From 14f923e938d89053653d3722770d81f8a5c814db Mon Sep 17 00:00:00 2001
From: "Erlend E. Aasland" <erlend.aasland@protonmail.com>
Date: Tue, 9 May 2023 18:04:11 +0200
Subject: [PATCH 01/12] Refactor: replace query with parameter

Pass module state to bufferediobase_unsupported()
---
 Modules/_io/bufferedio.c | 21 ++++++++++++---------
 1 file changed, 12 insertions(+), 9 deletions(-)

diff --git a/Modules/_io/bufferedio.c b/Modules/_io/bufferedio.c
index 723d16b47fef9f..3c6f98f345fd01 100644
--- a/Modules/_io/bufferedio.c
+++ b/Modules/_io/bufferedio.c
@@ -106,11 +106,9 @@ _io__BufferedIOBase_readinto1_impl(PyObject *self, Py_buffer *buffer)
 }
 
 static PyObject *
-bufferediobase_unsupported(const char *message)
+bufferediobase_unsupported(_PyIO_State *state, const char *message)
 {
-    _PyIO_State *state = IO_STATE();
-    if (state != NULL)
-        PyErr_SetString(state->unsupported_operation, message);
+    PyErr_SetString(state->unsupported_operation, message);
     return NULL;
 }
 
@@ -127,7 +125,8 @@ static PyObject *
 _io__BufferedIOBase_detach_impl(PyObject *self)
 /*[clinic end generated code: output=754977c8d10ed88c input=822427fb58fe4169]*/
 {
-    return bufferediobase_unsupported("detach");
+    _PyIO_State *state = IO_STATE();
+    return bufferediobase_unsupported(state, "detach");
 }
 
 PyDoc_STRVAR(bufferediobase_read_doc,
@@ -151,7 +150,8 @@ PyDoc_STRVAR(bufferediobase_read_doc,
 static PyObject *
 bufferediobase_read(PyObject *self, PyObject *args)
 {
-    return bufferediobase_unsupported("read");
+    _PyIO_State *state = IO_STATE();
+    return bufferediobase_unsupported(state, "read");
 }
 
 PyDoc_STRVAR(bufferediobase_read1_doc,
@@ -164,7 +164,8 @@ PyDoc_STRVAR(bufferediobase_read1_doc,
 static PyObject *
 bufferediobase_read1(PyObject *self, PyObject *args)
 {
-    return bufferediobase_unsupported("read1");
+    _PyIO_State *state = IO_STATE();
+    return bufferediobase_unsupported(state, "read1");
 }
 
 PyDoc_STRVAR(bufferediobase_write_doc,
@@ -179,7 +180,8 @@ PyDoc_STRVAR(bufferediobase_write_doc,
 static PyObject *
 bufferediobase_write(PyObject *self, PyObject *args)
 {
-    return bufferediobase_unsupported("write");
+    _PyIO_State *state = IO_STATE();
+    return bufferediobase_unsupported(state, "write");
 }
 
 
@@ -1298,7 +1300,8 @@ _io__Buffered_truncate_impl(buffered *self, PyObject *pos)
     CHECK_INITIALIZED(self)
     CHECK_CLOSED(self, "truncate of closed file")
     if (!self->writable) {
-        return bufferediobase_unsupported("truncate");
+        _PyIO_State *state = IO_STATE();
+        return bufferediobase_unsupported(state, "truncate");
     }
     if (!ENTER_BUFFERED(self))
         return NULL;

From 482f13404ff6a7d1e1b3c4f158de641939bf0b7c Mon Sep 17 00:00:00 2001
From: "Erlend E. Aasland" <erlend.aasland@protonmail.com>
Date: Tue, 9 May 2023 18:04:51 +0200
Subject: [PATCH 02/12] Refactor: replace query with parameter

Pass module state to iobase_unsupported()
---
 Modules/_io/iobase.c | 24 ++++++++++++++----------
 1 file changed, 14 insertions(+), 10 deletions(-)

diff --git a/Modules/_io/iobase.c b/Modules/_io/iobase.c
index 682ed000eb1fd9..b08e679fb2a219 100644
--- a/Modules/_io/iobase.c
+++ b/Modules/_io/iobase.c
@@ -71,11 +71,9 @@ PyDoc_STRVAR(iobase_doc,
 
