tree b6afaaf0c59ce4d17d52e236bb73907fcd58070c
parent e3584f9c28833ec0530b39540ffd406ee41dbc3a
author gabor@google.com <gabor@google.com@62dab493-f737-651d-591e-8d6aee1b9529> 1314904082 +0000
committer gabor@google.com <gabor@google.com@62dab493-f737-651d-591e-8d6aee1b9529> 1314904082 +0000

Bugfixes: for Get(), don't hold mutex while writing log.

- Fix bug in Get: when it triggers a compaction, it could sometimes
  mark the compaction with the wrong level (if there was a gap
  in the set of levels examined for the Get).

- Do not hold mutex while writing to the log file or to the
  MANIFEST file.

  Added a new benchmark that runs a writer thread concurrently with
  reader threads.

  Percentiles
  ------------------------------
  micros/op: avg  median 99   99.9  99.99  99.999 max
  ------------------------------------------------------
  before:    42   38     110  225   32000  42000  48000
  after:     24   20     55   65    130    1100   7000

- Fixed race in optimized Get.  It should have been using the
  pinned memtables, not the current memtables.


git-svn-id: https://leveldb.googlecode.com/svn/trunk@50 62dab493-f737-651d-591e-8d6aee1b9529