I am sad to see that my comment regarding wsrep_is_BF_lock_timeout()
that I made in https://github.com/MariaDB/server/commit/b74b53f0515b360bb5cddec1a506a2f4d4dc21b3#r52293813
(June 17) has not been addressed. Do we really need that output? Do we
see that output in our internal testing? If not, then we have not
tested that that code is free from race conditions or hangs. (It
should be a lot safer to avoid such unnecessary unlock/lock exercises
involving multiple mutexes.) If yes, then why have we not added source
code comments to document when such scenarios would occur? I believe
that it is better to rely on some operating system features (such as
stack traces from a debugger) rather than to try to implement partial
logging.