mirror of https://github.com/python/cpython
275 lines
8.2 KiB
C
275 lines
8.2 KiB
C
#ifndef Py_INTERNAL_STACKREF_H
|
|
#define Py_INTERNAL_STACKREF_H
|
|
#ifdef __cplusplus
|
|
extern "C" {
|
|
#endif
|
|
|
|
#ifndef Py_BUILD_CORE
|
|
# error "this header requires Py_BUILD_CORE define"
|
|
#endif
|
|
|
|
#include "pycore_object_deferred.h"
|
|
|
|
#include <stddef.h>
|
|
#include <stdbool.h>
|
|
|
|
/*
|
|
This file introduces a new API for handling references on the stack, called
|
|
_PyStackRef. This API is inspired by HPy.
|
|
|
|
There are 3 main operations, that convert _PyStackRef to PyObject* and
|
|
vice versa:
|
|
|
|
1. Borrow (discouraged)
|
|
2. Steal
|
|
3. New
|
|
|
|
Borrow means that the reference is converted without any change in ownership.
|
|
This is discouraged because it makes verification much harder. It also makes
|
|
unboxed integers harder in the future.
|
|
|
|
Steal means that ownership is transferred to something else. The total
|
|
number of references to the object stays the same.
|
|
|
|
New creates a new reference from the old reference. The old reference
|
|
is still valid.
|
|
|
|
With these 3 API, a strict stack discipline must be maintained. All
|
|
_PyStackRef must be operated on by the new reference operations:
|
|
|
|
1. DUP
|
|
2. CLOSE
|
|
|
|
DUP is roughly equivalent to Py_NewRef. It creates a new reference from an old
|
|
reference. The old reference remains unchanged.
|
|
|
|
CLOSE is roughly equivalent to Py_DECREF. It destroys a reference.
|
|
|
|
Note that it is unsafe to borrow a _PyStackRef and then do normal
|
|
CPython refcounting operations on it!
|
|
*/
|
|
|
|
typedef union _PyStackRef {
|
|
uintptr_t bits;
|
|
} _PyStackRef;
|
|
|
|
|
|
#define Py_TAG_DEFERRED (1)
|
|
|
|
#define Py_TAG_PTR (0)
|
|
#define Py_TAG_BITS (1)
|
|
|
|
#ifdef Py_GIL_DISABLED
|
|
static const _PyStackRef PyStackRef_NULL = { .bits = 0 | Py_TAG_DEFERRED};
|
|
#else
|
|
static const _PyStackRef PyStackRef_NULL = { .bits = 0 };
|
|
#endif
|
|
|
|
#define PyStackRef_IsNull(stackref) ((stackref).bits == PyStackRef_NULL.bits)
|
|
|
|
|
|
#ifdef Py_GIL_DISABLED
|
|
# define PyStackRef_True ((_PyStackRef){.bits = ((uintptr_t)&_Py_TrueStruct) | Py_TAG_DEFERRED })
|
|
#else
|
|
# define PyStackRef_True ((_PyStackRef){.bits = ((uintptr_t)&_Py_TrueStruct) })
|
|
#endif
|
|
|
|
#ifdef Py_GIL_DISABLED
|
|
# define PyStackRef_False ((_PyStackRef){.bits = ((uintptr_t)&_Py_FalseStruct) | Py_TAG_DEFERRED })
|
|
#else
|
|
# define PyStackRef_False ((_PyStackRef){.bits = ((uintptr_t)&_Py_FalseStruct) })
|
|
#endif
|
|
|
|
#ifdef Py_GIL_DISABLED
|
|
# define PyStackRef_None ((_PyStackRef){.bits = ((uintptr_t)&_Py_NoneStruct) | Py_TAG_DEFERRED })
|
|
#else
|
|
# define PyStackRef_None ((_PyStackRef){.bits = ((uintptr_t)&_Py_NoneStruct) })
|
|
#endif
|
|
|
|
// Note: the following are all macros because MSVC (Windows) has trouble inlining them.
