Implement support for the free-threaded build of CPython 3.13

PR #1015

Co-authored-by: J. Nick Koston <[email protected]>
Co-authored-by: Sviatoslav Sydorenko <[email protected]>

Author: 3 people

.github/workflows/ci-cd.yml

@@ -150,6 +150,7 @@ jobs:
     strategy:
       matrix:
         pyver:
+        - 3.13-freethreading
         - 3.13
         - 3.12
         - 3.11
@@ -163,6 +164,10 @@ jobs:
           no-extensions: Y
         - os: windows
           no-extensions: Y
+        - os: macos
+          pyver: 3.13-freethreading  # this is still tested within cibuildwheel
+        - os: windows
+          pyver: 3.13-freethreading  # this is still tested within cibuildwheel
         include:
         - pyver: pypy-3.8
           no-extensions: Y
@@ -195,11 +200,44 @@ jobs:
         path: dist
 
     - name: Setup Python ${{ matrix.pyver }}
-      id: python-install
+      if: >-
+        !endsWith(matrix.pyver, '-freethreading')
       uses: actions/setup-python@v5
       with:
         python-version: ${{ matrix.pyver }}
         allow-prereleases: true
+    - name: Setup Python ${{ matrix.pyver }}
+      if: endsWith(matrix.pyver, '-freethreading')
+      uses: deadsnakes/[email protected]
+      with:
+        python-version: 3.13-dev
+        nogil: true
+    - name: Compute runtime Python version
+      id: python-install
+      run: |
+        import sys
+        from os import environ
+        from pathlib import Path
+
+        FILE_APPEND_MODE = 'a'
+
+        python_version_str = ".".join(
+            map(str, sys.version_info[:3]),
+        )
+        freethreading_suffix = (
+            '' if sys.version_info < (3, 13) or sys._is_gil_enabled()
+            else 't'
+        )
+
+        with Path(environ['GITHUB_OUTPUT']).open(
+                mode=FILE_APPEND_MODE,
+        ) as outputs_file:
+            print(
+                f'python-version={python_version_str}{freethreading_suffix}',
+                file=outputs_file,
+            )
+      shell: python
+
     - name: Get pip cache dir
       id: pip-cache
       run: |

CHANGES/1015.feature.rst

@@ -0,0 +1 @@
+Implemented support for the free-threaded build of CPython 3.13 -- by :user:`lysnikolaou`.

CHANGES/1015.packaging.rst

@@ -0,0 +1 @@
+Started publishing wheels made for the free-threaded build of CPython 3.13 -- by :user:`lysnikolaou`.

docs/spelling_wordlist.txt

@@ -18,6 +18,7 @@ cChardet
 changelog
 charset
 charsetdetect
+CPython
 criterias
 css
 ctor

multidict/_multidict.c

@@ -1,6 +1,8 @@
 #include "Python.h"
 #include "structmember.h"
 
+#include "_multilib/pythoncapi_compat.h"
+
 // Include order important
 #include "_multilib/defs.h"
 #include "_multilib/istr.h"
@@ -155,13 +157,17 @@ _multidict_append_items_seq(MultiDictObject *self, PyObject *arg,
             Py_INCREF(value);
         }
         else if (PyList_CheckExact(item)) {
-            if (PyList_GET_SIZE(item) != 2) {
+            if (PyList_Size(item) != 2) {
+                goto invalid_type;
+            }
+            key = PyList_GetItemRef(item, 0);
+            if (key == NULL) {
+                goto invalid_type;
+            }
+            value = PyList_GetItemRef(item, 1);
+            if (value == NULL) {
                 goto invalid_type;
             }
-            key = PyList_GET_ITEM(item, 0);
-            Py_INCREF(key);
-            value = PyList_GET_ITEM(item, 1);
-            Py_INCREF(value);
         }
         else if (PySequence_Check(item)) {
             if (PySequence_Size(item) != 2) {
@@ -2070,6 +2076,13 @@ PyInit__multidict(void)
 
     /* Instantiate this module */
     module = PyModule_Create(&multidict_module);
+    if (module == NULL) {
+        goto fail;
+    }
+
+#ifdef Py_GIL_DISABLED
+    PyUnstable_Module_SetGIL(module, Py_MOD_GIL_NOT_USED);
+#endif
 
