test_glfw_canvas_del Windows fatal exception: access violation

[Korijn]

I just ran pytest tests and got the following segmentation fault:

tests\test_gui_glfw.py ..Windows fatal exception: access violation

Current thread 0x00005364 (most recent call first):
  File "C:\Users\kvang\dev\wgpu-py\.venv\lib\site-packages\glfw\__init__.py", line 1274 in destroy_window
  File "C:\Users\kvang\dev\wgpu-py\wgpu\gui\glfw.py", line 188 in _on_close
  File "C:\Users\kvang\dev\wgpu-py\wgpu\gui\glfw.py", line 303 in close
  File "C:\Users\kvang\dev\wgpu-py\wgpu\gui\base.py", line 161 in __del__
  File "C:\Users\kvang\AppData\Local\Programs\Python\Python39\lib\asyncio\base_events.py", line 1875 in _run_once
  File "C:\Users\kvang\AppData\Local\Programs\Python\Python39\lib\asyncio\base_events.py", line 596 in run_forever
  File "C:\Users\kvang\AppData\Local\Programs\Python\Python39\lib\asyncio\windows_events.py", line 316 in run_forever
  File "C:\Users\kvang\AppData\Local\Programs\Python\Python39\lib\asyncio\base_events.py", line 629 in run_until_complete
  File "C:\Users\kvang\dev\wgpu-py\tests\test_gui_glfw.py", line 83 in test_glfw_canvas_del
  File "C:\Users\kvang\dev\wgpu-py\.venv\lib\site-packages\_pytest\python.py", line 194 in pytest_pyfunc_call
  File "C:\Users\kvang\dev\wgpu-py\.venv\lib\site-packages\pluggy\_callers.py", line 39 in _multicall
  File "C:\Users\kvang\dev\wgpu-py\.venv\lib\site-packages\pluggy\_manager.py", line 80 in _hookexec
  File "C:\Users\kvang\dev\wgpu-py\.venv\lib\site-packages\pluggy\_hooks.py", line 265 in __call__
  File "C:\Users\kvang\dev\wgpu-py\.venv\lib\site-packages\_pytest\python.py", line 1792 in runtest
  File "C:\Users\kvang\dev\wgpu-py\.venv\lib\site-packages\_pytest\runner.py", line 169 in pytest_runtest_call
  File "C:\Users\kvang\dev\wgpu-py\.venv\lib\site-packages\pluggy\_callers.py", line 39 in _multicall
  File "C:\Users\kvang\dev\wgpu-py\.venv\lib\site-packages\pluggy\_manager.py", line 80 in _hookexec
  File "C:\Users\kvang\dev\wgpu-py\.venv\lib\site-packages\pluggy\_hooks.py", line 265 in __call__
  File "C:\Users\kvang\dev\wgpu-py\.venv\lib\site-packages\_pytest\runner.py", line 262 in <lambda>
  File "C:\Users\kvang\dev\wgpu-py\.venv\lib\site-packages\_pytest\runner.py", line 341 in from_call
  File "C:\Users\kvang\dev\wgpu-py\.venv\lib\site-packages\_pytest\runner.py", line 261 in call_runtest_hook
  File "C:\Users\kvang\dev\wgpu-py\.venv\lib\site-packages\_pytest\runner.py", line 222 in call_and_report
  File "C:\Users\kvang\dev\wgpu-py\.venv\lib\site-packages\_pytest\runner.py", line 133 in runtestprotocol
  File "C:\Users\kvang\dev\wgpu-py\.venv\lib\site-packages\_pytest\runner.py", line 114 in pytest_runtest_protocol
  File "C:\Users\kvang\dev\wgpu-py\.venv\lib\site-packages\pluggy\_callers.py", line 39 in _multicall
  File "C:\Users\kvang\dev\wgpu-py\.venv\lib\site-packages\pluggy\_manager.py", line 80 in _hookexec
  File "C:\Users\kvang\dev\wgpu-py\.venv\lib\site-packages\pluggy\_hooks.py", line 265 in __call__
  File "C:\Users\kvang\dev\wgpu-py\.venv\lib\site-packages\_pytest\main.py", line 350 in pytest_runtestloop
  File "C:\Users\kvang\dev\wgpu-py\.venv\lib\site-packages\pluggy\_callers.py", line 39 in _multicall
  File "C:\Users\kvang\dev\wgpu-py\.venv\lib\site-packages\pluggy\_manager.py", line 80 in _hookexec
  File "C:\Users\kvang\dev\wgpu-py\.venv\lib\site-packages\pluggy\_hooks.py", line 265 in __call__
  File "C:\Users\kvang\dev\wgpu-py\.venv\lib\site-packages\_pytest\main.py", line 325 in _main
  File "C:\Users\kvang\dev\wgpu-py\.venv\lib\site-packages\_pytest\main.py", line 271 in wrap_session
  File "C:\Users\kvang\dev\wgpu-py\.venv\lib\site-packages\_pytest\main.py", line 318 in pytest_cmdline_main
  File "C:\Users\kvang\dev\wgpu-py\.venv\lib\site-packages\pluggy\_callers.py", line 39 in _multicall
  File "C:\Users\kvang\dev\wgpu-py\.venv\lib\site-packages\pluggy\_manager.py", line 80 in _hookexec
  File "C:\Users\kvang\dev\wgpu-py\.venv\lib\site-packages\pluggy\_hooks.py", line 265 in __call__
  File "C:\Users\kvang\dev\wgpu-py\.venv\lib\site-packages\_pytest\config\__init__.py", line 169 in main
  File "C:\Users\kvang\dev\wgpu-py\.venv\lib\site-packages\_pytest\config\__init__.py", line 192 in console_main
  File "C:\Users\kvang\dev\wgpu-py\.venv\Scripts\pytest.exe\__main__.py", line 7 in <module>
  File "C:\Users\kvang\AppData\Local\Programs\Python\Python39\lib\runpy.py", line 87 in _run_code
  File "C:\Users\kvang\AppData\Local\Programs\Python\Python39\lib\runpy.py", line 197 in _run_module_as_main
...                                                                                  [ 28%]