|
|
|
|
#define PyStackRef_Is(a, b) ((a).bits == (b).bits)
|
|
|
|
#define PyStackRef_IsDeferred(ref) (((ref).bits & Py_TAG_BITS) == Py_TAG_DEFERRED)
|
|
|
|
|
|
#ifdef Py_GIL_DISABLED
|
|
// Gets a PyObject * from a _PyStackRef
|
|
static inline PyObject *
|
|
PyStackRef_AsPyObjectBorrow(_PyStackRef stackref)
|
|
{
|
|
PyObject *cleared = ((PyObject *)((stackref).bits & (~Py_TAG_BITS)));
|
|
return cleared;
|
|
}
|
|
#else
|
|
# define PyStackRef_AsPyObjectBorrow(stackref) ((PyObject *)(stackref).bits)
|
|
#endif
|
|
|
|
// Converts a PyStackRef back to a PyObject *, stealing the
|
|
// PyStackRef.
|
|
#ifdef Py_GIL_DISABLED
|
|
static inline PyObject *
|
|
PyStackRef_AsPyObjectSteal(_PyStackRef stackref)
|
|
{
|
|
if (!PyStackRef_IsNull(stackref) && PyStackRef_IsDeferred(stackref)) {
|
|
return Py_NewRef(PyStackRef_AsPyObjectBorrow(stackref));
|
|
}
|
|
return PyStackRef_AsPyObjectBorrow(stackref);
|
|
}
|
|
#else
|
|
# define PyStackRef_AsPyObjectSteal(stackref) PyStackRef_AsPyObjectBorrow(stackref)
|
|
#endif
|
|
|
|
// Converts a PyStackRef back to a PyObject *, converting the
|
|
// stackref to a new reference.
|
|
#define PyStackRef_AsPyObjectNew(stackref) Py_NewRef(PyStackRef_AsPyObjectBorrow(stackref))
|
|
|
|
#define PyStackRef_TYPE(stackref) Py_TYPE(PyStackRef_AsPyObjectBorrow(stackref))
|
|
|
|
// Converts a PyObject * to a PyStackRef, stealing the reference
|
|
#ifdef Py_GIL_DISABLED
|
|
static inline _PyStackRef
|
|
_PyStackRef_FromPyObjectSteal(PyObject *obj)
|
|
{
|
|
// Make sure we don't take an already tagged value.
|
|
assert(((uintptr_t)obj & Py_TAG_BITS) == 0);
|
|
int tag = (obj == NULL || _Py_IsImmortal(obj)) ? (Py_TAG_DEFERRED) : Py_TAG_PTR;
|
|
return ((_PyStackRef){.bits = ((uintptr_t)(obj)) | tag});
|
|
}
|
|
# define PyStackRef_FromPyObjectSteal(obj) _PyStackRef_FromPyObjectSteal(_PyObject_CAST(obj))
|
|
#else
|
|
# define PyStackRef_FromPyObjectSteal(obj) ((_PyStackRef){.bits = ((uintptr_t)(obj))})
|
|
#endif
|
|
|
|
|
|
// Converts a PyObject * to a PyStackRef, with a new reference
|
|
#ifdef Py_GIL_DISABLED
|
|
static inline _PyStackRef
|
|
PyStackRef_FromPyObjectNew(PyObject *obj)
|
|
{
|
|
// Make sure we don't take an already tagged value.
|
|
assert(((uintptr_t)obj & Py_TAG_BITS) == 0);
|
|
assert(obj != NULL);
|
|
if (_Py_IsImmortal(obj) || _PyObject_HasDeferredRefcount(obj)) {
|
|
return (_PyStackRef){ .bits = (uintptr_t)obj | Py_TAG_DEFERRED };
|
|
}
|
|
else {
|
|
return (_PyStackRef){ .bits = (uintptr_t)(Py_NewRef(obj)) | Py_TAG_PTR };
|
|
}
|
|
}
|
|
# define PyStackRef_FromPyObjectNew(obj) PyStackRef_FromPyObjectNew(_PyObject_CAST(obj))
|
|
#else
|
|
# define PyStackRef_FromPyObjectNew(obj) ((_PyStackRef){ .bits = (uintptr_t)(Py_NewRef(obj)) })
|
|
#endif
|
|
|
|
#ifdef Py_GIL_DISABLED
|
|
// Same as PyStackRef_FromPyObjectNew but only for immortal objects.
|
|
static inline _PyStackRef
|
|
PyStackRef_FromPyObjectImmortal(PyObject *obj)
|
|
{
|
|
// Make sure we don't take an already tagged value.
