Re: [cx-oracle-users] Segmentation fault in Python 3 - Cursor - chained exceptions

[Anthony T. <ant...@gm...>]

I am hoping this weekend to make a new release. It has been far too long! I
need binaries for Python 3.4 and Oracle 12c at the least. :-)


On Wed, May 14, 2014 at 6:28 AM, Boris Dzuba <bor...@gm...> wrote:

> Thank you for the quick response. Do you already have any plans, when will
> new version be released ?
>
>
> 2014-05-13 23:17 GMT+02:00 Anthony Tuininga <ant...@gm...>:
>
>> Thanks for the simple program to demonstrate the problem. :-) I have just
>> pushed a change to the source that resolves this issue. Apparently in
>> Python 3 the first time the exception is referenced it is not normalized
>> and so the error object I am creating is immediately accessible. The second
>> level of exception results in a normalized exception which means that it
>> can't be accessed in the same way. Fortunately the normalization can be
>> forced so that I can access the error object the same way each time. A
>> subtle and rare bug so I appreciate the pointer!
>>
>> Anthony
>>
>>
>> On Tue, May 13, 2014 at 1:15 AM, Boris Dzuba <bor...@gm...>wrote:
>>
>>> Hi all,
>>>
>>> The following test program gives a segmentation fault:
>>>
>>> C:\>python
>>> Python 3.3.3 (v3.3.3:c3896275c0f6, Nov 18 2013, 21:19:30) [MSC v.1600 64
>>> bit (AMD64)] on win32
>>> Type "help", "copyright", "credits" or "license" for more information.
>>> >>> import cx_Oracle
>>> >>> c=cx_Oracle.connect(<connect string>).cursor()
>>> >>> try:
>>> ...     c.execute("select")
>>> ... except:
>>> ...     try:
>>> ...             c.execute("select")
>>> ...     except:
>>> ...             pass
>>> ...
>>>
>>> C:\>
>>>
>>> Access Violation
>>> Faulting application name: python.exe
>>> Fault offset: 0x000000000000cacd
>>>
>>>
>>> Platform: 64bit, Win7, Oracle Client 11g (11.2.0.1.0), python 3.3.3,
>>> cx_Oracle 5.1.2
>>>
>>>
>>>
>>> At a guess, the problem is because in the function
>>> Cursor_SetErrorOffset() /Cursor.c/:
>>>
>>> static void Cursor_SetErrorOffset(
>>>     udt_Cursor *self)                   // cursor to get the error
>>> offset from
>>> {
>>>     PyObject *type, *value, *traceback;
>>>     udt_Error *error;
>>>
>>>     PyErr_Fetch(&type, &value, &traceback);
>>>     if (type == g_DatabaseErrorException) {
>>>         error = (udt_Error*) value;
>>>         OCIAttrGet(self->handle, OCI_HTYPE_STMT, &error->offset, 0,
>>>                 OCI_ATTR_PARSE_ERROR_OFFSET,
>>> self->environment->errorHandle);
>>>     }
>>>     PyErr_Restore(type, value, traceback);
>>> }
>>>
>>> OCIAttrGet() call attempts to write a value to the address
>>> /&error->offset/,
>>> therefore after the end of an allocated memory block of the borrowed
>>> pointer /PyObject *value/
>>>
>>> typedef struct {
>>>     PyObject_HEAD
>>>     sb4 code;
>>>     ub4 offset;
>>>     PyObject *message;
>>>     const char *context;
>>> } udt_Error;
>>>
>>>
>>> Commenting it out /* OCIAttrGet(self->handle, OCI_HTYPE_STMT,
>>> &error->offset, 0, OCI_ATTR_PARSE_ERROR_OFFSET,
>>> self->environment->errorHandle);*/
>>> fix this crash!
>>>
>>>
>>> Regards,
>>> Boris
>>>
>>>
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>>>
>>
>>
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>> Get unparalleled scalability from the best Selenium testing platform
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>>
>
>
> ------------------------------------------------------------------------------
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> Instantly run your Selenium tests across 300+ browser/OS combos.
> Get unparalleled scalability from the best Selenium testing platform
> available
> Simple to use. Nothing to install. Get started now for free."
> http://p.sf.net/sfu/SauceLabs
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> cx-oracle-users mailing list
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