Mercurial > cpython-lru_cache-weakref

diff Modules/_ctypes/callbacks.c @ 47492:ebbf011550cd

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Merged revisions 63977 via svnmerge from svn+ssh://pythondev@svn.python.org/python/trunk ........ r63977 | thomas.heller | 2008-06-06 10:33:46 +0200 (Fri, 06 Jun 2008) | 31 lines 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. ........
author Thomas Heller <theller@ctypes.org>
date Fri, 06 Jun 2008 09:31:40 +0000
parents 23ab586c427a
children 87fbbf22adf3
line wrap: on
line diff
--- a/Modules/_ctypes/callbacks.c	Fri Jun 06 09:13:04 2008 +0000
+++ b/Modules/_ctypes/callbacks.c	Fri Jun 06 09:31:40 2008 +0000
@@ -185,12 +185,15 @@
 			      SETFUNC setfunc,
 			      PyObject *callable,
 			      PyObject *converters,
+			      int flags,
 			      void **pArgs)
 {
 	Py_ssize_t i;
 	PyObject *result;
 	PyObject *arglist = NULL;
 	Py_ssize_t nArgs;
+	PyObject *error_object = NULL;
+	int *space;
 #ifdef WITH_THREAD
 	PyGILState_STATE state = PyGILState_Ensure();
 #endif
@@ -267,8 +270,41 @@
 #define CHECK(what, x) \
 if (x == NULL) _AddTraceback(what, "_ctypes/callbacks.c", __LINE__ - 1), PyErr_Print()
 
+	if (flags & (FUNCFLAG_USE_ERRNO | FUNCFLAG_USE_LASTERROR)) {
+		error_object = get_error_object(&space);
+		if (error_object == NULL)
+			goto Done;
+		if (flags & FUNCFLAG_USE_ERRNO) {
+			int temp = space[0];
+			space[0] = errno;
+			errno = temp;
+		}
+#ifdef MS_WIN32
+		if (flags & FUNCFLAG_USE_LASTERROR) {
+			int temp = space[1];
+			space[1] = GetLastError();
+			SetLastError(temp);
+		}
+#endif
+	}
+
 	result = PyObject_CallObject(callable, arglist);
 	CHECK("'calling callback function'", result);
+
+#ifdef MS_WIN32
+	if (flags & FUNCFLAG_USE_LASTERROR) {
+		int temp = space[1];
+		space[1] = GetLastError();
+		SetLastError(temp);
+	}
+#endif
+	if (flags & FUNCFLAG_USE_ERRNO) {
+		int temp = space[0];
+		space[0] = errno;
+		errno = temp;
+	}
+	Py_XDECREF(error_object);
+
 	if ((restype != &ffi_type_void) && result) {
 		PyObject *keep;
 		assert(setfunc);
@@ -319,6 +355,7 @@
 			  p->setfunc,
 			  p->callable,
 			  p->converters,
+			  p->flags,
 			  args);
 }
 
@@ -348,7 +385,7 @@
 CThunkObject *AllocFunctionCallback(PyObject *callable,
 				    PyObject *converters,
 				    PyObject *restype,
-				    int is_cdecl)
+				    int flags)
 {
 	int result;
 	CThunkObject *p;
@@ -368,6 +405,7 @@
 		goto error;
 	}
 
+	p->flags = flags;
 	for (i = 0; i < nArgs; ++i) {
 		PyObject *cnv = PySequence_GetItem(converters, i);
 		if (cnv == NULL)
@@ -395,7 +433,7 @@
 
 	cc = FFI_DEFAULT_ABI;
 #if defined(MS_WIN32) && !defined(_WIN32_WCE) && !defined(MS_WIN64)
-	if (is_cdecl == 0)
+	if ((flags & FUNCFLAG_CDECL) == 0)
 		cc = FFI_STDCALL;
 #endif
 	result = ffi_prep_cif(&p->cif, cc,