|
|
assert(((uintptr_t)obj & Py_TAG_BITS) == 0);
|
|
assert(obj != NULL);
|
|
assert(_Py_IsImmortal(obj));
|
|
return (_PyStackRef){ .bits = (uintptr_t)obj | Py_TAG_DEFERRED };
|
|
}
|
|
# define PyStackRef_FromPyObjectImmortal(obj) PyStackRef_FromPyObjectImmortal(_PyObject_CAST(obj))
|
|
#else
|
|
# define PyStackRef_FromPyObjectImmortal(obj) ((_PyStackRef){ .bits = (uintptr_t)(obj) })
|
|
#endif
|
|
|
|
|
|
#define PyStackRef_CLEAR(op) \
|
|
do { \
|
|
_PyStackRef *_tmp_op_ptr = &(op); \
|
|
_PyStackRef _tmp_old_op = (*_tmp_op_ptr); \
|
|
if (!PyStackRef_IsNull(_tmp_old_op)) { \
|
|
*_tmp_op_ptr = PyStackRef_NULL; \
|
|
PyStackRef_CLOSE(_tmp_old_op); \
|
|
} \
|
|
} while (0)
|
|
|
|
#ifdef Py_GIL_DISABLED
|
|
# define PyStackRef_CLOSE(REF) \
|
|
do { \
|
|
_PyStackRef _close_tmp = (REF); \
|
|
if (!PyStackRef_IsDeferred(_close_tmp)) { \
|
|
Py_DECREF(PyStackRef_AsPyObjectBorrow(_close_tmp)); \
|
|
} \
|
|
} while (0)
|
|
#else
|
|
# define PyStackRef_CLOSE(stackref) Py_DECREF(PyStackRef_AsPyObjectBorrow(stackref))
|
|
#endif
|
|
|
|
#define PyStackRef_XCLOSE(stackref) \
|
|
do { \
|
|
_PyStackRef _tmp = (stackref); \
|
|
if (!PyStackRef_IsNull(_tmp)) { \
|
|
PyStackRef_CLOSE(_tmp); \
|
|
} \
|
|
} while (0);
|
|
|
|
|
|
#ifdef Py_GIL_DISABLED
|
|
static inline _PyStackRef
|
|
PyStackRef_DUP(_PyStackRef stackref)
|
|
{
|
|
if (PyStackRef_IsDeferred(stackref)) {
|
|
assert(PyStackRef_IsNull(stackref) ||
|
|
_Py_IsImmortal(PyStackRef_AsPyObjectBorrow(stackref)) ||
|
|
_PyObject_HasDeferredRefcount(PyStackRef_AsPyObjectBorrow(stackref)));
|
|
return stackref;
|
|
}
|
|
Py_INCREF(PyStackRef_AsPyObjectBorrow(stackref));
|
|
return stackref;
|
|
}
|
|
#else
|
|
# define PyStackRef_DUP(stackref) PyStackRef_FromPyObjectSteal(Py_NewRef(PyStackRef_AsPyObjectBorrow(stackref)))
|
|
#endif
|
|
|
|
static inline void
|
|
_PyObjectStack_FromStackRefStack(PyObject **dst, const _PyStackRef *src, size_t length)
|
|
{
|
|
for (size_t i = 0; i < length; i++) {
|
|
dst[i] = PyStackRef_AsPyObjectBorrow(src[i]);
|
|
}
|
|
}
|
|
|
|
// StackRef type checks
|
|
|
|
static inline bool
|
|
PyStackRef_GenCheck(_PyStackRef stackref)
|
|
{
|
|
return PyGen_Check(PyStackRef_AsPyObjectBorrow(stackref));
|
|
}
|
|
|
|
static inline bool
|
|
PyStackRef_BoolCheck(_PyStackRef stackref)
|
|
{
|
|
return PyBool_Check(PyStackRef_AsPyObjectBorrow(stackref));
|
|
}
|
|
|
|
static inline bool
|
|
PyStackRef_LongCheck(_PyStackRef stackref)
|
|
{
|
|
return PyLong_Check(PyStackRef_AsPyObjectBorrow(stackref));
|
|
}
|
|
|
|
static inline bool
|
|
PyStackRef_ExceptionInstanceCheck(_PyStackRef stackref)
|
|
{
|
|
return PyExceptionInstance_Check(PyStackRef_AsPyObjectBorrow(stackref));
|
|
}
|
|
|
|
|
|
static inline bool
|
|
PyStackRef_FunctionCheck(_PyStackRef stackref)
|
|
{
|
|
return PyFunction_Check(PyStackRef_AsPyObjectBorrow(stackref));
|
|
}
|
|
|
|
#ifdef __cplusplus
|
|
}
|
|
#endif
|
|
#endif /* !Py_INTERNAL_STACKREF_H */
|