QUERY · ISSUE

py: settrace is incompatible with Interrupt Handlers

openby amirgonopened 2021-06-08updated 2021-06-09

py-core

When MICROPY_PY_SYS_SETTRACE is enabled, bytecode execution allocates RAM, which is forbidden on interrupt handlers.

https://github.com/micropython/micropython/blob/4d9e657f0ee881f4a41093ab89ec91d03613744d/py/vm.c#L142-L149

https://github.com/micropython/micropython/blob/e9e9c76ddf131f8e50b0ae2d44501d3cd88537ef/py/profile.c#L315-L318

CANDIDATE · ISSUE

py: code_state heap allocation is incompatible with Interrupt Handlers

closedby amirgonopened 2021-06-08updated 2021-06-26

py-core

When running interrupt handler, memory allocation is forbidden but still happens if state_size is larger than VM_MAX_STATE_ON_STACK:

https://github.com/micropython/micropython/blob/4d9e657f0ee881f4a41093ab89ec91d03613744d/py/objfun.c#L267-L268

It's not clear how to completely avoid memory allocations in interrupt handlers if code_state is allocated on heap sometimes.

Assessment

Q Qwen · high

Both issues address the same core problem: memory allocation in interrupt handlers is forbidden in MicroPython. Issue #7372 focuses on settrace functionality causing RAM allocation in py/vm.c and py/profile.c. Issue #7373 focuses on code_state heap allocation in py/objfun.c. While they share the same underlying constraint (no allocation in interrupts) and affect the same subsystem (py-core), they involve different code paths, different functions, and different root causes. They are separate bugs that happen to stem from the same architectural constraint.

Suggested action

Keep both issues open as they address distinct allocation problems in different code areas. Consider linking them as related issues since they share the same root constraint. A comprehensive fix might need to address both allocation paths.

py: settrace is incompatible with Interrupt Handlers

py: code_state heap allocation is incompatible with Interrupt Handlers

Keyboard