 /* Internal methods */
 static PyObject *
-iobase_unsupported(const char *message)
+iobase_unsupported(_PyIO_State *state, const char *message)
 {
-    _PyIO_State *state = IO_STATE();
-    if (state != NULL)
-        PyErr_SetString(state->unsupported_operation, message);
+    PyErr_SetString(state->unsupported_operation, message);
     return NULL;
 }
 
@@ -97,7 +95,8 @@ PyDoc_STRVAR(iobase_seek_doc,
 static PyObject *
 iobase_seek(PyObject *self, PyObject *args)
 {
-    return iobase_unsupported("seek");
+    _PyIO_State *state = IO_STATE();
+    return iobase_unsupported(state, "seek");
 }
 
 /*[clinic input]
@@ -122,7 +121,8 @@ PyDoc_STRVAR(iobase_truncate_doc,
 static PyObject *
 iobase_truncate(PyObject *self, PyObject *args)
 {
-    return iobase_unsupported("truncate");
+    _PyIO_State *state = IO_STATE();
+    return iobase_unsupported(state, "truncate");
 }
 
 static int
@@ -379,7 +379,8 @@ _PyIOBase_check_seekable(PyObject *self, PyObject *args)
         return NULL;
     if (res != Py_True) {
         Py_CLEAR(res);
-        iobase_unsupported("File or stream is not seekable.");
+        _PyIO_State *state = IO_STATE();
+        iobase_unsupported(state, "File or stream is not seekable.");
         return NULL;
     }
     if (args == Py_True) {
@@ -412,7 +413,8 @@ _PyIOBase_check_readable(PyObject *self, PyObject *args)
         return NULL;
     if (res != Py_True) {
         Py_CLEAR(res);
-        iobase_unsupported("File or stream is not readable.");
+        _PyIO_State *state = IO_STATE();
+        iobase_unsupported(state, "File or stream is not readable.");
         return NULL;
     }
     if (args == Py_True) {
@@ -445,7 +447,8 @@ _PyIOBase_check_writable(PyObject *self, PyObject *args)
         return NULL;
     if (res != Py_True) {
         Py_CLEAR(res);
-        iobase_unsupported("File or stream is not writable.");
+        _PyIO_State *state = IO_STATE();
+        iobase_unsupported(state, "File or stream is not writable.");
         return NULL;
     }
     if (args == Py_True) {
@@ -487,7 +490,8 @@ static PyObject *
 _io__IOBase_fileno_impl(PyObject *self)
 /*[clinic end generated code: output=7cc0973f0f5f3b73 input=4e37028947dc1cc8]*/
 {
-    return iobase_unsupported("fileno");
+    _PyIO_State *state = IO_STATE();
+    return iobase_unsupported(state, "fileno");
 }
 
 /*[clinic input]

From 8adc0cd0e7eb3b295f7455eeedb6fc31b2c9d391 Mon Sep 17 00:00:00 2001
From: "Erlend E. Aasland" <erlend.aasland@protonmail.com>
Date: Tue, 9 May 2023 18:20:50 +0200
Subject: [PATCH 03/12] Refactor: hide delegate

Add method wrapper for _PyIOBase_check_seekable.
---
 Modules/_io/iobase.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/Modules/_io/iobase.c b/Modules/_io/iobase.c
index b08e679fb2a219..423aa5a6a5d051 100644
--- a/Modules/_io/iobase.c
+++ b/Modules/_io/iobase.c
@@ -204,6 +204,12 @@ _PyIOBase_check_closed(PyObject *self, PyObject *args)
     Py_RETURN_NONE;
 }
 
+static PyObject *
+iobase_check_seekable(PyObject *self, PyObject *args)
+{
+    return _PyIOBase_check_seekable(self, args);
+}
+
 /* XXX: IOBase thinks it has to maintain its own internal state in
    `__IOBase_closed` and call flush() by itself, but it is redundant with
    whatever behaviour a non-trivial derived class will implement. */
@@ -802,7 +808,7 @@ static PyMethodDef iobase_methods[] = {
     _IO__IOBASE_WRITABLE_METHODDEF
 
