which is always false. In a very fast InnoDB shutdown, we just ensure that
no more transactions are running, flush InnoDB log, signal InnoDB threads to die,
and then return from InnoDB (from innobase_end()) without waiting for those threads
to actually die. I have tested on a 4CPU machine that even with --innodb_flush_log_at_trx_commit=0,
this optimized InnoDB very fast shutdown loses no committed transactions. Patch pre-approved by Heikki.


innobase/log/log0log.c:
  In an InnoDB very fast shutdown, we just need to wait for no more transactions to be happening
  and then we can flush the InnoDB log and don't need to wait for the
  signaled-to-die InnoDB threads to finish (saves seconds).
innobase/srv/srv0start.c:
  In an InnoDB very fast shutdown, once we have forced a flush of the InnoDB
  log to disk, and signalled InnoDB threads to die, we needn't wait
  for these threads to die.