From 2e28fb768576010250308d3cf273a700486151e2 Mon Sep 17 00:00:00 2001
From: Ken Jin <28750310+Fidget-Spinner@users.noreply.github.com>
Date: Mon, 3 Oct 2022 13:29:44 -0700
Subject: [PATCH 1/6] Cached co_* attrs

---
 Doc/c-api/code.rst          |  6 +--
 Include/cpython/code.h      |  9 ++++-
 Objects/codeobject.c        | 81 ++++++++++++++++++++++++++++++++-----
 Objects/frameobject.c       |  7 +++-
 Tools/scripts/deepfreeze.py |  2 +-
 5 files changed, 88 insertions(+), 17 deletions(-)

diff --git a/Doc/c-api/code.rst b/Doc/c-api/code.rst
index 9054e7ee3181a5..8c323965810f36 100644
--- a/Doc/c-api/code.rst
+++ b/Doc/c-api/code.rst
@@ -93,7 +93,7 @@ bound into a function.
 .. c:function:: PyObject* PyCode_GetVarnames(PyCodeObject *co)
 
    Equivalent to the Python code ``getattr(co, 'co_varnames')``.
-   Returns a new reference to a :c:type:`PyTupleObject` containing the names of
+   Returns a strong reference to a :c:type:`PyTupleObject` containing the names of
    the local variables. On error, ``NULL`` is returned and an exception
    is raised.
 
@@ -102,7 +102,7 @@ bound into a function.
 .. c:function:: PyObject* PyCode_GetCellvars(PyCodeObject *co)
 
    Equivalent to the Python code ``getattr(co, 'co_cellvars')``.
-   Returns a new reference to a :c:type:`PyTupleObject` containing the names of
+   Returns a strong reference to a :c:type:`PyTupleObject` containing the names of
    the local variables that are referenced by nested functions. On error, ``NULL``
    is returned and an exception is raised.
 
@@ -111,7 +111,7 @@ bound into a function.
 .. c:function:: PyObject* PyCode_GetFreevars(PyCodeObject *co)
 
    Equivalent to the Python code ``getattr(co, 'co_freevars')``.
-   Returns a new reference to a :c:type:`PyTupleObject` containing the names of
+   Returns a strong reference to a :c:type:`PyTupleObject` containing the names of
    the free variables. On error, ``NULL`` is returned and an exception is raised.
 
    .. versionadded:: 3.11
diff --git a/Include/cpython/code.h b/Include/cpython/code.h
index 7ce69022557af0..893ff934d3d879 100644
--- a/Include/cpython/code.h
+++ b/Include/cpython/code.h
@@ -32,6 +32,13 @@ typedef uint16_t _Py_CODEUNIT;
 #define _Py_SET_OPCODE(word, opcode) \
     do { ((unsigned char *)&(word))[0] = (opcode); } while (0)
 
+typedef struct {
+    PyObject *_co_code;
+    PyObject *_co_varnames;
+    PyObject *_co_cellvars;
+    PyObject *_co_freevars;
+} _PyCoCached;
+
 // To avoid repeating ourselves in deepfreeze.py, all PyCodeObject members are
 // defined in this macro:
 #define _PyCode_DEF(SIZE) {                                                    \
@@ -90,7 +97,7 @@ typedef uint16_t _Py_CODEUNIT;
     PyObject *co_qualname;        /* unicode (qualname, for reference) */      \
     PyObject *co_linetable;       /* bytes object that holds location info */  \
     PyObject *co_weakreflist;     /* to support weakrefs to code objects */    \
-    PyObject *_co_code;           /* cached co_code object/attribute */        \
+    _PyCoCached *_co_cached;      /* cached co_* attributes */                 \
     int _co_firsttraceable;       /* index of first traceable instruction */   \
     char *_co_linearray;          /* array of line offsets */                  \
     /* Scratch space for extra data relating to the code object.               \
diff --git a/Objects/codeobject.c b/Objects/codeobject.c
index 7d0d038f489a98..bc1b00c59de85b 100644
--- a/Objects/codeobject.c
+++ b/Objects/codeobject.c
@@ -150,7 +150,22 @@ validate_and_copy_tuple(PyObject *tup)
     return newtuple;
 }
 