     {"_checkClosed",   _PyIOBase_check_closed, METH_NOARGS},
-    {"_checkSeekable", _PyIOBase_check_seekable, METH_NOARGS},
+    {"_checkSeekable", iobase_check_seekable, METH_NOARGS},
     {"_checkReadable", _PyIOBase_check_readable, METH_NOARGS},
     {"_checkWritable", _PyIOBase_check_writable, METH_NOARGS},
 

From 703440a7e1717d518ac5b848e6fe72dc002d8bf1 Mon Sep 17 00:00:00 2001
From: "Erlend E. Aasland" <erlend.aasland@protonmail.com>
Date: Tue, 9 May 2023 18:22:47 +0200
Subject: [PATCH 04/12] Refactor: hide delegate

Add method wraper for _PyIOBase_check_readable
---
 Modules/_io/iobase.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/Modules/_io/iobase.c b/Modules/_io/iobase.c
index 423aa5a6a5d051..f8f58577a964d8 100644
--- a/Modules/_io/iobase.c
+++ b/Modules/_io/iobase.c
@@ -210,6 +210,12 @@ iobase_check_seekable(PyObject *self, PyObject *args)
     return _PyIOBase_check_seekable(self, args);
 }
 
+static PyObject *
+iobase_check_readable(PyObject *self, PyObject *args)
+{
+    return _PyIOBase_check_readable(self, args);
+}
+
 /* XXX: IOBase thinks it has to maintain its own internal state in
    `__IOBase_closed` and call flush() by itself, but it is redundant with
    whatever behaviour a non-trivial derived class will implement. */
@@ -809,7 +815,7 @@ static PyMethodDef iobase_methods[] = {
 
     {"_checkClosed",   _PyIOBase_check_closed, METH_NOARGS},
     {"_checkSeekable", iobase_check_seekable, METH_NOARGS},
-    {"_checkReadable", _PyIOBase_check_readable, METH_NOARGS},
+    {"_checkReadable", iobase_check_readable, METH_NOARGS},
     {"_checkWritable", _PyIOBase_check_writable, METH_NOARGS},
 
     _IO__IOBASE_FILENO_METHODDEF

From ea9c0989813665aae0cf757f56dc8b985aa9bdef Mon Sep 17 00:00:00 2001
From: "Erlend E. Aasland" <erlend.aasland@protonmail.com>
Date: Tue, 9 May 2023 18:24:21 +0200
Subject: [PATCH 05/12] Refactor: hide delegate

Add method wraper for _PyIOBase_check_writable
---
 Modules/_io/iobase.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/Modules/_io/iobase.c b/Modules/_io/iobase.c
index f8f58577a964d8..90537c00c11133 100644
--- a/Modules/_io/iobase.c
+++ b/Modules/_io/iobase.c
@@ -216,6 +216,12 @@ iobase_check_readable(PyObject *self, PyObject *args)
     return _PyIOBase_check_readable(self, args);
 }
 
+static PyObject *
+iobase_check_writable(PyObject *self, PyObject *args)
+{
+    return _PyIOBase_check_writable(self, args);
+}
+
 /* XXX: IOBase thinks it has to maintain its own internal state in
    `__IOBase_closed` and call flush() by itself, but it is redundant with
    whatever behaviour a non-trivial derived class will implement. */
@@ -816,7 +822,7 @@ static PyMethodDef iobase_methods[] = {
     {"_checkClosed",   _PyIOBase_check_closed, METH_NOARGS},
     {"_checkSeekable", iobase_check_seekable, METH_NOARGS},
     {"_checkReadable", iobase_check_readable, METH_NOARGS},
-    {"_checkWritable", _PyIOBase_check_writable, METH_NOARGS},
+    {"_checkWritable", iobase_check_writable, METH_NOARGS},
 
     _IO__IOBASE_FILENO_METHODDEF
     _IO__IOBASE_ISATTY_METHODDEF

From e940ed3631cc57df552bb2b8454ae2817b3c114b Mon Sep 17 00:00:00 2001
From: "Erlend E. Aasland" <erlend.aasland@protonmail.com>
Date: Tue, 9 May 2023 18:33:04 +0200
Subject: [PATCH 06/12] Add io state struct forward declaration.

