QUERY · ISSUE

MICROPY_PORT_DEINIT_FUNC called after gc_sweep_all

openby amirgonopened 2020-01-03updated 2020-01-07

I'm using MICROPY_PORT_DEINIT_FUNC to release hardware resources upon soft reset.
Unfortunately, it's called only after gc ram is deallocated by gc_sweep_all.
My port uses gc allocated ram, and when MICROPY_PORT_DEINIT_FUNC is called it's too late, gc ram was already deallocated.

https://github.com/micropython/micropython/blob/10709846f38f8f6519dee27694ce583926a00cb9/ports/esp32/main.c#L145-L153

Is there any particular reason gc_sweep_all is called before mp_deinit?
Is it reasonable to move gc_sweep_all after mp_deinit?

CANDIDATE · PULL REQUEST

ports/stm32/main: Add mp_deinit() in main.

closedby dlechopened 2021-06-28updated 2021-07-01

port-stm32

This adds a call to mp_deinit() in the main function of the STM32 port. This enables the use of the MICROPY_PORT_DEINIT_FUNC hook on that port.

This is just something I noticed while looking at the code. I don't have an actual use case at this time, so happy to hold off on this until someone actually needs it.

Assessment

Q Qwen · high

Issue #5487 reports a bug where MICROPY_PORT_DEINIT_FUNC is called after gc_sweep_all, preventing proper cleanup of gc-allocated hardware resources. PR #7468 adds mp_deinit() support to the STM32 port to enable MICROPY_PORT_DEINIT_FUNC, but it does not address the root cause of the initialization order problem (gc_sweep_all being called before mp_deinit). The PR enables the hook on one port but doesn't fix the underlying issue that the hook is called too late. The query asks about moving gc_sweep_all after mp_deinit, which is a different fix than what the PR implements.

Suggested action

Keep both items open. The PR enables the hook on STM32 but doesn't resolve the initialization order bug reported in the issue. The issue should be addressed by modifying the deinitialization sequence in the core or port-specific code to ensure gc_sweep_all is called after mp_deinit.

MICROPY_PORT_DEINIT_FUNC called after gc_sweep_all

ports/stm32/main: Add mp_deinit() in main.

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