+static int
+init_co_cached(PyCodeObject *self) {
+    if (self->_co_cached == NULL) {
+        self->_co_cached = PyMem_New(_PyCoCached, 1);
+        if (self->_co_cached == NULL) {
+            PyErr_NoMemory();
+            return 1;
+        }
+        self->_co_cached->_co_code = NULL;
+        self->_co_cached->_co_cellvars = NULL;
+        self->_co_cached->_co_freevars = NULL;
+        self->_co_cached->_co_varnames = NULL;
+    }
+    return 0;
 
+}
 /******************
  * _PyCode_New()
  ******************/
@@ -336,7 +351,7 @@ init_code(PyCodeObject *co, struct _PyCodeConstructor *con)
     /* not set */
     co->co_weakreflist = NULL;
     co->co_extra = NULL;
-    co->_co_code = NULL;
+    co->_co_cached = NULL;
 
     co->co_warmup = QUICKENING_INITIAL_WARMUP_VALUE;
     co->_co_linearray_entry_size = 0;
@@ -1371,7 +1386,20 @@ _PyCode_SetExtra(PyObject *code, Py_ssize_t index, void *extra)
 PyObject *
 _PyCode_GetVarnames(PyCodeObject *co)
 {
-    return get_localsplus_names(co, CO_FAST_LOCAL, co->co_nlocals);
+    if (init_co_cached(co)) {
+        return NULL;
+    }
+    if (co->_co_cached->_co_varnames != NULL) {
+        return Py_NewRef(co->_co_cached->_co_varnames);
+    }
+    assert(co->_co_cached->_co_varnames == NULL);
+    PyObject *varnames = get_localsplus_names(co, CO_FAST_LOCAL, co->co_nlocals);
+    if (varnames == NULL) {
+        return NULL;
+    }
+    co->_co_cached->_co_varnames = Py_NewRef(varnames);
+    return varnames;
+
 }
 
 PyObject *
@@ -1383,7 +1411,16 @@ PyCode_GetVarnames(PyCodeObject *code)
 PyObject *
 _PyCode_GetCellvars(PyCodeObject *co)
 {
-    return get_localsplus_names(co, CO_FAST_CELL, co->co_ncellvars);
+    if (init_co_cached(co)) {
+        return NULL;
+    }
+    if (co->_co_cached->_co_cellvars != NULL) {
+        return Py_NewRef(co->_co_cached->_co_cellvars);
+    }
+    PyObject *cellvars = get_localsplus_names(co, CO_FAST_CELL, co->co_ncellvars);
+    assert(co->_co_cached->_co_cellvars == NULL);
+    co->_co_cached->_co_cellvars = Py_NewRef(cellvars);
+    return cellvars;
 }
 
 PyObject *
@@ -1395,7 +1432,16 @@ PyCode_GetCellvars(PyCodeObject *code)
 PyObject *
 _PyCode_GetFreevars(PyCodeObject *co)
 {
-    return get_localsplus_names(co, CO_FAST_FREE, co->co_nfreevars);
+    if (init_co_cached(co)) {
+        return NULL;
+    }
+    if (co->_co_cached->_co_freevars != NULL) {
+        return Py_NewRef(co->_co_cached->_co_freevars);
+    }
+    PyObject *freevars = get_localsplus_names(co, CO_FAST_FREE, co->co_nfreevars);
+    assert(co->_co_cached->_co_freevars == NULL);
+    co->_co_cached->_co_freevars = Py_NewRef(freevars);
+    return freevars;
 }
 
