ports/unix/modffi.c: FFI fixes. #7401
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ports/unix/modffi.c
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| (void)flags; | ||
| mp_obj_fficallback_t *self = MP_OBJ_TO_PTR(self_in); | ||
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| bufinfo->buf = &self->func; |
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This doesn't feel like the right approach, using the buffer protocol to get out the C closure wrapper function (I would expect it to get access to the underlying data of the function itself).
Instead I'd suggest to add a method to the callback type, eg cfun(). Then one can write:
sa.sa_handler = cb.cfun()There was a problem hiding this comment.
Done.
However, sa.sa_handler = cb.cfun() doesn't work in this case because we want to set the pointer value, not the value the pointer points at.
So we need something like this instead:
memoryview(sa.sa_handler)[:] = cb.cfun()There was a problem hiding this comment.
However,
sa.sa_handler = cb.cfun()doesn't work in this case because we want to set the pointer value, not the value the pointer points at.
If sa_handler were defined as a UINT64 would it work without the memoryview?
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Yes, you are right.
I changed cfun to return ULL integer and defined sa.sa_handler as uctypes.UINT64, it works fine.
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I'm not sure why "coverage/coveralls" test fails. |
| for (uint i = 0; i < cif->nargs; i++) { | ||
| pyargs[i] = mp_obj_new_int(*(mp_int_t *)args[i]); | ||
| } | ||
| mp_obj_t res = mp_call_function_n_kw(MP_OBJ_FROM_PTR(func), cif->nargs, 0, pyargs); | ||
| mp_obj_t res = mp_call_function_n_kw(pyfunc, cif->nargs, 0, pyargs); |
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If this call raises an exception, and locking is enabled, then things will not go well, the GC will remain locked and the code will fail completely.
I think it makes sense to have two separate callback functions: call_py_func and call_py_func_with_lock. The correct one is registered with ffi_prep_closure_loc. The wrapper call_py_func_with_lock will do something similar to lib/utils/mpirq.c:mp_irq_handler.
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Fixes and improvements to ffi callback Added an optional 'lock' kwarg to callback that locks gc and scheduler. This allows the callback to be invoked asynchronously in 'interrupt context', for example as a signal handler. Added 'cfun' member function to callback, that allows retrieving the C callback function address. This is needed when the callback should be set to a struct field. Signed-off-by: Amir Gonnen <amirgonnen@gmail.com>
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Thanks for updating. Merged in cb332dd with some minor edits (use mp_printf instead of printf). |
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Fixes and improvements to ffi callback
Add an optional 'lock' kwarg to callback that locks gc and scheduler.
This allows the callback to be invoked asynchronously in 'interrupt
context', for example as a signal handler
Added buffer protocol to callback that allows retrieving the C callback
function. This is needed when the callback should be set to a struct
field.
Usage example - Creating a signal handler and setting sa_handler to it:
Related: #7373