René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Deleted dotnet object does not get garbage collected","articleBody":"### Environment\r\n\r\n-   Pythonnet version: 3.0.0rc3\r\n-   Python version: 3.10.5\r\n-   Operating System: Windows 10 20H2\r\n-   .NET Runtime: 6.0.6\r\n\r\n### Details\r\n\r\n-   Describe what you were trying to get done.\r\n\r\nCreate dotnet-object and delete it. If I do that a lot I get memory issues. It seems the never get cleared by the Python- or dotnet-gc. This is not a problem in pythonnet 2.5.2\r\n\r\n-   What commands did you run to trigger this issue?\r\n\r\n```python\r\nimport gc\r\nimport clr\r\nimport psutil\r\nimport matplotlib.pyplot as plt\r\nimport System\r\n\r\n# Create dict store count of objects left\r\ntypes = [\r\n    str,\r\n    System.String,\r\n]\r\ntypes = {obj: 0 for obj in types}\r\n\r\nN = 1_000\r\nstr_size = 1_000_000\r\n\r\nmemory_py = [0 for _ in range(N + 2)]\r\nmemory_py[0] = psutil.virtual_memory().used\r\nfor ii in range(N):\r\n    s_py = str('a' * str_size)\r\n    del s_py\r\n    memory_py[ii + 1] = psutil.virtual_memory().used - memory_py[0]\r\n\r\ngc.collect()\r\n# See what types of objects are still present\r\nfor obj in gc.get_objects():\r\n    if type(obj) in list(types.keys()):\r\n        types[type(obj)] += 1\r\nprint(types)\r\nmemory_py[ii + 2] = psutil.virtual_memory().used - memory_py[0]\r\nmemory_py[0] = 0\r\n```\r\n```\r\n{\u003cclass 'str'\u003e: 0, \u003cclass 'System.String'\u003e: 0}\r\n```\r\n```python\r\nmemory_net = [0 for _ in range(N + 2)]\r\nmemory_net[0] = psutil.virtual_memory().used\r\ns_py = str('a' * str_size)\r\nfor ii in range(N):\r\n    s_net = System.String(s_py)\r\n    del s_net\r\n    memory_net[ii + 1] = psutil.virtual_memory().used - memory_net[0]\r\n\r\ngc.collect()\r\n# See what types of objects are still present\r\nfor obj in gc.get_objects():\r\n    if type(obj) in list(types.keys()):\r\n        types[type(obj)] += 1\r\nprint(types)\r\nmemory_net[ii + 2] = psutil.virtual_memory().used - memory_net[0]\r\nmemory_net[0] = 0\r\n```\r\n```\r\n{\u003cclass 'str'\u003e: 0, \u003cclass 'System.String'\u003e: 1000}\r\n```\r\nYou can also visualize the memory consumption:\r\n```python\r\nfig, ax = plt.subplots()\r\nax.plot(memory_py, label='Python object')\r\nax.plot(memory_net, label='DotNet object')\r\nax.legend()\r\nplt.show(fig)\r\n```\r\n![3 0](https://user-images.githubusercontent.com/4509134/178766479-ba480580-a96f-4801-b47a-98bc314a7ec3.png)\r\n\r\nYou can execute the same code with pythonnet 2.5.2 (Python 3.9.13) and get the following figure\r\n\r\n![2 5](https://user-images.githubusercontent.com/4509134/178767059-0e6014ca-8b0f-4fc5-aa48-8c23bc56d13c.png)\r\n\r\n","author":{"url":"https://github.com/m-rossi","@type":"Person","name":"m-rossi"},"datePublished":"2022-07-13T15:12:01.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":7},"url":"https://github.com/1872/pythonnet/issues/1872"}