 PyObject *
@@ -1421,8 +1467,11 @@ deopt_code(_Py_CODEUNIT *instructions, Py_ssize_t len)
 PyObject *
 _PyCode_GetCode(PyCodeObject *co)
 {
-    if (co->_co_code != NULL) {
-        return Py_NewRef(co->_co_code);
+    if (init_co_cached(co)) {
+        return NULL;
+    }
+    if (co->_co_cached->_co_code != NULL) {
+        return Py_NewRef(co->_co_cached->_co_code);
     }
     PyObject *code = PyBytes_FromStringAndSize((const char *)_PyCode_CODE(co),
                                                _PyCode_NBYTES(co));
@@ -1430,8 +1479,8 @@ _PyCode_GetCode(PyCodeObject *co)
         return NULL;
     }
     deopt_code((_Py_CODEUNIT *)PyBytes_AS_STRING(code), Py_SIZE(co));
-    assert(co->_co_code == NULL);
-    co->_co_code = Py_NewRef(code);
+    assert(co->_co_cached->_co_code == NULL);
+    co->_co_cached->_co_code = Py_NewRef(code);
     return code;
 }
 
@@ -1590,7 +1639,13 @@ code_dealloc(PyCodeObject *co)
     Py_XDECREF(co->co_qualname);
     Py_XDECREF(co->co_linetable);
     Py_XDECREF(co->co_exceptiontable);
-    Py_XDECREF(co->_co_code);
+    if (co->_co_cached != NULL) {
+        Py_XDECREF(co->_co_cached->_co_code);
+        Py_XDECREF(co->_co_cached->_co_cellvars);
+        Py_XDECREF(co->_co_cached->_co_freevars);
+        Py_XDECREF(co->_co_cached->_co_varnames);
+        PyMem_Free(co->_co_cached);
+    }
     if (co->co_weakreflist != NULL) {
         PyObject_ClearWeakRefs((PyObject*)co);
     }
@@ -2165,7 +2220,13 @@ _PyStaticCode_Dealloc(PyCodeObject *co)
     deopt_code(_PyCode_CODE(co), Py_SIZE(co));
     co->co_warmup = QUICKENING_INITIAL_WARMUP_VALUE;
     PyMem_Free(co->co_extra);
-    Py_CLEAR(co->_co_code);
+    if (co->_co_cached != NULL) {
+        Py_CLEAR(co->_co_cached->_co_code);
+        Py_CLEAR(co->_co_cached->_co_cellvars);
+        Py_CLEAR(co->_co_cached->_co_freevars);
+        Py_CLEAR(co->_co_cached->_co_varnames);
+        PyMem_Free(co->_co_cached);
+    }
     co->co_extra = NULL;
     if (co->co_weakreflist != NULL) {
         PyObject_ClearWeakRefs((PyObject *)co);
diff --git a/Objects/frameobject.c b/Objects/frameobject.c
index 2e377794312612..9912204782cf29 100644
--- a/Objects/frameobject.c
+++ b/Objects/frameobject.c
@@ -644,9 +644,12 @@ add_load_fast_null_checks(PyCodeObject *co)
         }
         i += _PyOpcode_Caches[_PyOpcode_Deopt[opcode]];
     }
-    if (changed) {
+    if (changed && co->_co_cached != NULL) {
         // invalidate cached co_code object
-        Py_CLEAR(co->_co_code);
+        Py_CLEAR(co->_co_cached->_co_code);
+        Py_CLEAR(co->_co_cached->_co_cellvars);
+        Py_CLEAR(co->_co_cached->_co_freevars);
+        Py_CLEAR(co->_co_cached->_co_varnames);
     }
 }
 
diff --git a/Tools/scripts/deepfreeze.py b/Tools/scripts/deepfreeze.py
index d9c6030fc17c07..28ac2b12f92fa7 100644
--- a/Tools/scripts/deepfreeze.py
+++ b/Tools/scripts/deepfreeze.py
@@ -276,7 +276,7 @@ def generate_code(self, name: str, code: types.CodeType) -> str:
             self.write(f".co_name = {co_name},")
             self.write(f".co_qualname = {co_qualname},")
             self.write(f".co_linetable = {co_linetable},")
-            self.write(f"._co_code = NULL,")
+            self.write(f"._co_cached = NULL,")
             self.write("._co_linearray = NULL,")
             self.write(f".co_code_adaptive = {co_code_adaptive},")
             for i, op in enumerate(code.co_code[::2]):

