Add the co_extra field and accompanying APIs to code objects.

This completes PEP 523.
This commit is contained in:
Brett Cannon 2016-09-07 11:16:41 -07:00
parent a9296e7f3b
commit 5c4de2863b
8 changed files with 139 additions and 3 deletions

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@ -127,7 +127,8 @@ evaluation, etc.
This API is not part of the limited C API and is marked as private to
signal that usage of this API is expected to be limited and only
applicable to very select, low-level use-cases.
applicable to very select, low-level use-cases. Semantics of the
API will change with Python as necessary.
.. seealso::

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@ -187,6 +187,10 @@ PyAPI_FUNC(void) _PyEval_SetSwitchInterval(unsigned long microseconds);
PyAPI_FUNC(unsigned long) _PyEval_GetSwitchInterval(void);
#endif
#ifndef Py_LIMITED_API
PyAPI_FUNC(Py_ssize_t) _PyEval_RequestCodeExtraIndex(freefunc);
#endif
#define Py_BEGIN_ALLOW_THREADS { \
PyThreadState *_save; \
_save = PyEval_SaveThread();

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@ -7,6 +7,14 @@
extern "C" {
#endif
/* Holder for co_extra information */
typedef struct {
Py_ssize_t ce_size;
void **ce_extras;
} _PyCodeObjectExtra;
/* Bytecode object */
typedef struct {
PyObject_HEAD
@ -15,6 +23,7 @@ typedef struct {
int co_nlocals; /* #local variables */
int co_stacksize; /* #entries needed for evaluation stack */
int co_flags; /* CO_..., see below */
int co_firstlineno; /* first source line number */
PyObject *co_code; /* instruction opcodes */
PyObject *co_consts; /* list (constants used) */
PyObject *co_names; /* list of strings (names used) */
@ -30,11 +39,12 @@ typedef struct {
unsigned char *co_cell2arg; /* Maps cell vars which are arguments. */
PyObject *co_filename; /* unicode (where it was loaded from) */
PyObject *co_name; /* unicode (name, for reference) */
int co_firstlineno; /* first source line number */
PyObject *co_lnotab; /* string (encoding addr<->lineno mapping) See
Objects/lnotab_notes.txt for details. */
void *co_zombieframe; /* for optimization only (see frameobject.c) */
PyObject *co_weakreflist; /* to support weakrefs to code objects */
/* Scratch space for extra data relating to the code object */
_PyCodeObjectExtra *co_extra;
} PyCodeObject;
/* Masks for co_flags above */
@ -128,6 +138,14 @@ PyAPI_FUNC(PyObject*) _PyCode_ConstantKey(PyObject *obj);
PyAPI_FUNC(PyObject*) PyCode_Optimize(PyObject *code, PyObject* consts,
PyObject *names, PyObject *lnotab);
#ifndef Py_LIMITED_API
PyAPI_FUNC(int) _PyCode_GetExtra(PyObject *code, Py_ssize_t index,
void **extra);
PyAPI_FUNC(int) _PyCode_SetExtra(PyObject *code, Py_ssize_t index,
void *extra);
#endif
#ifdef __cplusplus
}
#endif

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@ -8,6 +8,10 @@
extern "C" {
#endif
/* This limitation is for performance and simplicity. If needed it can be
removed (with effort). */
#define MAX_CO_EXTRA_USERS 255
/* State shared between threads */
struct _ts; /* Forward */
@ -141,6 +145,9 @@ typedef struct _ts {
PyObject *coroutine_wrapper;
int in_coroutine_wrapper;
Py_ssize_t co_extra_user_count;
freefunc co_extra_freefuncs[MAX_CO_EXTRA_USERS];
/* XXX signal handlers should also be here */
} PyThreadState;

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@ -27,7 +27,7 @@ Core and Builtins
the braces (where the expressions are). This is a breaking change
from the 3.6 alpha releases.
- Implement the frame evaluation part of PEP 523.
- Implement PEP 523.
- Issue #27870: A left shift of zero by a large integer no longer attempts
to allocate large amounts of memory.

