I also think that you will see a difference between `__sync_bool_compare_and_swap` that you used and `__sync_lock_test_and_set`, because the former also needs to do the comparison. --- Reply to this email directly or view it on GitHub: https://github.com/xrootd/xrootd/pull/266#issuecomment-121961368 ######################################################################## 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