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Revert revisions 63943 and 63942 (Issue #1798: Add ctypes calling

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convention that allows safe access to errno)

This code does not yet work on OS X (__thread storage specifier not
available), so i needs a configure check plus a more portable
solution.
This commit is contained in:
Thomas Heller 2008-06-04 20:22:05 +00:00
parent 8f22b88e28
commit d5bb9215c9
7 changed files with 27 additions and 312 deletions
Download patch file Download diff file Expand all files Collapse all files

15
Modules/_ctypes/_ctypes.c
View file

@ -3271,7 +3271,7 @@ CFuncPtr_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
thunk = AllocFunctionCallback(callable,
dict->argtypes,
dict->restype,
dict->flags);
dict->flags & FUNCFLAG_CDECL);
if (!thunk)
return NULL;
@ -5273,17 +5273,6 @@ init_ctypes(void)
if (!m)
return;
#ifdef MS_WIN32
dwTlsIndex_LastError = TlsAlloc();
dwTlsIndex_errno = TlsAlloc();
if (dwTlsIndex_LastError == TLS_OUT_OF_INDEXES
|| dwTlsIndex_errno == TLS_OUT_OF_INDEXES) {
PyErr_SetString(PyExc_MemoryError,
"Could not allocate TLSIndex for LastError value");
return;
}
#endif
_pointer_type_cache = PyDict_New();
if (_pointer_type_cache == NULL)
return;
@ -5405,8 +5394,6 @@ init_ctypes(void)
PyModule_AddObject(m, "FUNCFLAG_STDCALL", PyInt_FromLong(FUNCFLAG_STDCALL));
#endif
PyModule_AddObject(m, "FUNCFLAG_CDECL", PyInt_FromLong(FUNCFLAG_CDECL));
PyModule_AddObject(m, "FUNCFLAG_USE_ERRNO", PyInt_FromLong(FUNCFLAG_USE_ERRNO));
PyModule_AddObject(m, "FUNCFLAG_USE_LASTERROR", PyInt_FromLong(FUNCFLAG_USE_LASTERROR));
PyModule_AddObject(m, "FUNCFLAG_PYTHONAPI", PyInt_FromLong(FUNCFLAG_PYTHONAPI));
PyModule_AddStringConstant(m, "__version__", "1.1.0");

21
Modules/_ctypes/callbacks.c
View file

@ -189,7 +189,6 @@ static void _CallPythonObject(void *mem,
SETFUNC setfunc,
PyObject *callable,
PyObject *converters,
int flags,
void **pArgs)
{
Py_ssize_t i;
@ -272,22 +271,8 @@ static void _CallPythonObject(void *mem,
#define CHECK(what, x) \
if (x == NULL) _AddTraceback(what, "_ctypes/callbacks.c", __LINE__ - 1), PyErr_Print()
if (flags & FUNCFLAG_USE_ERRNO)
_swap_errno();
#ifdef MS_WIN32
if (flags & FUNCFLAG_USE_LASTERROR)
_swap_last_error();
#endif
result = PyObject_CallObject(callable, arglist);
CHECK("'calling callback function'", result);
#ifdef MS_WIN32
if (flags & FUNCFLAG_USE_LASTERROR)
_swap_last_error();
#endif
if (flags & FUNCFLAG_USE_ERRNO)
_swap_errno();
if ((restype != &ffi_type_void) && result) {
PyObject *keep;
assert(setfunc);
@ -337,7 +322,6 @@ static void closure_fcn(ffi_cif *cif,
p->setfunc,
p->callable,
p->converters,
p->flags,
args);
}
@ -367,7 +351,7 @@ static CThunkObject* CThunkObject_new(Py_ssize_t nArgs)
CThunkObject *AllocFunctionCallback(PyObject *callable,
PyObject *converters,
PyObject *restype,
int flags)
int is_cdecl)
{
int result;
CThunkObject *p;
@ -387,7 +371,6 @@ CThunkObject *AllocFunctionCallback(PyObject *callable,
goto error;
}
p->flags = flags;
for (i = 0; i < nArgs; ++i) {
PyObject *cnv = PySequence_GetItem(converters, i);
if (cnv == NULL)
@ -415,7 +398,7 @@ CThunkObject *AllocFunctionCallback(PyObject *callable,
cc = FFI_DEFAULT_ABI;
#if defined(MS_WIN32) && !defined(_WIN32_WCE) && !defined(MS_WIN64)
if ((flags & FUNCFLAG_CDECL) == 0)
if (is_cdecl == 0)
cc = FFI_STDCALL;
#endif
result = ffi_prep_cif(&p->cif, cc,