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@ -152,6 +152,7 @@ PyCode_New(int argcount, int kwonlyargcount,
co->co_lnotab = lnotab;
co->co_zombieframe = NULL;
co->co_weakreflist = NULL;
co->co_extra = NULL;
return co;
}
@ -361,6 +362,20 @@ code_new(PyTypeObject *type, PyObject *args, PyObject *kw)
static void
code_dealloc(PyCodeObject *co)
{
if (co->co_extra != NULL) {
PyThreadState *tstate = PyThreadState_Get();
for (Py_ssize_t i = 0; i < co->co_extra->ce_size; i++) {
freefunc free_extra = tstate->co_extra_freefuncs[i];
if (free_extra != NULL) {
free_extra(co->co_extra->ce_extras[i]);
}
}
PyMem_FREE(co->co_extra);
}
Py_XDECREF(co->co_code);
Py_XDECREF(co->co_consts);
Py_XDECREF(co->co_names);
@ -752,3 +767,79 @@ _PyCode_CheckLineNumber(PyCodeObject* co, int lasti, PyAddrPair *bounds)
return line;
}
int
_PyCode_GetExtra(PyObject *code, Py_ssize_t index, void **extra)
{
PyCodeObject *o;
assert(*extra == NULL);
if (!PyCode_Check(code)) {
PyErr_BadInternalCall();
return 1;
}
o = (PyCodeObject*) code;
if (o->co_extra == NULL || o->co_extra->ce_size <= index) {
return 0;
}
*extra = o->co_extra->ce_extras[index];
return 0;
}
int
_PyCode_SetExtra(PyObject *code, Py_ssize_t index, void *extra)
{
PyCodeObject *o;
PyThreadState *tstate = PyThreadState_Get();
if (!PyCode_Check(code) || index < 0 ||
index >= tstate->co_extra_user_count) {
PyErr_BadInternalCall();
return 1;
}
o = (PyCodeObject*) code;
if (o->co_extra == NULL) {
o->co_extra = (_PyCodeObjectExtra*) PyMem_Malloc(
sizeof(_PyCodeObjectExtra));
if (o->co_extra == NULL) {
return 1;
}
o->co_extra->ce_extras = PyMem_Malloc(
tstate->co_extra_user_count * sizeof(void*));
if (o->co_extra->ce_extras == NULL) {
return 1;
}
o->co_extra->ce_size = tstate->co_extra_user_count;
for (Py_ssize_t i = 0; i < o->co_extra->ce_size; i++) {
o->co_extra->ce_extras[i] = NULL;
}
}
else if (o->co_extra->ce_size <= index) {
o->co_extra->ce_extras = PyMem_Realloc(
o->co_extra->ce_extras, tstate->co_extra_user_count * sizeof(void*));
if (o->co_extra->ce_extras == NULL) {
return 1;
}
o->co_extra->ce_size = tstate->co_extra_user_count;
for (Py_ssize_t i = o->co_extra->ce_size; i < o->co_extra->ce_size; i++) {
o->co_extra->ce_extras[i] = NULL;
}
}
o->co_extra->ce_extras[index] = extra;
return 0;
}

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@ -5608,3 +5608,17 @@ _Py_GetDXProfile(PyObject *self, PyObject *args)
}
#endif
Py_ssize_t
_PyEval_RequestCodeExtraIndex(freefunc free)
{
PyThreadState *tstate = PyThreadState_Get();
Py_ssize_t new_index;
if (tstate->co_extra_user_count == MAX_CO_EXTRA_USERS - 1) {
return -1;
}
new_index = tstate->co_extra_user_count++;
tstate->co_extra_freefuncs[new_index] = free;
return new_index;
}

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@ -227,6 +227,7 @@ new_threadstate(PyInterpreterState *interp, int init)
tstate->coroutine_wrapper = NULL;
tstate->in_coroutine_wrapper = 0;
tstate->co_extra_user_count = 0;
if (init)
_PyThreadState_Init(tstate);