...

=============================================== 120 passed in 8.55s ================================================

Interestingly the test does pass

[almarklein]

Is this reproducible?

[Korijn]

I'll try again tomorrow with the fault handler enabled.

[Korijn]

Is this reproducible?

Yes, consistently on every run.

It does seem to matter in which order the tests run. If I run the whole test suite, or just the test_gui_glfw test module, I get the exception. If I run only the specific test test_glfw_canvas_del, no error.

I'll try again tomorrow with the fault handler enabled.

Using the faulthandler module doesn't add any detail compared to what I already shared above.

---

On the glfw branch (#448) I also get a segfault:

❯ .venv/Scripts/pytest tests -k test_gui_glfw -s
================================================= test session starts =================================================
platform win32 -- Python 3.9.9, pytest-7.4.3, pluggy-1.0.0
rootdir: C:\Users\kvang\dev\wgpu-py
collecting ... _determine_can_use_wgpu_lib() status code: 0
collected 120 items / 115 deselected / 5 selected

tests\test_gui_glfw.py .Windows fatal exception: access violation

Current thread 0x00004de4 (most recent call first):
  File "C:\Users\kvang\dev\wgpu-py\.venv\lib\site-packages\glfw\__init__.py", line 1292 in window_should_close
  File "C:\Users\kvang\dev\wgpu-py\wgpu\gui\glfw.py", line 311 in is_closed
  File "C:\Users\kvang\dev\wgpu-py\tests\test_gui_glfw.py", line 68 in test_glfw_canvas_basics
  File "C:\Users\kvang\dev\wgpu-py\.venv\lib\site-packages\_pytest\python.py", line 194 in pytest_pyfunc_call
  File "C:\Users\kvang\dev\wgpu-py\.venv\lib\site-packages\pluggy\_callers.py", line 39 in _multicall
  File "C:\Users\kvang\dev\wgpu-py\.venv\lib\site-packages\pluggy\_manager.py", line 80 in _hookexec
  File "C:\Users\kvang\dev\wgpu-py\.venv\lib\site-packages\pluggy\_hooks.py", line 265 in __call__
  File "C:\Users\kvang\dev\wgpu-py\.venv\lib\site-packages\_pytest\python.py", line 1792 in runtest
  File "C:\Users\kvang\dev\wgpu-py\.venv\lib\site-packages\_pytest\runner.py", line 169 in pytest_runtest_call
  File "C:\Users\kvang\dev\wgpu-py\.venv\lib\site-packages\pluggy\_callers.py", line 39 in _multicall
  File "C:\Users\kvang\dev\wgpu-py\.venv\lib\site-packages\pluggy\_manager.py", line 80 in _hookexec
  File "C:\Users\kvang\dev\wgpu-py\.venv\lib\site-packages\pluggy\_hooks.py", line 265 in __call__
  File "C:\Users\kvang\dev\wgpu-py\.venv\lib\site-packages\_pytest\runner.py", line 262 in <lambda>
  File "C:\Users\kvang\dev\wgpu-py\.venv\lib\site-packages\_pytest\runner.py", line 341 in from_call
  File "C:\Users\kvang\dev\wgpu-py\.venv\lib\site-packages\_pytest\runner.py", line 261 in call_runtest_hook
  File "C:\Users\kvang\dev\wgpu-py\.venv\lib\site-packages\_pytest\runner.py", line 222 in call_and_report
  File "C:\Users\kvang\dev\wgpu-py\.venv\lib\site-packages\_pytest\runner.py", line 133 in runtestprotocol
  File "C:\Users\kvang\dev\wgpu-py\.venv\lib\site-packages\_pytest\runner.py", line 114 in pytest_runtest_protocol
  File "C:\Users\kvang\dev\wgpu-py\.venv\lib\site-packages\pluggy\_callers.py", line 39 in _multicall
  File "C:\Users\kvang\dev\wgpu-py\.venv\lib\site-packages\pluggy\_manager.py", line 80 in _hookexec
  File "C:\Users\kvang\dev\wgpu-py\.venv\lib\site-packages\pluggy\_hooks.py", line 265 in __call__
  File "C:\Users\kvang\dev\wgpu-py\.venv\lib\site-packages\_pytest\main.py", line 350 in pytest_runtestloop
  File "C:\Users\kvang\dev\wgpu-py\.venv\lib\site-packages\pluggy\_callers.py", line 39 in _multicall
  File "C:\Users\kvang\dev\wgpu-py\.venv\lib\site-packages\pluggy\_manager.py", line 80 in _hookexec
  File "C:\Users\kvang\dev\wgpu-py\.venv\lib\site-packages\pluggy\_hooks.py", line 265 in __call__
  File "C:\Users\kvang\dev\wgpu-py\.venv\lib\site-packages\_pytest\main.py", line 325 in _main
  File "C:\Users\kvang\dev\wgpu-py\.venv\lib\site-packages\_pytest\main.py", line 271 in wrap_session
  File "C:\Users\kvang\dev\wgpu-py\.venv\lib\site-packages\_pytest\main.py", line 318 in pytest_cmdline_main
  File "C:\Users\kvang\dev\wgpu-py\.venv\lib\site-packages\pluggy\_callers.py", line 39 in _multicall
  File "C:\Users\kvang\dev\wgpu-py\.venv\lib\site-packages\pluggy\_manager.py", line 80 in _hookexec
  File "C:\Users\kvang\dev\wgpu-py\.venv\lib\site-packages\pluggy\_hooks.py", line 265 in __call__
  File "C:\Users\kvang\dev\wgpu-py\.venv\lib\site-packages\_pytest\config\__init__.py", line 169 in main
  File "C:\Users\kvang\dev\wgpu-py\.venv\lib\site-packages\_pytest\config\__init__.py", line 192 in console_main
  File "C:\Users\kvang\dev\wgpu-py\.venv\Scripts\pytest.exe\__main__.py", line 7 in <module>
  File "C:\Users\kvang\AppData\Local\Programs\Python\Python39\lib\runpy.py", line 87 in _run_code
  File "C:\Users\kvang\AppData\Local\Programs\Python\Python39\lib\runpy.py", line 197 in _run_module_as_main
F...

