Feature or enhancement

PEP 703 in large part relies on replacing the GIL with fine grained per-object locks. The primary way to acquire and release these locks is through the critical section API (#111569). It would be helpful if argument clinic could auto generate the API calls in the binding code when specified.

For example, thebufferedio.c will require per-object locking around most calls for thread-safety in--disable-gil builds.

As an example, the_io._Buffered.close function is written as:

We might add a@critical_section directive to designate that argument clinic should generatePy_BEGIN_CRITICAL_SECTION() andPy_END_CRITICAL_SECTION() in the binding code before calling_io__Buffered_close_impl.

/*[clinic input]@critical_section_io._Buffered.close[clinic start generated code]*/staticPyObject*_io__Buffered_close_impl(buffered*self)/*[clinic end generated code: output=7280b7b42033be0c input=d20b83d1ddd7d805]*/

The generated binding code inbufferedio.c.h would then look like:

staticPyObject*_io__Buffered_close(buffered*self,PyObject*Py_UNUSED(ignored)){PyObject*return_value=NULL;Py_BEGIN_CRITICAL_SECTION(self);return_value=_io__Buffered_close_impl(self);Py_END_CRITICAL_SECTION();returnreturn_value;}

Note thatPy_BEGIN/END_CRITICAL_SECTION() are no-ops in the default build.

Linked PRs

• gh-111903: Add@critical_section directive to Argument Clinic. #111904
• gh-111903: Update AC to support "pycore_critical_section.h" header #112251