From 4e85e31660f6bee5dd1ca96efb7b43f3c567684f Mon Sep 17 00:00:00 2001
From: "blurb-it[bot]" <43283697+blurb-it[bot]@users.noreply.github.com>
Date: Mon, 3 Oct 2022 20:33:25 +0000
Subject: [PATCH 2/6] =?UTF-8?q?=F0=9F=93=9C=F0=9F=A4=96=20Added=20by=20blu?=
 =?UTF-8?q?rb=5Fit.?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .../next/C API/2022-10-03-20-33-24.gh-issue-95756.SSmXlG.rst     | 1 +
 1 file changed, 1 insertion(+)
 create mode 100644 Misc/NEWS.d/next/C API/2022-10-03-20-33-24.gh-issue-95756.SSmXlG.rst

diff --git a/Misc/NEWS.d/next/C API/2022-10-03-20-33-24.gh-issue-95756.SSmXlG.rst b/Misc/NEWS.d/next/C API/2022-10-03-20-33-24.gh-issue-95756.SSmXlG.rst
new file mode 100644
index 00000000000000..bec44339d851a7
--- /dev/null
+++ b/Misc/NEWS.d/next/C API/2022-10-03-20-33-24.gh-issue-95756.SSmXlG.rst	
@@ -0,0 +1 @@
+Lazily create and cache ``co_*`` attributes for better performance for code getters.

From 6cfa7aed2c9d0a4e5f5b415a8735a525f26d1a3b Mon Sep 17 00:00:00 2001
From: Ken Jin <28750310+Fidget-Spinner@users.noreply.github.com>
Date: Fri, 7 Oct 2022 12:17:18 -0700
Subject: [PATCH 3/6] apply suggestions

---
 Doc/c-api/code.rst   |  6 +++---
 Objects/codeobject.c | 44 ++++++++++++++++----------------------------
 2 files changed, 19 insertions(+), 31 deletions(-)

diff --git a/Doc/c-api/code.rst b/Doc/c-api/code.rst
index 8c323965810f36..9054e7ee3181a5 100644
--- a/Doc/c-api/code.rst
+++ b/Doc/c-api/code.rst
@@ -93,7 +93,7 @@ bound into a function.
 .. c:function:: PyObject* PyCode_GetVarnames(PyCodeObject *co)
 
    Equivalent to the Python code ``getattr(co, 'co_varnames')``.
-   Returns a strong reference to a :c:type:`PyTupleObject` containing the names of
+   Returns a new reference to a :c:type:`PyTupleObject` containing the names of
    the local variables. On error, ``NULL`` is returned and an exception
    is raised.
 
@@ -102,7 +102,7 @@ bound into a function.
 .. c:function:: PyObject* PyCode_GetCellvars(PyCodeObject *co)
 
    Equivalent to the Python code ``getattr(co, 'co_cellvars')``.
-   Returns a strong reference to a :c:type:`PyTupleObject` containing the names of
+   Returns a new reference to a :c:type:`PyTupleObject` containing the names of
    the local variables that are referenced by nested functions. On error, ``NULL``
    is returned and an exception is raised.
 
@@ -111,7 +111,7 @@ bound into a function.
 .. c:function:: PyObject* PyCode_GetFreevars(PyCodeObject *co)
 
    Equivalent to the Python code ``getattr(co, 'co_freevars')``.
-   Returns a strong reference to a :c:type:`PyTupleObject` containing the names of
+   Returns a new reference to a :c:type:`PyTupleObject` containing the names of
    the free variables. On error, ``NULL`` is returned and an exception is raised.
 
