Python 3.6: Why does pickle.dumps(nparray) permanently increase refcount?












1















An np.ndarray, when pickled, increments reference counter from the dumps function, however the ref count is never decremented.



Python 3.6.4 Anaconda
Ubuntu 16.04.5 LTS
numpy 1.16.0



I have already tried converting to a list using numpy.array.tolist() however this method is far too slow.



import numpy as np
import pickle
import sys

a = np.ndarray((10, 10), dtype=np.uint8)
print(sys.getrefcount(a)) # 2
pickle.dumps(a)
print(sys.getrefcount(a)) # 3


I would expect the output to be 2, 2 due to the Py_DECREF that occurs in the pickler dumps function, however it remains.



Output is 2, 3 and I cannot fix it. I am leaking memory like crazy.



Currently digging into _pickle.c.










share|improve this question

























  • frame is just rather bog-standard numpy.ndarray() instance. Can you reproduce this issue without cv2 and just with, say, frame = np.zeros((10, 10), dtype=np.uint8)?

    – Martijn Pieters
    Jan 19 at 16:33











  • Also, what exact version of Python 3.6 is this, and what OS is this on?

    – Martijn Pieters
    Jan 19 at 16:35











  • @MartijnPieters I am on Python 3.6.8 Anaconda ubuntu 16.04.5 LTS. I will try to reproduce with np.zeros. Thanks for the advice! Will comment again with results.

    – Eddie Callahan
    Jan 19 at 16:52













  • @MartijnPieters I was able to reproduce with just np.zeros. Numpy refcount increments without ever decrementing. This even ocurrs with ndarray.dumps()

    – Eddie Callahan
    Jan 19 at 16:56













  • right, so we are getting somewhere a little simpler. Can you update your question? You may want to consider filing a bug report with the numpy project, however.

    – Martijn Pieters
    Jan 19 at 16:59
















1















An np.ndarray, when pickled, increments reference counter from the dumps function, however the ref count is never decremented.



Python 3.6.4 Anaconda
Ubuntu 16.04.5 LTS
numpy 1.16.0



I have already tried converting to a list using numpy.array.tolist() however this method is far too slow.



import numpy as np
import pickle
import sys

a = np.ndarray((10, 10), dtype=np.uint8)
print(sys.getrefcount(a)) # 2
pickle.dumps(a)
print(sys.getrefcount(a)) # 3


I would expect the output to be 2, 2 due to the Py_DECREF that occurs in the pickler dumps function, however it remains.



Output is 2, 3 and I cannot fix it. I am leaking memory like crazy.



Currently digging into _pickle.c.










share|improve this question

























  • frame is just rather bog-standard numpy.ndarray() instance. Can you reproduce this issue without cv2 and just with, say, frame = np.zeros((10, 10), dtype=np.uint8)?

    – Martijn Pieters
    Jan 19 at 16:33











  • Also, what exact version of Python 3.6 is this, and what OS is this on?

    – Martijn Pieters
    Jan 19 at 16:35











  • @MartijnPieters I am on Python 3.6.8 Anaconda ubuntu 16.04.5 LTS. I will try to reproduce with np.zeros. Thanks for the advice! Will comment again with results.

    – Eddie Callahan
    Jan 19 at 16:52













  • @MartijnPieters I was able to reproduce with just np.zeros. Numpy refcount increments without ever decrementing. This even ocurrs with ndarray.dumps()

    – Eddie Callahan
    Jan 19 at 16:56













  • right, so we are getting somewhere a little simpler. Can you update your question? You may want to consider filing a bug report with the numpy project, however.

    – Martijn Pieters
    Jan 19 at 16:59














1












1








1








An np.ndarray, when pickled, increments reference counter from the dumps function, however the ref count is never decremented.