---
 Modules/_io/_iomodule.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/Modules/_io/_iomodule.h b/Modules/_io/_iomodule.h
index 1bf301c9cf0a94..157055f9006d42 100644
--- a/Modules/_io/_iomodule.h
+++ b/Modules/_io/_iomodule.h
@@ -34,6 +34,7 @@ extern PyType_Spec winconsoleio_spec;
  * with args=NULL, and return a new reference.
  * BUT when args=Py_True is passed, they return a borrowed reference.
  */
+struct _io_state;  // Forward decl.
 extern PyObject* _PyIOBase_check_readable(PyObject *self, PyObject *args);
 extern PyObject* _PyIOBase_check_writable(PyObject *self, PyObject *args);
 extern PyObject* _PyIOBase_check_seekable(PyObject *self, PyObject *args);
@@ -140,7 +141,7 @@ extern Py_off_t PyNumber_AsOff_t(PyObject *item, PyObject *err);
 
 extern PyModuleDef _PyIO_Module;
 
-typedef struct {
+typedef struct _io_state {
     int initialized;
     PyObject *unsupported_operation;
 

From c68d657173994b1b3d7be543ae6bd789838f313f Mon Sep 17 00:00:00 2001
From: "Erlend E. Aasland" <erlend.aasland@protonmail.com>
Date: Tue, 9 May 2023 18:31:31 +0200
Subject: [PATCH 07/12] Refactor: replace query with parameter

Pass module state to _PyIOBase_check_seekable()
---
 Modules/_io/_iomodule.h  | 3 ++-
 Modules/_io/bufferedio.c | 9 ++++++---
 Modules/_io/iobase.c     | 6 +++---
 3 files changed, 11 insertions(+), 7 deletions(-)

diff --git a/Modules/_io/_iomodule.h b/Modules/_io/_iomodule.h
index 157055f9006d42..603f2caf31dff0 100644
--- a/Modules/_io/_iomodule.h
+++ b/Modules/_io/_iomodule.h
@@ -37,7 +37,8 @@ extern PyType_Spec winconsoleio_spec;
 struct _io_state;  // Forward decl.
 extern PyObject* _PyIOBase_check_readable(PyObject *self, PyObject *args);
 extern PyObject* _PyIOBase_check_writable(PyObject *self, PyObject *args);
-extern PyObject* _PyIOBase_check_seekable(PyObject *self, PyObject *args);
+extern PyObject* _PyIOBase_check_seekable(struct _io_state *state,
+                                          PyObject *self, PyObject *args);
 extern PyObject* _PyIOBase_check_closed(PyObject *self, PyObject *args);
 
 /* Helper for finalization.
diff --git a/Modules/_io/bufferedio.c b/Modules/_io/bufferedio.c
index 3c6f98f345fd01..be875e017bf29e 100644
--- a/Modules/_io/bufferedio.c
+++ b/Modules/_io/bufferedio.c
@@ -1224,8 +1224,10 @@ _io__Buffered_seek_impl(buffered *self, PyObject *targetobj, int whence)
 
     CHECK_CLOSED(self, "seek of closed file")
 
-    if (_PyIOBase_check_seekable(self->raw, Py_True) == NULL)
+    _PyIO_State *state = IO_STATE();
+    if (_PyIOBase_check_seekable(state, self->raw, Py_True) == NULL) {
         return NULL;
+    }
 
     target = PyNumber_AsOff_t(targetobj, PyExc_ValueError);
     if (target == -1 && PyErr_Occurred())
@@ -2293,8 +2295,10 @@ _io_BufferedRandom___init___impl(buffered *self, PyObject *raw,
     self->ok = 0;
     self->detached = 0;
 
-    if (_PyIOBase_check_seekable(raw, Py_True) == NULL)
+    _PyIO_State *state = find_io_state_by_def(Py_TYPE(self));
+    if (_PyIOBase_check_seekable(state, raw, Py_True) == NULL) {
         return -1;
+    }
     if (_PyIOBase_check_readable(raw, Py_True) == NULL)
         return -1;
     if (_PyIOBase_check_writable(raw, Py_True) == NULL)
@@ -2312,7 +2316,6 @@ _io_BufferedRandom___init___impl(buffered *self, PyObject *raw,
     _bufferedwriter_reset_buf(self);
     self->pos = 0;
 
