import faulthandler; faulthandler.enable()

import _testcapi
import threading
import sys

NTHREAD = 4

with open("data.xml", "w") as f:
    f.write("<data />")

code = """
import xml.etree.ElementTree as ETree
ETree.parse("data.xml")
"""

def doIt():
    _testcapi.run_in_subinterp(code)

def func():
    tt=[threading.Thread(target=doIt) for _ in range(NTHREAD)]
    for t in tt:
        t.start()
    for t in tt:
        t.join()

func()