Python 3.6.4 Anaconda
Ubuntu 16.04.5 LTS
numpy 1.16.0



I have already tried converting to a list using numpy.array.tolist() however this method is far too slow.



import numpy as np
import pickle
import sys

a = np.ndarray((10, 10), dtype=np.uint8)
print(sys.getrefcount(a)) # 2
pickle.dumps(a)
print(sys.getrefcount(a)) # 3


I would expect the output to be 2, 2 due to the Py_DECREF that occurs in the pickler dumps function, however it remains.



Output is 2, 3 and I cannot fix it. I am leaking memory like crazy.



Currently digging into _pickle.c.










share|improve this question
















An np.ndarray, when pickled, increments reference counter from the dumps function, however the ref count is never decremented.



Python 3.6.4 Anaconda
Ubuntu 16.04.5 LTS
numpy 1.16.0



I have already tried converting to a list using numpy.array.tolist() however this method is far too slow.



import numpy as np
import pickle
import sys

a = np.ndarray((10, 10), dtype=np.uint8)
print(sys.getrefcount(a)) # 2
pickle.dumps(a)
print(sys.getrefcount(a)) # 3


I would expect the output to be 2, 2 due to the Py_DECREF that occurs in the pickler dumps function, however it remains.



Output is 2, 3 and I cannot fix it. I am leaking memory like crazy.



Currently digging into _pickle.c.







python numpy automatic-ref-counting






share|improve this question















share|improve this question













share|improve this question




share|improve this question








edited Jan 19 at 17:06







Eddie Callahan

















asked Jan 19 at 16:07









Eddie CallahanEddie Callahan

104




104













  • frame is just rather bog-standard numpy.ndarray() instance. Can you reproduce this issue without cv2 and just with, say, frame = np.zeros((10, 10), dtype=np.uint8)?

    – Martijn Pieters
    Jan 19 at 16:33











  • Also, what exact version of Python 3.6 is this, and what OS is this on?

    – Martijn Pieters
    Jan 19 at 16:35











  • @MartijnPieters I am on Python 3.6.8 Anaconda ubuntu 16.04.5 LTS. I will try to reproduce with np.zeros. Thanks for the advice! Will comment again with results.

    – Eddie Callahan
    Jan 19 at 16:52













  • @MartijnPieters I was able to reproduce with just np.zeros. Numpy refcount increments without ever decrementing. This even ocurrs with ndarray.dumps()

    – Eddie Callahan
    Jan 19 at 16:56













  • right, so we are getting somewhere a little simpler. Can you update your question? You may want to consider filing a bug report with the numpy project, however.

    – Martijn Pieters
    Jan 19 at 16:59



















  • frame is just rather bog-standard numpy.ndarray() instance. Can you reproduce this issue without cv2 and just with, say, frame = np.zeros((10, 10), dtype=np.uint8)?

    – Martijn Pieters
    Jan 19 at 16:33











  • Also, what exact version of Python 3.6 is this, and what OS is this on?

    – Martijn Pieters
    Jan 19 at 16:35











  • @MartijnPieters I am on Python 3.6.8 Anaconda ubuntu 16.04.5 LTS. I will try to reproduce with np.zeros. Thanks for the advice! Will comment again with results.

    – Eddie Callahan
    Jan 19 at 16:52













  • @MartijnPieters I was able to reproduce with just np.zeros. Numpy refcount increments without ever decrementing. This even ocurrs with ndarray.dumps()

    – Eddie Callahan
    Jan 19 at 16:56













  • right, so we are getting somewhere a little simpler. Can you update your question? You may want to consider filing a bug report with the numpy project, however.

    – Martijn Pieters
    Jan 19 at 16:59

















frame is just rather bog-standard numpy.ndarray() instance. Can you reproduce this issue without cv2 and just with, say, frame = np.zeros((10, 10), dtype=np.uint8)?

– Martijn Pieters
Jan 19 at 16:33





frame is just rather bog-standard numpy.ndarray() instance. Can you reproduce this issue without cv2 and just with, say, frame = np.zeros((10, 10), dtype=np.uint8)?

– Martijn Pieters
Jan 19 at 16:33













Also, what exact version of Python 3.6 is this, and what OS is this on?

