cpython non-immediate GC

test_gc.py

from threading import Lock
from functools import lru_cache
import shutil
import tempfile

counter = 0
counter_lock = Lock()


class TestFile(object):
    def __init__(self, path, mode="r"):
        self.path = path
        self.fh = open(path, mode)

    def __del__(self):
        global counter_lock, counter
        with counter_lock:
            counter += 1


class TestGC(object):
    def __init__(self, id, file_count, mode="r"):
        self.id = id
        self.open_files = []
        self.indexes = []
        self.dir = tempfile.mkdtemp()
        for i in range(file_count):
            f = self._open(f"{self.dir}/test-file-{id}-{i}", mode)
            self.open_files.append(f)
            self.indexes.append(i)

    @lru_cache()
    def _open(self, path, mode):
        return TestFile(path, mode)

    def __del__(self):
        shutil.rmtree(self.dir)


obj_count = 500
files_per_obj = 100

for i in range(obj_count):
    A = TestGC(str(i), file_count=files_per_obj, mode="w")
del A

print(counter)
assert obj_count * files_per_obj == counter