leaks in a
long-running optimization is probably due to the use of LightXML.jl. The
latter seem to require manual free'ing of resources as of the current
version. Basically our main loop is something like this:
# Create a large number of XMLElement's (possibly deeply nested) with
construct_element(name::String, content::Array{Any}) = begin
xmlelement = new_element(name)
for item in content
if typeof(item) <: Main.XMLElement
add_child(xmlelement, item)
elseif typeof(item) <: (String,String)
set_attribute(xmlelement, item[1], item[2])
elseif typeof(item) <: String
add_text(xmlelement, item)
else
@assert false
end
end
xmlelement
end
# What we are optimizing is the length of the xml when printed as string so
we evaluated this by looping over array of xml elements generated
# by construct_element above and calling on each one (the replace is for
taking away at least some of the whitespace which is not important):
fitness(xml) = length(replace(string(xml), r">\s+<", "><"))
Since the optimization algorithm calls fitness on 100K to several million
xml elements per run when we compare several optimization algorithms to
each other the mem expansion gets up to many gigs and eventually there is
problems. It seems there is no free on XMLElement in LightXML.jl but there
is a free for XMLDocument. We thus tried to change to this:
free_xmlelement(xmlelem::XMLElement) = begin
tempdoc = XMLDocument()
set_root(tempdoc, xmlelem)
free(tempdoc)
end
fitness_with_free(xml) = begin
qv = length(replace(string(xml), r">\s+<", "><"))
free_xmlelement(xml)
qv
end
but it does not seem to help. We would appreciate any help/advice on this
or how we can further debug it. The documentation for xmlFreeDoc in libxml2
(which is what is what LightXML.free(xdoc::XMLDocument) calls) says that
it will recursively free the document. But maybe we are missing something.
Thanks for any advice,
Robert Feldt