-    _PyIO_State *state = find_io_state_by_def(Py_TYPE(self));
     self->fast_closed_checks = (Py_IS_TYPE(self, state->PyBufferedRandom_Type) &&
                                 Py_IS_TYPE(raw, state->PyFileIO_Type));
 
diff --git a/Modules/_io/iobase.c b/Modules/_io/iobase.c
index 90537c00c11133..7898fae6c35ec4 100644
--- a/Modules/_io/iobase.c
+++ b/Modules/_io/iobase.c
@@ -207,7 +207,8 @@ _PyIOBase_check_closed(PyObject *self, PyObject *args)
 static PyObject *
 iobase_check_seekable(PyObject *self, PyObject *args)
 {
-    return _PyIOBase_check_seekable(self, args);
+    _PyIO_State *state = IO_STATE();
+    return _PyIOBase_check_seekable(state, self, args);
 }
 
 static PyObject *
@@ -390,14 +391,13 @@ _io__IOBase_seekable_impl(PyObject *self)
 }
 
 PyObject *
-_PyIOBase_check_seekable(PyObject *self, PyObject *args)
+_PyIOBase_check_seekable(_PyIO_State *state, PyObject *self, PyObject *args)
 {
     PyObject *res  = PyObject_CallMethodNoArgs(self, &_Py_ID(seekable));
     if (res == NULL)
         return NULL;
     if (res != Py_True) {
         Py_CLEAR(res);
-        _PyIO_State *state = IO_STATE();
         iobase_unsupported(state, "File or stream is not seekable.");
         return NULL;
     }

From 0084715e00725c660a796c15cc7f8710ab8061db Mon Sep 17 00:00:00 2001
From: "Erlend E. Aasland" <erlend.aasland@protonmail.com>
Date: Tue, 9 May 2023 18:38:03 +0200
Subject: [PATCH 08/12] Refactor: replace query with parameter

Pass module state to _PyIOBase_check_readable()
---
 Modules/_io/_iomodule.h  |  3 ++-
 Modules/_io/bufferedio.c | 13 ++++++++-----
 Modules/_io/iobase.c     |  6 +++---
 3 files changed, 13 insertions(+), 9 deletions(-)

diff --git a/Modules/_io/_iomodule.h b/Modules/_io/_iomodule.h
index 603f2caf31dff0..30299014fbe28b 100644
--- a/Modules/_io/_iomodule.h
+++ b/Modules/_io/_iomodule.h
@@ -35,7 +35,8 @@ extern PyType_Spec winconsoleio_spec;
  * BUT when args=Py_True is passed, they return a borrowed reference.
  */
 struct _io_state;  // Forward decl.
-extern PyObject* _PyIOBase_check_readable(PyObject *self, PyObject *args);
+extern PyObject* _PyIOBase_check_readable(struct _io_state *state,
+                                          PyObject *self, PyObject *args);
 extern PyObject* _PyIOBase_check_writable(PyObject *self, PyObject *args);
 extern PyObject* _PyIOBase_check_seekable(struct _io_state *state,
                                           PyObject *self, PyObject *args);
diff --git a/Modules/_io/bufferedio.c b/Modules/_io/bufferedio.c
index be875e017bf29e..d773e975ee2f92 100644
--- a/Modules/_io/bufferedio.c
+++ b/Modules/_io/bufferedio.c
@@ -1424,8 +1424,10 @@ _io_BufferedReader___init___impl(buffered *self, PyObject *raw,
     self->ok = 0;
     self->detached = 0;
 
-    if (_PyIOBase_check_readable(raw, Py_True) == NULL)
+    _PyIO_State *state = find_io_state_by_def(Py_TYPE(self));
+    if (_PyIOBase_check_readable(state, raw, Py_True) == NULL) {
         return -1;
+    }
 