    .. versionadded:: 3.11
diff --git a/Objects/codeobject.c b/Objects/codeobject.c
index bc1b00c59de85b..5a18f3f40345de 100644
--- a/Objects/codeobject.c
+++ b/Objects/codeobject.c
@@ -156,7 +156,7 @@ init_co_cached(PyCodeObject *self) {
         self->_co_cached = PyMem_New(_PyCoCached, 1);
         if (self->_co_cached == NULL) {
             PyErr_NoMemory();
-            return 1;
+            return -1;
         }
         self->_co_cached->_co_code = NULL;
         self->_co_cached->_co_cellvars = NULL;
@@ -1383,23 +1383,29 @@ _PyCode_SetExtra(PyObject *code, Py_ssize_t index, void *extra)
  * other PyCodeObject accessor functions
  ******************/
 
-PyObject *
-_PyCode_GetVarnames(PyCodeObject *co)
+static PyObject *
+get_cached_locals(PyCodeObject *co, PyObject **cached_field, _PyLocals_Kind kind, int num)
 {
+    assert(cached_field != NULL);
     if (init_co_cached(co)) {
         return NULL;
     }
-    if (co->_co_cached->_co_varnames != NULL) {
-        return Py_NewRef(co->_co_cached->_co_varnames);
+    if (*cached_field != NULL) {
+        return Py_NewRef(*cached_field);
     }
-    assert(co->_co_cached->_co_varnames == NULL);
-    PyObject *varnames = get_localsplus_names(co, CO_FAST_LOCAL, co->co_nlocals);
+    assert(*cached_field == NULL);
+    PyObject *varnames = get_localsplus_names(co, kind, num);
     if (varnames == NULL) {
         return NULL;
     }
-    co->_co_cached->_co_varnames = Py_NewRef(varnames);
+    *cached_field = Py_NewRef(varnames);
     return varnames;
+}
 
+PyObject *
+_PyCode_GetVarnames(PyCodeObject *co)
+{
+    return get_cached_locals(co, &co->_co_cached->_co_varnames, CO_FAST_LOCAL, co->co_nlocals);
 }
 
 PyObject *
@@ -1411,16 +1417,7 @@ PyCode_GetVarnames(PyCodeObject *code)
 PyObject *
 _PyCode_GetCellvars(PyCodeObject *co)
 {
-    if (init_co_cached(co)) {
-        return NULL;
-    }
-    if (co->_co_cached->_co_cellvars != NULL) {
-        return Py_NewRef(co->_co_cached->_co_cellvars);
-    }
-    PyObject *cellvars = get_localsplus_names(co, CO_FAST_CELL, co->co_ncellvars);
-    assert(co->_co_cached->_co_cellvars == NULL);
-    co->_co_cached->_co_cellvars = Py_NewRef(cellvars);
-    return cellvars;
+    return get_cached_locals(co, &co->_co_cached->_co_cellvars, CO_FAST_CELL, co->co_ncellvars);
 }
 
 PyObject *
@@ -1432,16 +1429,7 @@ PyCode_GetCellvars(PyCodeObject *code)
 PyObject *
 _PyCode_GetFreevars(PyCodeObject *co)
 {
-    if (init_co_cached(co)) {
-        return NULL;
-    }
-    if (co->_co_cached->_co_freevars != NULL) {
-        return Py_NewRef(co->_co_cached->_co_freevars);
-    }
-    PyObject *freevars = get_localsplus_names(co, CO_FAST_FREE, co->co_nfreevars);
-    assert(co->_co_cached->_co_freevars == NULL);
-    co->_co_cached->_co_freevars = Py_NewRef(freevars);
-    return freevars;
+    return get_cached_locals(co, &co->_co_cached->_co_freevars, CO_FAST_FREE, co->co_nfreevars);
 }
 
 PyObject *

From ce5f0e874de41023cbae89b883f8c938785e10a3 Mon Sep 17 00:00:00 2001
From: Ken Jin <28750310+Fidget-Spinner@users.noreply.github.com>
Date: Fri, 7 Oct 2022 13:40:44 -0700
Subject: [PATCH 4/6] fix segfault

