X-Recipient: archive-cygwin AT delorie DOT com
X-Spam-Check-By: sourceware.org
Date: Tue, 6 Nov 2007 16:30:26 +0100
From: Corinna Vinschen <corinna-cygwin AT cygwin DOT com>
To: cygwin AT cygwin DOT com
Subject: Re: why is pthread_key_create failing?
Message-ID: <20071106153026.GA1203@calimero.vinschen.de>
Reply-To: cygwin AT cygwin DOT com
Mail-Followup-To: cygwin AT cygwin DOT com
References: <200711061512 DOT 15518 DOT bruno AT clisp DOT org>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <200711061512.15518.bruno@clisp.org>
User-Agent: Mutt/1.5.16 (2007-06-09)
Mailing-List: contact cygwin-help AT cygwin DOT com; run by ezmlm
Precedence: bulk
List-Id: <cygwin.cygwin.com>
List-Unsubscribe: <mailto:cygwin-unsubscribe-archive-cygwin=delorie DOT com AT cygwin DOT com>
List-Subscribe: <mailto:cygwin-subscribe AT cygwin DOT com>
List-Archive: <http://sourceware.org/ml/cygwin/>
List-Post: <mailto:cygwin AT cygwin DOT com>
List-Help: <mailto:cygwin-help AT cygwin DOT com>, <http://sourceware.org/ml/#faqs>
Sender: cygwin-owner AT cygwin DOT com
Mail-Followup-To: cygwin AT cygwin DOT com
Delivered-To: mailing list cygwin AT cygwin DOT com

On Nov  6 15:12, Bruno Haible wrote:
> Hi,
> 
> In the test program below, pthread_key_create is failing with return value
> EBUSY with no good reason.
> [...]
> The Cygwin version that I'm using is:
> $ grep VERSION /usr/include/cygwin/version.h | head -2
> #define CYGWIN_VERSION_DLL_MAJOR 1005
> #define CYGWIN_VERSION_DLL_MINOR 19

Time to update.

However, regardless of the version you're using, it's a bug in Cygwin.
The pthread_key_create function checks the incoming pthread_key_t pointer
for being a valid object already and,if so, bails out with EBUSY.  This
is arguably wrong, as your example shows, which reuses pthread_key_t
slots already used before.  Besides, EBUSY isn't defined as a valid
error code returned by pthread_key_create.

I'll fix that in CVS.  For the time being, a working workaround would
be:

  for (i = KEYS_COUNT - 1; i >= 0; i--) {
    fprintf (stderr, "trying to get key #%d\n", i); fflush (stderr);
    mykeys[i] = (pthread_key_t) NULL;
    int err = pthread_key_create (&mykeys[i], free);
    if (err != 0) { fprintf (stderr, "pthread_key_create -> %d\n", err); abort (); }
  }

Thanks for the testcase!


Corinna

-- 
Corinna Vinschen                  Please, send mails regarding Cygwin to
Cygwin Project Co-Leader          cygwin AT cygwin DOT com
Red Hat

--
Unsubscribe info:      http://cygwin.com/ml/#unsubscribe-simple
Problem reports:       http://cygwin.com/problems.html
Documentation:         http://cygwin.com/docs.html
FAQ:                   http://cygwin.com/faq/