[cx-oracle-users] curs.bindnames ACESS_VIOLATION crash with cx_Oracle 5.0.3 unicode build on Windows Python 2.6.5

[Henning v. B. <H.v...@t-...>]

Hi,

I am converting an existing application to cx_Oracle 5.0.3 Unicode on Windows with Python 2.6.5.

With cx_Oracle 4.4, iso-8859-1 and bytestrings, it worked.

Now, with Unicode, it crashes with ACCESS_VIOLATION at the call to curs.bindnames()
The database is using NLS_CHARACTERSET='UTF8',
NLS_LANG is set to GERMAN_GERMANY.UTF8.

    curs = conn.cursor()
    perflog.info("Vor prepare")
    curs.prepare(
u"""begin
   update BRLRS
   set    STATUS = 'STARTING'
   ,      DAT_STATUS = SYSDATE
   ,      RESOURCES_USED = 0
   ,      RESOURCES_MAX = 0
   where  RECO_ID   = :RECO_ID
   and    HOST_IP = :HOST_IP
   and    HOST_PORT = :SERVER_PORT
   ;
   if SQL%ROWCOUNT = 0 then
       raise NO_DATA_FOUND; -- LRS ist nicht im Repository eingetragen.
   end if;
end;""")
    perflog.info("Nach Prepare")
    try:
        perflog.info("Vor bindnames")
        k = curs.bindnames()
        perflog.info("nach bindnames")
    except:
        perflog.error("Exception beim Zugriff auf bindnames")
        k = []

Note:

1) I do not get any Python exception, but the python process crashes with ACCESS_VIOLATION (exit code -1073741819).
The last line in the log output is "Vor bindnames".

2) The connection is from a Session Pool and it's using an InputTypeHandler as follows:
      conn = dbtools.session_pool.acquire()
      conn.setupConnection("something")

# Code excerpt from dbtools:

log = logging.getLogger("main")

def uc(val):
    "UTF8-Strings nach Unicode konvertieren"
    log.info("uc called for %r", val)
    if isinstance(val, str):
        if log.isEnabledFor(logging.DEBUG):
            log.debug("Conversion necessary from utf-8 to unicode for value %r, called from %s", val, inspect.stack()[1][1:4])
        try:
            return val.decode("utf-8")
        except:
            log.exception("Value is not utf-8!")
            return val.decode("utf-8", errors="replace")
    return val
    
def InputTypeHandler(cursor, value, numElements):
    "UTF8-Strings nach Unicode umwandeln"
    log.info("InputTypeHandler called for %r", value)
    if isinstance(value, str):
        try:
            1/0
        except:
            log.exception("Conversion from utf-8 to unicode for value=%r", value)
        return cursor.var(unicode, arraysize=numElements, inconverter=uc) 
    return None

def createSessionPool(*args, **kwargs):
    """
    Wrapper zum Erzeugen des Session Pools.
    """
    global session_pool
    if cx_Oracle.version >= "4.4" and cx_Oracle.version[0].isdigit():
        session_pool = cx_Oracle.SessionPool(*args, **kwargs)
    else:
        session_pool = DummySessionPool(*args, **kwargs)

def setupConnection (conn, threadDescr):
    """
    Schreibt Informationen in die V$SESSION.
    Setzt außerdem die Session so, dass immer in UTC gerechnet wird.
    """
    conn.inputtypehandler = InputTypeHandler
    rechnerDescr = u"Bla Bla Bla"
    curs = conn.cursor()
    _ = curs.callproc (u"dbms_session.reset_package", tuple())
    _ = curs.callproc (u"dbms_application_info.set_module", (u"BlaBla", uc(threadDescr[:32])))
    _ = curs.callproc (u"dbms_application_info.set_client_info", (uc(rechnerDescr[:64]), ))
    _ = curs.execute (u"alter session set TIME_ZONE='+00:00'")
    curs.close()


Any ideas?

Henning