X-Recipient: archive-cygwin AT delorie DOT com X-Spam-Check-By: sourceware.org Date: Mon, 1 Dec 2008 22:07:04 -0500 From: Christopher Faylor To: cygwin AT cygwin DOT com Subject: Re: pthread_rwlock_rdlock() returns EDEADLK when trying to call it > once Message-ID: <20081202030703.GB2466@ednor.casa.cgf.cx> Reply-To: cygwin AT cygwin DOT com Mail-Followup-To: cygwin AT cygwin DOT com References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: 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: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , 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 Mon, Dec 01, 2008 at 09:41:53PM +0100, kalle ko wrote: >Possible bug in winsup/cygwin/thread.cc: >... >int >pthread_rwlock::rdlock () >{ > int result = 0; > struct RWLOCK_READER *reader; > pthread_t self = pthread::self (); > > mtx.lock (); > > if (lookup_reader (self)) > { > result = EDEADLK; > goto DONE; > } >... > >It doesn't seem like it's possible for a thread to call >pthread_rwlock_rdlock() multiple times, and if a thread does, it will get >a EDEADLK error. > >http://opengroup.org/onlinepubs/007908799/xsh/pthread_rwlock_rdlock.html: > ... > A thread may hold multiple concurrent read locks on rwlock (that is, > successfully call the pthread_rwlock_rdlock() function n times). > ... > [EDEADLK] > The current thread already owns the read-write lock for writing. > ... > >I noticed this when one of my tests failed. You've located the code. Feel free to suggest a patch. cgf -- 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/