Re: Help with hang on empty query (PG 7.3.2,

Steve Wampler wrote:
>
> On Sun, 2003-11-09 at 10:15, Steve Wampler wrote:
> > On Sat, 2003-11-08 at 16:33, Hiroshi Inoue wrote:
> > > > -----Original Message-----
> > > > From: Steve Wampler
> > > >
> > > > On Fri, 2003-11-07 at 09:05, Steve Wampler wrote:
> > > > > I recently upgraded a system from RedHat 8 to RedHat 9, which
> > > > > meant an upgrade of PG 7.2 to 7.3.2. Several applications
> > > > > that are written in a language that relies upon odbc to access
> > > > > postgresql have stopped working.
> > > >
> > > > I've now verified that the same hang occurs when using the
> > > > odbctest program that comes with libiodbc.
> > > >
> > > > Can anyone suggest a way to track this down further? Thanks!
> > >
> > > Could you try to remove ENTER_CONN_CS in CC_send_query
> > > in connection.c and change all RETURN_AFTER_LEAVE_CS(self, ..)
> > > to "return ..(the 2nd parameter) "?
> >
> > Hi Hiroshi,
> >
> > Thanks for the suggestion. I get the same behavior, but
> > the mylog file has more information in it (the other logs
> > are unchanged):
>
> I've done a bit more digging and the apps are hanging in
> a call to pthread_mutex_lock() inside SC_execute(). (I had
> configured the pgsqlodbc library with pthread support.)
>
> Dropping pthread support has fixed the problem, whatever it
> was...

The pthread_mutex_lock call is blocking the thread itself.
I changed the behavior of the mutex in my patch I sent you
in another posting.

regards,
Hiroshi Inoue
http://www.geocities.jp/inocchichichi/psqlodbc/