     Py_XSETREF(self->raw, Py_NewRef(raw));
     self->buffer_size = buffer_size;
@@ -1436,7 +1438,6 @@ _io_BufferedReader___init___impl(buffered *self, PyObject *raw,
         return -1;
     _bufferedreader_reset_buf(self);
 
-    _PyIO_State *state = find_io_state_by_def(Py_TYPE(self));
     self->fast_closed_checks = (
         Py_IS_TYPE(self, state->PyBufferedReader_Type) &&
         Py_IS_TYPE(raw, state->PyFileIO_Type)
@@ -2097,12 +2098,13 @@ _io_BufferedRWPair___init___impl(rwpair *self, PyObject *reader,
                                  PyObject *writer, Py_ssize_t buffer_size)
 /*[clinic end generated code: output=327e73d1aee8f984 input=620d42d71f33a031]*/
 {
-    if (_PyIOBase_check_readable(reader, Py_True) == NULL)
+    _PyIO_State *state = find_io_state_by_def(Py_TYPE(self));
+    if (_PyIOBase_check_readable(state, reader, Py_True) == NULL) {
         return -1;
+    }
     if (_PyIOBase_check_writable(writer, Py_True) == NULL)
         return -1;
 
-    _PyIO_State *state = find_io_state_by_def(Py_TYPE(self));
     self->reader = (buffered *) PyObject_CallFunction(
             (PyObject *)state->PyBufferedReader_Type,
             "On", reader, buffer_size);
@@ -2299,8 +2301,9 @@ _io_BufferedRandom___init___impl(buffered *self, PyObject *raw,
     if (_PyIOBase_check_seekable(state, raw, Py_True) == NULL) {
         return -1;
     }
-    if (_PyIOBase_check_readable(raw, Py_True) == NULL)
+    if (_PyIOBase_check_readable(state, raw, Py_True) == NULL) {
         return -1;
+    }
     if (_PyIOBase_check_writable(raw, Py_True) == NULL)
         return -1;
 
diff --git a/Modules/_io/iobase.c b/Modules/_io/iobase.c
index 7898fae6c35ec4..fbafdbc48925b4 100644
--- a/Modules/_io/iobase.c
+++ b/Modules/_io/iobase.c
@@ -214,7 +214,8 @@ iobase_check_seekable(PyObject *self, PyObject *args)
 static PyObject *
 iobase_check_readable(PyObject *self, PyObject *args)
 {
-    return _PyIOBase_check_readable(self, args);
+    _PyIO_State *state = IO_STATE();
+    return _PyIOBase_check_readable(state, self, args);
 }
 
 static PyObject *
@@ -424,14 +425,13 @@ _io__IOBase_readable_impl(PyObject *self)
 
 /* May be called with any object */
 PyObject *
-_PyIOBase_check_readable(PyObject *self, PyObject *args)
+_PyIOBase_check_readable(_PyIO_State *state, PyObject *self, PyObject *args)
 {
     PyObject *res = PyObject_CallMethodNoArgs(self, &_Py_ID(readable));
     if (res == NULL)
         return NULL;
     if (res != Py_True) {
         Py_CLEAR(res);
-        _PyIO_State *state = IO_STATE();
         iobase_unsupported(state, "File or stream is not readable.");
         return NULL;
     }

From 20777e7d45ebb906653217b4ffd423bfbec2130d Mon Sep 17 00:00:00 2001
From: "Erlend E. Aasland" <erlend.aasland@protonmail.com>
Date: Tue, 9 May 2023 18:40:12 +0200
Subject: [PATCH 09/12] Refactor: replace query with parameter

Pass module state to _PyIOBase_check_writable()
---
 Modules/_io/_iomodule.h  |  3 ++-
 Modules/_io/bufferedio.c | 11 +++++++----
 Modules/_io/iobase.c     |  6 +++---
 3 files changed, 12 insertions(+), 8 deletions(-)