---
 Objects/codeobject.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/Objects/codeobject.c b/Objects/codeobject.c
index 5a18f3f40345de..01f38f8b558524 100644
--- a/Objects/codeobject.c
+++ b/Objects/codeobject.c
@@ -1387,9 +1387,7 @@ static PyObject *
 get_cached_locals(PyCodeObject *co, PyObject **cached_field, _PyLocals_Kind kind, int num)
 {
     assert(cached_field != NULL);
-    if (init_co_cached(co)) {
-        return NULL;
-    }
+    assert(co->_co_cached != NULL);
     if (*cached_field != NULL) {
         return Py_NewRef(*cached_field);
     }
@@ -1405,6 +1403,9 @@ get_cached_locals(PyCodeObject *co, PyObject **cached_field, _PyLocals_Kind kind
 PyObject *
 _PyCode_GetVarnames(PyCodeObject *co)
 {
+    if (init_co_cached(co)) {
+        return NULL;
+    }
     return get_cached_locals(co, &co->_co_cached->_co_varnames, CO_FAST_LOCAL, co->co_nlocals);
 }
 
@@ -1417,6 +1418,9 @@ PyCode_GetVarnames(PyCodeObject *code)
 PyObject *
 _PyCode_GetCellvars(PyCodeObject *co)
 {
+    if (init_co_cached(co)) {
+        return NULL;
+    }
     return get_cached_locals(co, &co->_co_cached->_co_cellvars, CO_FAST_CELL, co->co_ncellvars);
 }
 
@@ -1429,6 +1433,9 @@ PyCode_GetCellvars(PyCodeObject *code)
 PyObject *
 _PyCode_GetFreevars(PyCodeObject *co)
 {
+    if (init_co_cached(co)) {
+        return NULL;
+    }
     return get_cached_locals(co, &co->_co_cached->_co_freevars, CO_FAST_FREE, co->co_nfreevars);
 }
 

From d998aa14bc8c89dd9fef2d34d942510793846cfe Mon Sep 17 00:00:00 2001
From: Ken Jin <28750310+Fidget-Spinner@users.noreply.github.com>
Date: Fri, 7 Oct 2022 14:38:16 -0700
Subject: [PATCH 5/6] yes

---
 Objects/codeobject.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/Objects/codeobject.c b/Objects/codeobject.c
index 01f38f8b558524..73e33551ef5249 100644
--- a/Objects/codeobject.c
+++ b/Objects/codeobject.c
@@ -1384,7 +1384,8 @@ _PyCode_SetExtra(PyObject *code, Py_ssize_t index, void *extra)
  ******************/
 
 static PyObject *
-get_cached_locals(PyCodeObject *co, PyObject **cached_field, _PyLocals_Kind kind, int num)
+get_cached_locals(PyCodeObject *co, PyObject **cached_field,
+    _PyLocals_Kind kind, int num)
 {
     assert(cached_field != NULL);
     assert(co->_co_cached != NULL);

From d321cfb923cc9dc0f02c9f646e6963a4e5e756ae Mon Sep 17 00:00:00 2001
From: Ken Jin <28750310+Fidget-Spinner@users.noreply.github.com>
Date: Fri, 7 Oct 2022 16:00:20 -0700
Subject: [PATCH 6/6] Update 2022-10-03-20-33-24.gh-issue-95756.SSmXlG.rst

---
 .../next/C API/2022-10-03-20-33-24.gh-issue-95756.SSmXlG.rst    | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Misc/NEWS.d/next/C API/2022-10-03-20-33-24.gh-issue-95756.SSmXlG.rst b/Misc/NEWS.d/next/C API/2022-10-03-20-33-24.gh-issue-95756.SSmXlG.rst
index bec44339d851a7..b5c78c16e86d18 100644
--- a/Misc/NEWS.d/next/C API/2022-10-03-20-33-24.gh-issue-95756.SSmXlG.rst	
+++ b/Misc/NEWS.d/next/C API/2022-10-03-20-33-24.gh-issue-95756.SSmXlG.rst	
@@ -1 +1 @@
-Lazily create and cache ``co_*`` attributes for better performance for code getters.
+Lazily create and cache ``co_`` attributes for better performance for code getters.