cpython/Lib/ctypes
Thomas Heller fbb9c0bf3c Issue #1798: Add ctypes calling convention that allows safe access of errno.
ctypes maintains thread-local storage that has space for two error
numbers: private copies of the system 'errno' value and, on Windows,
the system error code accessed by the GetLastError() and
SetLastError() api functions.

Foreign functions created with CDLL(..., use_errno=True), when called,
swap the system 'errno' value with the private copy 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.

On Windows, foreign functions created with CDLL(...,
use_last_error=True) or WinDLL(..., use_last_error=True) swap the
system LastError value with the ctypes private copy.

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).

New ctypes functions are provided to access the ctypes private copies
from Python:

- ctypes.set_errno(value) and ctypes.set_last_error(value) store
  'value' in the private copy and returns the previous value.

- ctypes.get_errno() and ctypes.get_last_error() returns the current
  ctypes private copies value.
2008-06-06 08:33:46 +00:00
..
macholib Replace 'has_key()' with 'in'. 2008-02-21 18:52:20 +00:00
test Issue #1798: Add ctypes calling convention that allows safe access of errno. 2008-06-06 08:33:46 +00:00
__init__.py Issue #1798: Add ctypes calling convention that allows safe access of errno. 2008-06-06 08:33:46 +00:00
_endian.py Add pep-291 compatibility markers. 2006-06-12 20:56:48 +00:00
util.py Issue 1793: Add ctypes.util.find_msvcrt() function (on Windows). 2008-05-16 20:06:31 +00:00
wintypes.py Correct the name of a field in the WIN32_FIND_DATAA and WIN32_FIND_DATAW structures. 2007-05-30 07:01:25 +00:00