diff --git a/Modules/_io/_iomodule.h b/Modules/_io/_iomodule.h
index 30299014fbe28b..5c6124eb88e21e 100644
--- a/Modules/_io/_iomodule.h
+++ b/Modules/_io/_iomodule.h
@@ -37,7 +37,8 @@ extern PyType_Spec winconsoleio_spec;
 struct _io_state;  // Forward decl.
 extern PyObject* _PyIOBase_check_readable(struct _io_state *state,
                                           PyObject *self, PyObject *args);
-extern PyObject* _PyIOBase_check_writable(PyObject *self, PyObject *args);
+extern PyObject* _PyIOBase_check_writable(struct _io_state *state,
+                                          PyObject *self, PyObject *args);
 extern PyObject* _PyIOBase_check_seekable(struct _io_state *state,
                                           PyObject *self, PyObject *args);
 extern PyObject* _PyIOBase_check_closed(PyObject *self, PyObject *args);
diff --git a/Modules/_io/bufferedio.c b/Modules/_io/bufferedio.c
index d773e975ee2f92..98abf7e7345846 100644
--- a/Modules/_io/bufferedio.c
+++ b/Modules/_io/bufferedio.c
@@ -1780,8 +1780,10 @@ _io_BufferedWriter___init___impl(buffered *self, PyObject *raw,
     self->ok = 0;
     self->detached = 0;
 
-    if (_PyIOBase_check_writable(raw, Py_True) == NULL)
+    _PyIO_State *state = find_io_state_by_def(Py_TYPE(self));
+    if (_PyIOBase_check_writable(state, raw, Py_True) == NULL) {
         return -1;
+    }
 
     Py_INCREF(raw);
     Py_XSETREF(self->raw, raw);
@@ -1794,7 +1796,6 @@ _io_BufferedWriter___init___impl(buffered *self, PyObject *raw,
     _bufferedwriter_reset_buf(self);
     self->pos = 0;
 
-    _PyIO_State *state = find_io_state_by_def(Py_TYPE(self));
     self->fast_closed_checks = (
         Py_IS_TYPE(self, state->PyBufferedWriter_Type) &&
         Py_IS_TYPE(raw, state->PyFileIO_Type)
@@ -2102,8 +2103,9 @@ _io_BufferedRWPair___init___impl(rwpair *self, PyObject *reader,
     if (_PyIOBase_check_readable(state, reader, Py_True) == NULL) {
         return -1;
     }
-    if (_PyIOBase_check_writable(writer, Py_True) == NULL)
+    if (_PyIOBase_check_writable(state, writer, Py_True) == NULL) {
         return -1;
+    }
 
     self->reader = (buffered *) PyObject_CallFunction(
             (PyObject *)state->PyBufferedReader_Type,
@@ -2304,8 +2306,9 @@ _io_BufferedRandom___init___impl(buffered *self, PyObject *raw,
     if (_PyIOBase_check_readable(state, raw, Py_True) == NULL) {
         return -1;
     }
-    if (_PyIOBase_check_writable(raw, Py_True) == NULL)
+    if (_PyIOBase_check_writable(state, raw, Py_True) == NULL) {
         return -1;
+    }
 
     Py_INCREF(raw);
     Py_XSETREF(self->raw, raw);
diff --git a/Modules/_io/iobase.c b/Modules/_io/iobase.c
index fbafdbc48925b4..ca13866c33fba6 100644
--- a/Modules/_io/iobase.c
+++ b/Modules/_io/iobase.c
@@ -221,7 +221,8 @@ iobase_check_readable(PyObject *self, PyObject *args)
 static PyObject *
 iobase_check_writable(PyObject *self, PyObject *args)
 {
-    return _PyIOBase_check_writable(self, args);
+    _PyIO_State *state = IO_STATE();
+    return _PyIOBase_check_writable(state, self, args);
 }
 
 /* XXX: IOBase thinks it has to maintain its own internal state in
@@ -458,14 +459,13 @@ _io__IOBase_writable_impl(PyObject *self)
 
 /* May be called with any object */
 PyObject *
-_PyIOBase_check_writable(PyObject *self, PyObject *args)
+_PyIOBase_check_writable(_PyIO_State *state, PyObject *self, PyObject *args)
 {
     PyObject *res = PyObject_CallMethodNoArgs(self, &_Py_ID(writable));
     if (res == NULL)
         return NULL;
     if (res != Py_True) {
         Py_CLEAR(res);
-        _PyIO_State *state = IO_STATE();
         iobase_unsupported(state, "File or stream is not writable.");
         return NULL;
     }

