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#!/usr/bin/env python
import gc
import threading
from django.contrib.gis.geos import GEOSGeometry

_old_objs = None
_new_objs = None
_first_time = True


def gc_objects():
    gc.collect()
    objs_counts = {}
    for obj in gc.get_objects():
        key = str(type(obj))
        if key in objs_counts:
            objs_counts[key] += 1
        else:
            objs_counts[key] = 1
    return objs_counts


def dump_memory_leaks():
    global _old_objs
    global _new_objs
    global _first_time
    if _first_time:
        _old_objs = gc_objects()
        _first_time = False
    else:
        _new_objs = gc_objects()
        leaked = {}
        for k, v in _new_objs.items():
            old_v = _old_objs.get(k)
            if old_v:
                diff = _new_objs[k] - old_v
                if diff > 0:
                    leaked[str(k)] = diff
            else:
                leaked[str(k)] = v

        print("Leaks: {}".format(leaked))

        _new_objs = None


def use_geos():
    GEOSGeometry('POINT(5 23)')
    # These lines can get rid of the GEOSContextHandle leak
    # from django.contrib.gis.geos.prototypes.io import thread_context as io_thread_context
    # io_thread_context.__dict__.clear()
    dump_memory_leaks()


if __name__ == '__main__':
    for i in range(10):
        t = threading.Thread(target=use_geos)
        t.start()
        t.join()
        # If I do GC here, it will crash with "double free or corruption" at random `i`
        # dump_memory_leaks()