On 7 November 2013 18:21, Saurabh T <saur...@hotmail.com> wrote: > ---------------------------------------- >> From: fa...@kde.org >> To: valgrind-users@lists.sourceforge.net >> CC: saur...@hotmail.com >> Subject: Re: [Valgrind-users] Helgrind 3.9.0: false positive with >> pthread_mutex_destroy >> Date: Thu, 7 Nov 2013 17:25:57 +0100 >> >> On Thursday 07 November 2013 16:22:56 Saurabh T wrote: >>> Helgrind seems to be reporting false positive data race when >>> pthread_mutex_destroy is called in a different thread from >>> pthread_mutex_unlock. Unfortunately I cannot make a test case, sorry. But >>> here's the relevant output: >>> <snip> >> >> Can you prove that the destroy cannot happen during the unlock? > > Not without code of course, but I dont believe it can. It can however happen > *before* the unlock. I believe this is allowed by the standard? The code is > something like this: > Thread 1: > locks > deletes > unlocks > Thread 2: > locks > does_stuff > unlocks > > saurabh >
That is most definitely wrong. Thread 1 destroys a locked mutex, and according to http://pubs.opengroup.org/onlinepubs/009695399/functions/pthread_mutex_init.html : > Attempting to destroy a locked mutex results in undefined behavior. BR Magnus Reftel ------------------------------------------------------------------------------ November Webinars for C, C++, Fortran Developers Accelerate application performance with scalable programming models. Explore techniques for threading, error checking, porting, and tuning. Get the most from the latest Intel processors and coprocessors. See abstracts and register http://pubads.g.doubleclick.net/gampad/clk?id=60136231&iu=/4140/ostg.clktrk _______________________________________________ Valgrind-users mailing list Valgrind-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/valgrind-users