====================================================== FAILURES =======================================================
_______________________________________________ test_glfw_canvas_basics _______________________________________________

    def test_glfw_canvas_basics():
        """Create a window and check some of its behavior. No wgpu calls here."""

        import glfw
        from wgpu.gui.glfw import WgpuCanvas

        canvas = WgpuCanvas()

        canvas.set_logical_size(300, 200)
        etime = time.time() + 0.1
        while time.time() < etime:
            glfw.poll_events()
        lsize = canvas.get_logical_size()
        assert isinstance(lsize, tuple) and len(lsize) == 2
        assert isinstance(lsize[0], float) and isinstance(lsize[1], float)
        assert lsize == (300.0, 200.0)

        assert len(canvas.get_physical_size()) == 2
        assert isinstance(canvas.get_pixel_ratio(), float)

        # Close
        assert not canvas.is_closed()
        if sys.platform.startswith("win"):  # On Linux we cant do this multiple times
            canvas.close()
            glfw.poll_events()
>           assert canvas.is_closed()

tests\test_gui_glfw.py:68:
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
wgpu\gui\glfw.py:311: in is_closed
    return glfw.window_should_close(self._window)
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

window = None

    def window_should_close(window):
        """
        Checks the close flag of the specified window.

        Wrapper for:
            int glfwWindowShouldClose(GLFWwindow* window);
        """
>       return _glfw.glfwWindowShouldClose(window)
E       OSError: exception: access violation reading 0x000000000000001C

.venv\lib\site-packages\glfw\__init__.py:1292: OSError
=============================================== short test summary info ===============================================
FAILED tests/test_gui_glfw.py::test_glfw_canvas_basics - OSError: exception: access violation reading 0x000000000000001C
===================================== 1 failed, 4 passed, 115 deselected in 4.66s =====================================

Using version glfw-2.6.3

---

Another observation, I used to get this error when closing a glfw window:

❯ .venv/Scripts/python examples/triangle_glfw.py
C:\Users\kvang\dev\wgpu-py\.venv\lib\site-packages\glfw\__init__.py:916: GLFWError: (65537) b'The GLFW library is not initialized'
  warnings.warn(message, GLFWError)

But on the glfw branch (#448) that is fixed.

[almarklein]

It now crashes at is_closed, where there is indeed an unguarded use of _window. I pushed a new commit to the glfw branch. Can you try again?

[Korijn]

With the last commit of the glfw branch it's fixed 🎉

❯ .venv/Scripts/pytest tests -k test_gui_glfw -s
================================================= test session starts =================================================
platform win32 -- Python 3.9.9, pytest-7.4.3, pluggy-1.0.0
rootdir: C:\Users\kvang\dev\wgpu-py
collecting ... _determine_can_use_wgpu_lib() status code: 0
collected 120 items / 115 deselected / 5 selected

tests\test_gui_glfw.py .....

========================================== 5 passed, 115 deselected in 4.49s ==========================================

[almarklein]

Closed by #448