Hi Michal, We will try on Fedora 23, it has glibc-2.22. Note that we did three things: 1. Changed semaphore with condition variable; 2. Introduced locking in HandleResponse() and WaitForResponse() (this also enforces memory synchronization between threads); 3. Added while (pStatus == 0) around cond.Wait() to account for spurious wakeups. My point above was that I suspect 2. to be the major thing here. Let's see ... Yes, I saw the Ugly hacks and all that goes with them :) Matevz -- You are receiving this because you are subscribed to this thread. Reply to this email directly or view it on GitHub: https://github.com/xrootd/xrootd/issues/404#issuecomment-240778658 ######################################################################## Use REPLY-ALL to reply to list To unsubscribe from the XROOTD-DEV list, click the following link: https://listserv.slac.stanford.edu/cgi-bin/wa?SUBED1=XROOTD-DEV&A=1