drop Python 3.9 (#656)

```
$ v3/bin/python -VV
Python 3.14.0 free-threading build (main, Oct  7 2025, 15:35:12) [Clang 20.1.4 ]

$ v3/bin/python -c 'import sys,msgpack; print(sys._is_gil_enabled())'
False
```

.github/workflows/test.yml

@@ -10,10 +10,8 @@ jobs:
     strategy:
       matrix:
         os: ["ubuntu-latest", "windows-latest", "windows-11-arm", "macos-latest"]
-        py: ["3.14-dev", "3.13", "3.12", "3.11", "3.10", "3.9"]
+        py: ["3.14", "3.14t", "3.13", "3.12", "3.11", "3.10"]
         exclude:
-          - os: windows-11-arm
-            py: "3.9"
           - os: windows-11-arm
             py: "3.10"
     runs-on: ${{ matrix.os }}
@@ -21,10 +19,10 @@ jobs:
 
     steps:
       - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v5
 
       - name: Set up Python
-        uses: actions/setup-python@v5
+        uses: actions/setup-python@v6
         with:
           python-version: ${{ matrix.py }}
           allow-prereleases: true
@@ -33,7 +31,6 @@ jobs:
       - name: Prepare
         shell: bash
         run: |
-          python -m pip install -U pip
           python -m pip install -r requirements.txt pytest
 
       - name: Build
@@ -55,8 +52,7 @@ jobs:
       - name: build packages
         shell: bash
         run: |
-          pip install build
-          python -m build
+          python -m build -nv
 
       - name: upload packages
         uses: actions/upload-artifact@v4

.github/workflows/wheel.yml

@@ -17,8 +17,8 @@ jobs:
     name: Build wheels on ${{ matrix.os }}
 
     steps:
-      - uses: actions/checkout@v4
-      - uses: actions/setup-python@v5
+      - uses: actions/checkout@v5
+      - uses: actions/setup-python@v6
         with:
           python-version: "3.x"
           cache: "pip"
@@ -33,7 +33,7 @@ jobs:
         env:
           CIBW_TEST_REQUIRES: "pytest"
           CIBW_TEST_COMMAND: "pytest {package}/test"
-          CIBW_SKIP: "pp* cp38-* cp39-win_arm64 cp310-win_arm64"
+          CIBW_SKIP: "pp* cp38-* cp39-* cp310-win_arm64"
 
       - name: Build sdist
         if: runner.os == 'Linux' && runner.arch == 'X64'

MANIFEST.in

@@ -1,5 +1,5 @@
 include setup.py
 include COPYING
 include README.md
-recursive-include msgpack *.h *.c *.pyx *.cpp
+recursive-include msgpack *.h *.c *.pyx
 recursive-include test *.py

msgpack/_cmsgpack.pyx

@@ -1,5 +1,6 @@
-# coding: utf-8
 #cython: embedsignature=True, c_string_encoding=ascii, language_level=3
+#cython: freethreading_compatible = True
+import cython
 from cpython.datetime cimport import_datetime, datetime_new
 import_datetime()
 

msgpack/_packer.pyx

@@ -1,5 +1,3 @@
-# coding: utf-8
-
 from cpython cimport *
 from cpython.bytearray cimport PyByteArray_Check, PyByteArray_CheckExact
 from cpython.datetime cimport (
@@ -129,6 +127,7 @@ cdef class Packer:
         if self.exports > 0:
             raise BufferError("Existing exports of data: Packer cannot be changed")
 
+    @cython.critical_section
     def __init__(self, *, default=None,
                  bint use_single_float=False, bint autoreset=True, bint use_bin_type=True,
                  bint strict_types=False, bint datetime=False, unicode_errors=None,
@@ -269,6 +268,7 @@ cdef class Packer:
                 return ret
         return self._pack_inner(o, 0, nest_limit)
 
+    @cython.critical_section
     def pack(self, object obj):
         cdef int ret
         self._check_exports()
@@ -284,6 +284,7 @@ cdef class Packer:
             self.pk.length = 0
             return buf
 
+    @cython.critical_section
     def pack_ext_type(self, typecode, data):
         self._check_exports()
         if len(data) > ITEM_LIMIT:
@@ -291,6 +292,7 @@ cdef class Packer:
         msgpack_pack_ext(&self.pk, typecode, len(data))
         msgpack_pack_raw_body(&self.pk, data, len(data))
 
+    @cython.critical_section
     def pack_array_header(self, long long size):
         self._check_exports()
         if size > ITEM_LIMIT:
@@ -301,6 +303,7 @@ cdef class Packer:
             self.pk.length = 0
             return buf
 
+    @cython.critical_section
     def pack_map_header(self, long long size):
         self._check_exports()
         if size > ITEM_LIMIT:
@@ -311,6 +314,7 @@ cdef class Packer:
             self.pk.length = 0
             return buf
 
+    @cython.critical_section
     def pack_map_pairs(self, object pairs):
         """
         Pack *pairs* as msgpack map type.
@@ -331,6 +335,7 @@ cdef class Packer:
             self.pk.length = 0
             return buf
 
+    @cython.critical_section
     def reset(self):
         """Reset internal buffer.
 
