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Fix #2810 - handle the case where some registry calls return 

ERROR_MORE_DATA, requiring another call to get the remaining data.

Patch by Daniel Stutzbach
This commit is contained in:
Brian Curtin 2010-05-26 17:43:50 +00:00
parent 5f22e72e6d
commit 60853211da
3 changed files with 147 additions and 28 deletions
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53
Lib/test/test_winreg.py
View File

@ -5,6 +5,7 @@
import os, sys
import unittest
from test import support
threading = support.import_module("threading")
from platform import machine
# Do this first so test will be skipped if module doesn't exist
@ -227,6 +228,58 @@ class LocalWinregTests(BaseWinregTests):
except WindowsError:
self.assertEqual(h.handle, 0)
def test_changing_value(self):
# Issue2810: A race condition in 2.6 and 3.1 may cause
# EnumValue or QueryValue to throw "WindowsError: More data is
# available"
done = False
class VeryActiveThread(threading.Thread):
def run(self):
with CreateKey(HKEY_CURRENT_USER, test_key_name) as key:
use_short = True
long_string = 'x'*2000
while not done:
s = 'x' if use_short else long_string
use_short = not use_short
SetValue(key, 'changing_value', REG_SZ, s)
thread = VeryActiveThread()
thread.start()
try:
with CreateKey(HKEY_CURRENT_USER,
test_key_name+'\\changing_value') as key:
for _ in range(1000):
num_subkeys, num_values, t = QueryInfoKey(key)
for i in range(num_values):
name = EnumValue(key, i)
QueryValue(key, name[0])
finally:
done = True
thread.join()
DeleteKey(HKEY_CURRENT_USER, test_key_name+'\\changing_value')
DeleteKey(HKEY_CURRENT_USER, test_key_name)
def test_long_key(self):
# Issue2810, in 2.6 and 3.1 when the key name was exactly 256
# characters, EnumKey threw "WindowsError: More data is
# available"
name = 'x'*256
try:
with CreateKey(HKEY_CURRENT_USER, test_key_name) as key:
SetValue(key, name, REG_SZ, 'x')
num_subkeys, num_values, t = QueryInfoKey(key)
EnumKey(key, 0)
finally:
DeleteKey(HKEY_CURRENT_USER, '\\'.join((test_key_name, name)))
DeleteKey(HKEY_CURRENT_USER, test_key_name)
def test_dynamic_key(self):
# Issue2810, when the value is dynamically generated, these
# throw "WindowsError: More data is available" in 2.6 and 3.1
EnumValue(HKEY_PERFORMANCE_DATA, 0)
QueryValueEx(HKEY_PERFORMANCE_DATA, "")
# Reflection requires XP x64/Vista at a minimum. XP doesn't have this stuff
# or DeleteKeyEx so make sure their use raises NotImplementedError
@unittest.skipUnless(WIN_VER < (5, 2), "Requires Windows XP")

3
Misc/NEWS
View File

@ -1220,6 +1220,9 @@ Library
Extension Modules
-----------------
- Issue #2810: Fix cases where the Windows registry API returns
ERROR_MORE_DATA, requiring a re-try in order to get the complete result.
- Issue #8692: Optimize math.factorial: replace the previous naive
algorithm with an improved 'binary-split' algorithm that uses fewer
multiplications and allows many of the multiplications to be

