We are observing issues with pthread Mutexes on Apache22/Solaris10. Not sure if this is relevant to this thread, but would appreciate any inputs.
- We are running Apache22 in Worker mode. Apache22 is compiled with gcc346 on Solaris10 - We are having a custom module (DSO) loaded with Apache. On stress test, we see that a mutex is not working as intended. (pthread_mutex_lock) To be precise, we are seeing core dumps and further investigation revealed that there are two threads that have acquired a lock using pthread_mutex_lock, a the same time. Please note that we do not see this behavior on Apache2. This occurs only with Apache22. Has anyone come across a similar situation. Any help in narrowing down the cause would be greatly appreciated! Regards, Venkat. Rainer Jung-3 wrote: > > On 30.03.2009 20:58, Jeff Trawick wrote: >> On Mon, Mar 30, 2009 at 2:33 PM, Jeff Trawick <[email protected] >> <mailto:[email protected]>> wrote: >> >> >> >> On Mon, Mar 30, 2009 at 2:07 PM, Jim Jagielski <[email protected] >> <mailto:[email protected]>> wrote: >> >> Anyone know if: >> >> # POSIX semaphores and cross-process pthread mutexes are not # used >> by default since they have less desirable behaviour when # e.g. a >> process holding the mutex segfaults. >> >> is still applicable, at least for posix sems? >> >> >> AFAIK, the Solaris-specific recovery logic for cross-process pthread >> mutexes has been working reliably for a long time, but with the >> current wind direction APR is choosing fcntl(), which has sysdef >> implementations on that >> >> >> ugh; "sysdef implications" > > and quite often shows EDEADLOCK, even when you can prove there can't be > one. Especially when starting to use more than one lock of that type > (e.g. when SSL comes into the game). > >> platform. >> >> no clues here about the POSIX semaphores > > I would be much interested in an answer as well. Because of the > EDEADLOCK problems I did suggest using the pthread based mutex on > Solaris for a while to people and got no problem reports. But what > experience do others have? > > In a related thread on the Tomcat users list about mod_jk I wrote in > February: > > I now did some searching and it turns out that the implementation of > pthread mutexes for Solaris 10 has very recently changed quite a bit. > So all speculations about improved pthread mutex behaviour > (especially for "robust" mutexes) in the last years might have become > obsolete. > > The new implementation is contained in Solaris kernel patch 137137-09 > and most likely also in Solaris 10 Update 6 (10/08). I didn't check, > whether that update simply contains the kernel patch or the fix is > included independently. > > Some detail is logged in Sunsolve under the bug IDs > > 6296770 2160259 6664275 6697344 6729759 6564706 > > Regards, > > Rainer > > -- View this message in context: http://www.nabble.com/Posix-sems-still-not-recommended--tp22789262p23208772.html Sent from the APR Dev (Apache Portable Runtime) mailing list archive at Nabble.com.