– Martijn Pieters
Jan 19 at 16:35





Also, what exact version of Python 3.6 is this, and what OS is this on?

– Martijn Pieters
Jan 19 at 16:35













@MartijnPieters I am on Python 3.6.8 Anaconda ubuntu 16.04.5 LTS. I will try to reproduce with np.zeros. Thanks for the advice! Will comment again with results.

– Eddie Callahan
Jan 19 at 16:52







@MartijnPieters I am on Python 3.6.8 Anaconda ubuntu 16.04.5 LTS. I will try to reproduce with np.zeros. Thanks for the advice! Will comment again with results.

– Eddie Callahan
Jan 19 at 16:52















@MartijnPieters I was able to reproduce with just np.zeros. Numpy refcount increments without ever decrementing. This even ocurrs with ndarray.dumps()

– Eddie Callahan
Jan 19 at 16:56







@MartijnPieters I was able to reproduce with just np.zeros. Numpy refcount increments without ever decrementing. This even ocurrs with ndarray.dumps()

– Eddie Callahan
Jan 19 at 16:56















right, so we are getting somewhere a little simpler. Can you update your question? You may want to consider filing a bug report with the numpy project, however.

– Martijn Pieters
Jan 19 at 16:59





right, so we are getting somewhere a little simpler. Can you update your question? You may want to consider filing a bug report with the numpy project, however.

– Martijn Pieters
Jan 19 at 16:59












1 Answer
1






active

oldest

votes


















0














You've run into this specific bug, and it's a regression in Numpy 1.16.0 only. New code to add support for a new pickle protocol 5 was leaking references to a bound __reduce__ method in the fallback case.



You can either wait for that bug to be fixed and 1.16.1 to be released, or go back to Numpy 1.15.4.






share|improve this answer


























  • Thanks so much!

    – Eddie Callahan
    Jan 19 at 17:11











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1 Answer
1






active

oldest

votes








1 Answer
1






active

oldest

votes









active

oldest

votes






active

oldest

votes









0














You've run into this specific bug, and it's a regression in Numpy 1.16.0 only. New code to add support for a new pickle protocol 5 was leaking references to a bound __reduce__ method in the fallback case.



You can either wait for that bug to be fixed and 1.16.1 to be released, or go back to Numpy 1.15.4.






share|improve this answer


























  • Thanks so much!

    – Eddie Callahan
    Jan 19 at 17:11
















0














You've run into this specific bug, and it's a regression in Numpy 1.16.0 only. New code to add support for a new pickle protocol 5 was leaking references to a bound __reduce__ method in the fallback case.



You can either wait for that bug to be fixed and 1.16.1 to be released, or go back to Numpy 1.15.4.






share|improve this answer


























  • Thanks so much!

    – Eddie Callahan
    Jan 19 at 17:11














0












0








0







You've run into this specific bug, and it's a regression in Numpy 1.16.0 only. New code to add support for a new pickle protocol 5 was leaking references to a bound __reduce__ method in the fallback case.



You can either wait for that bug to be fixed and 1.16.1 to be released, or go back to Numpy 1.15.4.






share|improve this answer















You've run into this specific bug, and it's a regression in Numpy 1.16.0 only. New code to add support for a new pickle protocol 5 was leaking references to a bound __reduce__ method in the fallback case.



You can either wait for that bug to be fixed and 1.16.1 to be released, or go back to Numpy 1.15.4.







share|improve this answer














share|improve this answer



share|improve this answer








edited Jan 19 at 23:18

























answered Jan 19 at 17:08









Martijn PietersMartijn Pieters

709k13624752297




709k13624752297













  • Thanks so much!

    – Eddie Callahan
    Jan 19 at 17:11



















  • Thanks so much!

    – Eddie Callahan
    Jan 19 at 17:11

















Thanks so much!

– Eddie Callahan
Jan 19 at 17:11





Thanks so much!

– Eddie Callahan
Jan 19 at 17:11


















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