import tarfile
from concurrent.futures.thread import ThreadPoolExecutor
from io import BytesIO

def test_lzma(x):
    buf = BytesIO()
    with tarfile.open(fileobj=buf, mode="w") as archive:
        tarinfo = tarfile.TarInfo(name="x")
        tarinfo.size = 1
        archive.addfile(tarinfo=tarinfo, fileobj=BytesIO(b"x"))
    buf.seek(0)
    tarfile.open(fileobj=buf, mode="r")
    print("SUCCESS", x)

with ThreadPoolExecutor(max_workers=5) as pool:
    list(pool.map(test_lzma, range(100)))