PYTHON-4450 Support free-threaded Python with no-GIL

Author: ShaneHarvey

.github/workflows/dist.yml

@@ -67,7 +67,7 @@ jobs:
         # Note: the default manylinux is manylinux2014
         run: |
           python -m pip install -U pip
-          python -m pip install "cibuildwheel>=2.17,<3"
+          python -m pip install "cibuildwheel>=2.20,<3"
 
       - name: Build wheels
         env:

bson/_cbsonmodule.c

@@ -3184,6 +3184,9 @@ static PyModuleDef_Slot _cbson_slots[] = {
     {Py_mod_exec, _cbson_exec},
 #if defined(Py_MOD_MULTIPLE_INTERPRETERS_SUPPORTED)
     {Py_mod_multiple_interpreters, Py_MOD_MULTIPLE_INTERPRETERS_SUPPORTED},
+#endif
+#if PY_VERSION_HEX >= 0x030D0000
+    {Py_mod_gil, Py_MOD_GIL_NOT_USED},
 #endif
     {0, NULL},
 };

pymongo/_cmessagemodule.c

@@ -1022,6 +1022,9 @@ static PyModuleDef_Slot _cmessage_slots[] = {
     {Py_mod_exec, _cmessage_exec},
 #ifdef Py_MOD_MULTIPLE_INTERPRETERS_SUPPORTED
     {Py_mod_multiple_interpreters, Py_MOD_MULTIPLE_INTERPRETERS_SUPPORTED},
+#endif
+#if PY_VERSION_HEX >= 0x030D0000
+    {Py_mod_gil, Py_MOD_GIL_NOT_USED},
 #endif
     {0, NULL},
 };

pyproject.toml

@@ -236,6 +236,8 @@ partial_branches = ["if (.*and +)*not _use_c( and.*)*:"]
 directory = "htmlcov"
 
 [tool.cibuildwheel]
+# Enable free-threaded support
+free-threaded-support = true
 skip = "pp* *-musllinux*"
 build-frontend = "build"
 test-command = "python {project}/tools/fail_if_no_c.py"