@@ -339,6 +344,7 @@ cdef class Packer:
         self._check_exports()
         self.pk.length = 0
 
+    @cython.critical_section
     def bytes(self):
         """Return internal buffer contents as bytes object"""
         return PyBytes_FromStringAndSize(self.pk.buf, self.pk.length)

msgpack/_unpacker.pyx

@@ -1,5 +1,3 @@
-# coding: utf-8
-
 from cpython cimport *
 cdef extern from "Python.h":
     ctypedef struct PyObject
@@ -324,6 +322,7 @@ cdef class Unpacker:
         PyMem_Free(self.buf)
         self.buf = NULL
 
+    @cython.critical_section
     def __init__(self, file_like=None, *, Py_ssize_t read_size=0,
                  bint use_list=True, bint raw=False, int timestamp=0, bint strict_map_key=True,
                  object object_hook=None, object object_pairs_hook=None, object list_hook=None,
@@ -384,6 +383,7 @@ cdef class Unpacker:
                  max_str_len, max_bin_len, max_array_len,
                  max_map_len, max_ext_len)
 
+    @cython.critical_section
     def feed(self, object next_bytes):
         """Append `next_bytes` to internal buffer."""
         cdef Py_buffer pybuff
@@ -484,6 +484,7 @@ cdef class Unpacker:
             else:
                 raise ValueError("Unpack failed: error = %d" % (ret,))
 
+    @cython.critical_section
     def read_bytes(self, Py_ssize_t nbytes):
         """Read a specified number of raw bytes from the stream"""
         cdef Py_ssize_t nread
@@ -496,6 +497,7 @@ cdef class Unpacker:
         self.stream_offset += nread
         return ret
 
+    @cython.critical_section
     def unpack(self):
         """Unpack one object
 
@@ -503,6 +505,7 @@ cdef class Unpacker:
         """
         return self._unpack(unpack_construct)
 
+    @cython.critical_section
     def skip(self):
         """Read and ignore one object, returning None
 
@@ -510,6 +513,7 @@ cdef class Unpacker:
         """
         return self._unpack(unpack_skip)
 
+    @cython.critical_section
     def read_array_header(self):
         """assuming the next object is an array, return its size n, such that
         the next n unpack() calls will iterate over its contents.
@@ -518,6 +522,7 @@ cdef class Unpacker:
         """
         return self._unpack(read_array_header)
 
+    @cython.critical_section
     def read_map_header(self):
         """assuming the next object is a map, return its size n, such that the
         next n * 2 unpack() calls will iterate over its key-value pairs.
@@ -526,6 +531,7 @@ cdef class Unpacker:
         """
         return self._unpack(read_map_header)
 
+    @cython.critical_section
     def tell(self):
         """Returns the current position of the Unpacker in bytes, i.e., the
         number of bytes that were read from the input, also the starting
@@ -536,6 +542,7 @@ cdef class Unpacker:
     def __iter__(self):
         return self
 
+    @cython.critical_section
     def __next__(self):
         return self._unpack(unpack_construct, 1)
 

pyproject.toml

@@ -1,5 +1,5 @@
 [build-system]
-requires = ["setuptools >= 80.9.0"]
+requires = ["setuptools >= 78.1.1"]
 build-backend = "setuptools.build_meta"
 
 [project]
@@ -10,7 +10,7 @@ authors = [{name="Inada Naoki", email="songofacandy@gmail.com"}]
 description = "MessagePack serializer"
 readme = "README.md"
 keywords = ["msgpack", "messagepack", "serializer", "serialization", "binary"]
-requires-python = ">=3.9"
+requires-python = ">=3.10"
 classifiers = [
     "Development Status :: 5 - Production/Stable",
     "Operating System :: OS Independent",
@@ -36,7 +36,7 @@ version = {attr = "msgpack.__version__"}
 
 [tool.ruff]
 line-length = 100
-target-version = "py39"
+target-version = "py310"
 lint.select = [
     "E", # pycodestyle
     "F", # Pyflakes

requirements.txt

@@ -1 +1,3 @@
 Cython==3.1.4
+setuptools==78.1.1
+build