#!/usr/bin/env python
import gc
import unittest
import numpy as np
from tinygrad.tensor import Tensor

def tensors_allocated():
  return sum([isinstance(x, Tensor) for x in gc.get_objects()])

class TestGC(unittest.TestCase):

  def test_gc(self):
    Tensor.manual_seed(0)
    a = Tensor.rand(4, 4, requires_grad=True)
    b = Tensor.zeros(4, 4, requires_grad=True)
    (a*b).mean().backward()
    assert (tensors_allocated() > 0)
    del a,b
    assert (tensors_allocated() == 1) # one for Tensor._device_rng_counters

  def test_gc_complex(self):
    Tensor.manual_seed(0)
    a = Tensor(np.zeros((4, 4), dtype=np.float32), requires_grad=True)
    b = Tensor.rand(4, 4, requires_grad=True)
    assert (tensors_allocated() == 3)
    (a*b).mean().backward()
    assert (tensors_allocated() == 5)
    del b
    assert (tensors_allocated() == 3)
    b = Tensor(np.zeros((4, 4), dtype=np.float32), requires_grad=True)
    print(tensors_allocated())
    (a*b).mean().backward()
    print(tensors_allocated())
    assert (tensors_allocated() == 5)
    del b
    assert (tensors_allocated() == 3)

if __name__ == '__main__':
  unittest.main()
