1. 07 Jan, 2002 3 commits
    • Tom Lane's avatar
      Tweak LWLock algorithms so that an awakened waiter for a lock is not · 5b9a0583
      Tom Lane authored
      granted the lock when awakened; the signal now only means that the lock
      is potentially available.  The waiting process must retry its attempt
      to get the lock when it gets to run.  This allows the lock releasing
      process to re-acquire the lock later in its timeslice.  Since LWLocks
      are usually held for short periods, it is possible for a process to
      acquire and release the same lock many times in a timeslice.  The old
      spinlock-based implementation of these locks allowed for that; but the
      original coding of LWLock would force a process swap for each acquisition
      if there was any contention.  Although this approach reopens the door to
      process starvation (a waiter might repeatedly fail to get the lock),
      the odds of that being a big problem seem low, and the performance cost
      of the previous approach is considerable.
      5b9a0583
    • Michael Meskes's avatar
    • Peter Eisentraut's avatar
      Editorial review · 731204e0
      Peter Eisentraut authored
      731204e0
  2. 06 Jan, 2002 5 commits
  3. 05 Jan, 2002 2 commits
  4. 04 Jan, 2002 12 commits
  5. 03 Jan, 2002 18 commits