119
PC/winreg.c
View File

@ -1096,7 +1096,14 @@ PyEnumKey(PyObject *self, PyObject *args)
int index;
long rc;
PyObject *retStr;
wchar_t tmpbuf[256]; /* max key name length is 255 */
/* The Windows docs claim that the max key name length is 255
* characters, plus a terminating nul character. However,
* empirical testing demonstrates that it is possible to
* create a 256 character key that is missing the terminating
* nul. RegEnumKeyEx requires a 257 character buffer to
* retrieve such a key name. */
wchar_t tmpbuf[257];
DWORD len = sizeof(tmpbuf); /* includes NULL terminator */
if (!PyArg_ParseTuple(args, "Oi:EnumKey", &obKey, &index))
@ -1123,8 +1130,8 @@ PyEnumValue(PyObject *self, PyObject *args)
long rc;
wchar_t *retValueBuf;
BYTE *retDataBuf;
DWORD retValueSize;
DWORD retDataSize;
DWORD retValueSize, bufValueSize;
DWORD retDataSize, bufDataSize;
DWORD typ;
PyObject *obData;
PyObject *retVal;
@ -1142,6 +1149,8 @@ PyEnumValue(PyObject *self, PyObject *args)
"RegQueryInfoKey");
++retValueSize; /* include null terminators */
++retDataSize;
bufDataSize = retDataSize;
bufValueSize = retValueSize;
retValueBuf = (wchar_t *)PyMem_Malloc(sizeof(wchar_t) * retValueSize);
if (retValueBuf == NULL)
return PyErr_NoMemory();
@ -1151,16 +1160,33 @@ PyEnumValue(PyObject *self, PyObject *args)
return PyErr_NoMemory();
}
Py_BEGIN_ALLOW_THREADS
rc = RegEnumValueW(hKey,
index,
retValueBuf,
&retValueSize,
NULL,
&typ,
retDataBuf,
&retDataSize);
Py_END_ALLOW_THREADS
while (1) {
wchar_t *tmp;
Py_BEGIN_ALLOW_THREADS
rc = RegEnumValueW(hKey,
index,
retValueBuf,
&retValueSize,
NULL,
&typ,
(BYTE *)retDataBuf,
&retDataSize);
Py_END_ALLOW_THREADS
if (rc != ERROR_MORE_DATA)
break;
bufDataSize *= 2;
tmp = (char *)PyMem_Realloc(retDataBuf, bufDataSize);
if (tmp == NULL) {
PyErr_NoMemory();
retVal = NULL;
goto fail;
}
retDataBuf = tmp;
retDataSize = bufDataSize;
retValueSize = bufValueSize;
}
if (rc != ERROR_SUCCESS) {
retVal = PyErr_SetFromWindowsErrWithFunction(rc,
@ -1317,23 +1343,44 @@ PyQueryValue(PyObject *self, PyObject *args)
long rc;
PyObject *retStr;
wchar_t *retBuf;
long bufSize = 0;
DWORD bufSize = 0;
DWORD retSize = 0;
wchar_t *tmp;
if (!PyArg_ParseTuple(args, "OZ:QueryValue", &obKey, &subKey))
return NULL;
if (!PyHKEY_AsHKEY(obKey, &hKey, FALSE))
return NULL;
if ((rc = RegQueryValueW(hKey, subKey, NULL, &bufSize))
!= ERROR_SUCCESS)
rc = RegQueryValueW(hKey, subKey, NULL, &retSize);
if (rc == ERROR_MORE_DATA)
retSize = 256;
else if (rc != ERROR_SUCCESS)
return PyErr_SetFromWindowsErrWithFunction(rc,
"RegQueryValue");
retBuf = (wchar_t *)PyMem_Malloc(bufSize);
bufSize = retSize;
retBuf = (wchar_t *) PyMem_Malloc(bufSize);
if (retBuf == NULL)
return PyErr_NoMemory();
if ((rc = RegQueryValueW(hKey, subKey, retBuf, &bufSize))
!= ERROR_SUCCESS) {
while (1) {
retSize = bufSize;
rc = RegQueryValueW(hKey, subKey, retBuf, &retSize);
if (rc != ERROR_MORE_DATA)
break;
bufSize *= 2;
tmp = (wchar_t *) PyMem_Realloc(retBuf, bufSize);
if (tmp == NULL) {
PyMem_Free(retBuf);
return PyErr_NoMemory();
}
retBuf = tmp;
}
if (rc != ERROR_SUCCESS) {
PyMem_Free(retBuf);
return PyErr_SetFromWindowsErrWithFunction(rc,
"RegQueryValue");
@ -1352,8 +1399,8 @@ PyQueryValueEx(PyObject *self, PyObject *args)
wchar_t *valueName;
long rc;
BYTE *retBuf;
DWORD bufSize = 0;
BYTE *retBuf, *tmp;
DWORD bufSize = 0, retSize;
DWORD typ;
PyObject *obData;
PyObject *result;
@ -1363,18 +1410,34 @@ PyQueryValueEx(PyObject *self, PyObject *args)
if (!PyHKEY_AsHKEY(obKey, &hKey, FALSE))
return NULL;
if ((rc = RegQueryValueExW(hKey, valueName,
NULL, NULL, NULL,
&bufSize))
!= ERROR_SUCCESS)
rc = RegQueryValueExW(hKey, valueName, NULL, NULL, NULL, &bufSize);
if (rc == ERROR_MORE_DATA)
bufSize = 256;
else if (rc != ERROR_SUCCESS)
return PyErr_SetFromWindowsErrWithFunction(rc,
"RegQueryValueEx");
retBuf = (BYTE *)PyMem_Malloc(bufSize);
if (retBuf == NULL)
return PyErr_NoMemory();
if ((rc = RegQueryValueExW(hKey, valueName, NULL,
&typ, retBuf, &bufSize))
!= ERROR_SUCCESS) {
while (1) {
retSize = bufSize;
rc = RegQueryValueExW(hKey, valueName, NULL, &typ,
(BYTE *)retBuf, &retSize);
if (rc != ERROR_MORE_DATA)
break;
bufSize *= 2;
tmp = (char *) PyMem_Realloc(retBuf, bufSize);
if (tmp == NULL) {
PyMem_Free(retBuf);
return PyErr_NoMemory();
}
retBuf = tmp;
}
if (rc != ERROR_SUCCESS) {
PyMem_Free(retBuf);
return PyErr_SetFromWindowsErrWithFunction(rc,
"RegQueryValueEx");