139
Modules/_ctypes/callproc.c
View file

@ -83,133 +83,6 @@
#define DONT_USE_SEH
#endif
/*
ctypes maintains a module-global, but thread-local, variable that contains
an error number; called 'ctypes_errno' for this discussion. This variable
is a private copy of the systems 'errno' value; the copy is swapped with the
'errno' variable on several occasions.
Foreign functions created with CDLL(..., use_errno=True), when called, swap
the values just before the actual function call, and swapped again
immediately afterwards. The 'use_errno' parameter defaults to False, in
this case 'ctypes_errno' is not touched.
The values are also swapped immeditately before and after ctypes callback
functions are called, if the callbacks are constructed using the new
optional use_errno parameter set to True: CFUNCTYPE(..., use_errno=TRUE) or
WINFUNCTYPE(..., use_errno=True).
Two new ctypes functions are provided to access the 'ctypes_errno' value
from Python:
- ctypes.set_errno(value) sets ctypes_errno to 'value', the previous
ctypes_errno value is returned.
- ctypes.get_errno() returns the current ctypes_errno value.
---
On Windows, the same scheme is implemented for the error value which is
managed by the GetLastError() and SetLastError() windows api calls.
The ctypes functions are 'ctypes.set_last_error(value)' and
'ctypes.get_last_error()', the CDLL and WinDLL optional parameter is named
'use_last_error', defaults to False.
---
On Windows, TlsSetValue and TlsGetValue calls are used to provide thread
local storage for the variables; ctypes compiled with __GNUC__ uses __thread
variables.
*/
#if defined(MS_WIN32)
DWORD dwTlsIndex_LastError;
DWORD dwTlsIndex_errno;
void
_swap_last_error(void)
{
DWORD temp = GetLastError();
SetLastError((DWORD)TlsGetValue(dwTlsIndex_LastError));
TlsSetValue(dwTlsIndex_LastError, (void *)temp);
}
static PyObject *
get_last_error(PyObject *self, PyObject *args)
{
return PyInt_FromLong((DWORD)TlsGetValue(dwTlsIndex_LastError));
}
static PyObject *
set_last_error(PyObject *self, PyObject *args)
{
DWORD new_value, prev_value;
if (!PyArg_ParseTuple(args, "i", &new_value))
return NULL;
prev_value = (DWORD)TlsGetValue(dwTlsIndex_LastError);
TlsSetValue(dwTlsIndex_LastError, (void *)new_value);
return PyInt_FromLong(prev_value);
}
void
_swap_errno(void)
{
int temp = errno;
errno = (int)TlsGetValue(dwTlsIndex_errno);
TlsSetValue(dwTlsIndex_errno, (void *)temp);
}
static PyObject *
get_errno(PyObject *self, PyObject *args)
{
return PyInt_FromLong((int)TlsGetValue(dwTlsIndex_errno));
}
static PyObject *
set_errno(PyObject *self, PyObject *args)
{
int new_value, prev_value;
if (!PyArg_ParseTuple(args, "i", &new_value))
return NULL;
prev_value = (int)TlsGetValue(dwTlsIndex_errno);
TlsSetValue(dwTlsIndex_errno, (void *)new_value);
return PyInt_FromLong(prev_value);
}
#elif defined(__GNUC__)
static __thread int ctypes_errno;
void
_swap_errno(void)
{
int temp = errno;
errno = ctypes_errno;
ctypes_errno = temp;
}
static PyObject *
get_errno(PyObject *self, PyObject *args)
{
return PyInt_FromLong(ctypes_errno);
}
static PyObject *
set_errno(PyObject *self, PyObject *args)
{
int new_errno, prev_errno;
if (!PyArg_ParseTuple(args, "i", &new_errno))
return NULL;
prev_errno = ctypes_errno;
ctypes_errno = new_errno;
return PyInt_FromLong(prev_errno);
}
#else
#error "TLS not implemented in this configuration"
#endif
#ifdef MS_WIN32
PyObject *ComError;
@ -787,11 +660,7 @@ static int _call_function_pointer(int flags,
if ((flags & FUNCFLAG_PYTHONAPI) == 0)
Py_UNBLOCK_THREADS
#endif
if (flags & FUNCFLAG_USE_ERRNO)
_swap_errno();
#ifdef MS_WIN32
if (flags & FUNCFLAG_USE_LASTERROR)
_swap_last_error();
#ifndef DONT_USE_SEH
__try {
#endif
@ -806,11 +675,7 @@ static int _call_function_pointer(int flags,
;
}
#endif
if (flags & FUNCFLAG_USE_LASTERROR)
_swap_last_error();
#endif
if (flags & FUNCFLAG_USE_ERRNO)
_swap_errno();
#ifdef WITH_THREAD
if ((flags & FUNCFLAG_PYTHONAPI) == 0)
Py_BLOCK_THREADS
@ -1802,8 +1667,6 @@ pointer(PyObject *self, PyObject *arg)
}
PyMethodDef module_methods[] = {
{"get_errno", get_errno, METH_NOARGS},
{"set_errno", set_errno, METH_VARARGS},
{"POINTER", POINTER, METH_O },
{"pointer", pointer, METH_O },
{"_unpickle", unpickle, METH_VARARGS },
@ -1812,8 +1675,6 @@ PyMethodDef module_methods[] = {
{"set_conversion_mode", set_conversion_mode, METH_VARARGS, set_conversion_mode_doc},
#endif
#ifdef MS_WIN32
{"get_last_error", get_last_error, METH_NOARGS},
{"set_last_error", set_last_error, METH_VARARGS},
{"CopyComPointer", copy_com_pointer, METH_VARARGS, copy_com_pointer_doc},
{"FormatError", format_error, METH_VARARGS, format_error_doc},
{"LoadLibrary", load_library, METH_VARARGS, load_library_doc},