From b22b41d7858ae234fd25ec7e86cee827688cfa7e Mon Sep 17 00:00:00 2001
From: "Erlend E. Aasland" <erlend.aasland@protonmail.com>
Date: Tue, 9 May 2023 22:50:51 +0200
Subject: [PATCH 10/12] Fetch state by module def in _io__Buffered_seek_impl()

---
 Modules/_io/bufferedio.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Modules/_io/bufferedio.c b/Modules/_io/bufferedio.c
index 98abf7e7345846..172fafe6db8a3d 100644
--- a/Modules/_io/bufferedio.c
+++ b/Modules/_io/bufferedio.c
@@ -1224,7 +1224,7 @@ _io__Buffered_seek_impl(buffered *self, PyObject *targetobj, int whence)
 
     CHECK_CLOSED(self, "seek of closed file")
 
-    _PyIO_State *state = IO_STATE();
+    _PyIO_State *state = find_io_state_by_def(Py_TYPE(self));
     if (_PyIOBase_check_seekable(state, self->raw, Py_True) == NULL) {
         return NULL;
     }

From 0044293b1a93f0e4adeb77f48dda0efa3c42c314 Mon Sep 17 00:00:00 2001
From: "Erlend E. Aasland" <erlend.aasland@protonmail.com>
Date: Wed, 10 May 2023 00:28:10 +0200
Subject: [PATCH 11/12] Address review: improve forward decl. of _PyIO_State

---
 Modules/_io/_iomodule.h | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/Modules/_io/_iomodule.h b/Modules/_io/_iomodule.h
index 5c6124eb88e21e..b11e5a1849d967 100644
--- a/Modules/_io/_iomodule.h
+++ b/Modules/_io/_iomodule.h
@@ -34,12 +34,12 @@ extern PyType_Spec winconsoleio_spec;
  * with args=NULL, and return a new reference.
  * BUT when args=Py_True is passed, they return a borrowed reference.
  */
-struct _io_state;  // Forward decl.
-extern PyObject* _PyIOBase_check_readable(struct _io_state *state,
+typedef struct _io_state _PyIO_State;  // Forward decl.
+extern PyObject* _PyIOBase_check_readable(_PyIO_State *state,
                                           PyObject *self, PyObject *args);
-extern PyObject* _PyIOBase_check_writable(struct _io_state *state,
+extern PyObject* _PyIOBase_check_writable(_PyIO_State *state,
                                           PyObject *self, PyObject *args);
-extern PyObject* _PyIOBase_check_seekable(struct _io_state *state,
+extern PyObject* _PyIOBase_check_seekable(_PyIO_State *state,
                                           PyObject *self, PyObject *args);
 extern PyObject* _PyIOBase_check_closed(PyObject *self, PyObject *args);
 

From 7aa8da76a45c237f80e86a4bd2d0542e8426e395 Mon Sep 17 00:00:00 2001
From: "Erlend E. Aasland" <erlend.aasland@protonmail.com>
Date: Wed, 10 May 2023 00:39:52 +0200
Subject: [PATCH 12/12] Address review: remove second typedef

It may provoke compiler warnings
---
 Modules/_io/_iomodule.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/Modules/_io/_iomodule.h b/Modules/_io/_iomodule.h
index b11e5a1849d967..b3873ddf7e0847 100644
--- a/Modules/_io/_iomodule.h
+++ b/Modules/_io/_iomodule.h
@@ -144,7 +144,7 @@ extern Py_off_t PyNumber_AsOff_t(PyObject *item, PyObject *err);
 
 extern PyModuleDef _PyIO_Module;
 
-typedef struct _io_state {
+struct _io_state {
     int initialized;
     PyObject *unsupported_operation;
 
@@ -165,7 +165,7 @@ typedef struct _io_state {
 #ifdef MS_WINDOWS
     PyTypeObject *PyWindowsConsoleIO_Type;
 #endif
-} _PyIO_State;
+};
 
 #define IO_MOD_STATE(mod) ((_PyIO_State *)PyModule_GetState(mod))
 #define IO_STATE() _PyIO_get_module_state()