     Py_INCREF(&istr_type);
     if (PyModule_AddObject(

multidict/_multilib/pair_list.h

@@ -916,13 +916,18 @@ _pair_list_post_update(pair_list_t *list, PyObject* used_keys, Py_ssize_t pos)
 
     for (; pos < list->size; pos++) {
         pair = pair_list_get(list, pos);
-        tmp = PyDict_GetItem(used_keys, pair->identity);
-        if (tmp == NULL) {
+        int status = PyDict_GetItemRef(used_keys, pair->identity, &tmp);
+        if (status == -1) {
+            // exception set
+            return -1;
+        }
+        else if (status == 0) {
             // not found
             continue;
         }
 
         num = PyLong_AsSsize_t(tmp);
+        Py_DECREF(tmp);
         if (num == -1) {
             if (!PyErr_Occurred()) {
                 PyErr_SetString(PyExc_RuntimeError, "invalid internal state");
@@ -955,12 +960,18 @@ _pair_list_update(pair_list_t *list, PyObject *key,
     int found;
     int ident_cmp_res;
 
-    item = PyDict_GetItem(used_keys, identity);
-    if (item == NULL) {
+    int status = PyDict_GetItemRef(used_keys, identity, &item);
+    if (status == -1) {
+        // exception set
+        return -1;
+    }
+    else if (status == 0) {
+        // not found
         pos = 0;
     }
     else {
         pos = PyLong_AsSsize_t(item);
+        Py_DECREF(item);
         if (pos == -1) {
             if (!PyErr_Occurred()) {
                 PyErr_SetString(PyExc_RuntimeError, "invalid internal state");
@@ -1087,18 +1098,28 @@ pair_list_update_from_seq(pair_list_t *list, PyObject *seq)
         }
 
         // Convert item to sequence, and verify length 2.
+#ifdef Py_GIL_DISABLED
+        if (!PySequence_Check(item)) {
+#else
         fast = PySequence_Fast(item, "");
         if (fast == NULL) {
             if (PyErr_ExceptionMatches(PyExc_TypeError)) {
+#endif
                 PyErr_Format(PyExc_TypeError,
                              "multidict cannot convert sequence element #%zd"
                              " to a sequence",
                              i);
+#ifndef Py_GIL_DISABLED
             }
+#endif
             goto fail_1;
         }
 
+#ifdef Py_GIL_DISABLED
+        n = PySequence_Size(item);
+#else
         n = PySequence_Fast_GET_SIZE(fast);
+#endif
         if (n != 2) {
             PyErr_Format(PyExc_ValueError,
                          "multidict update sequence element #%zd "
@@ -1107,10 +1128,27 @@ pair_list_update_from_seq(pair_list_t *list, PyObject *seq)
             goto fail_1;
         }
 
+#ifdef Py_GIL_DISABLED
+        key = PySequence_ITEM(item, 0);
+        if (key == NULL) {
+            PyErr_Format(PyExc_ValueError,
+                         "multidict update sequence element #%zd's "
+                         "key could not be fetched", i);
+            goto fail_1;
+        }
+        value = PySequence_ITEM(item, 1);
+        if (value == NULL) {
+            PyErr_Format(PyExc_ValueError,
+                         "multidict update sequence element #%zd's "
+                         "value could not be fetched", i);
+            goto fail_1;
+        }
+#else
         key = PySequence_Fast_GET_ITEM(fast, 0);
         value = PySequence_Fast_GET_ITEM(fast, 1);
         Py_INCREF(key);
         Py_INCREF(value);
+#endif
 
         identity = pair_list_calc_identity(list, key);
         if (identity == NULL) {
@@ -1128,7 +1166,9 @@ pair_list_update_from_seq(pair_list_t *list, PyObject *seq)
 
         Py_DECREF(key);
         Py_DECREF(value);
+#ifndef Py_GIL_DISABLED
         Py_DECREF(fast);
+#endif
         Py_DECREF(item);
         Py_DECREF(identity);
     }