13
Modules/_ctypes/ctypes.h
View file

@ -87,7 +87,6 @@ typedef struct {
PyObject_VAR_HEAD
ffi_closure *pcl; /* the C callable */
ffi_cif cif;
int flags;
PyObject *converters;
PyObject *callable;
PyObject *restype;
@ -186,7 +185,7 @@ extern PyMethodDef module_methods[];
extern CThunkObject *AllocFunctionCallback(PyObject *callable,
PyObject *converters,
PyObject *restype,
int flags);
int stdcall);
/* a table entry describing a predefined ctypes type */
struct fielddesc {
char code;
@ -304,8 +303,6 @@ PyObject *_CallProc(PPROC pProc,
#define FUNCFLAG_CDECL 0x1
#define FUNCFLAG_HRESULT 0x2
#define FUNCFLAG_PYTHONAPI 0x4
#define FUNCFLAG_USE_ERRNO 0x8
#define FUNCFLAG_USE_LASTERROR 0x10
#define TYPEFLAG_ISPOINTER 0x100
#define TYPEFLAG_HASPOINTER 0x200
@ -424,16 +421,8 @@ extern int IsSimpleSubType(PyObject *obj);
extern PyObject *_pointer_type_cache;
extern void _swap_errno(void);
#ifdef MS_WIN32
extern void _swap_last_error(void);
extern PyObject *ComError;
extern DWORD dwTlsIndex_LastError;
extern DWORD dwTlsIndex_errno;
#endif
/*