ACCUMULO-2997 Improve comment about race condition Improves the comment in the threadpool size adjustment code, to clarify what the race condition is, and why it's not really a problem.
Project: http://git-wip-us.apache.org/repos/asf/accumulo/repo Commit: http://git-wip-us.apache.org/repos/asf/accumulo/commit/2016ab93 Tree: http://git-wip-us.apache.org/repos/asf/accumulo/tree/2016ab93 Diff: http://git-wip-us.apache.org/repos/asf/accumulo/diff/2016ab93 Branch: refs/heads/1.6 Commit: 2016ab93cc8960bf9aea0d196cb2297abf6c74ad Parents: 87eec6f Author: Christopher Tubbs <ctubb...@apache.org> Authored: Thu Jan 15 16:07:38 2015 -0500 Committer: Christopher Tubbs <ctubb...@apache.org> Committed: Thu Jan 15 16:07:38 2015 -0500 ---------------------------------------------------------------------- .../java/org/apache/accumulo/server/util/TServerUtils.java | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) ---------------------------------------------------------------------- http://git-wip-us.apache.org/repos/asf/accumulo/blob/2016ab93/server/src/main/java/org/apache/accumulo/server/util/TServerUtils.java ---------------------------------------------------------------------- diff --git a/server/src/main/java/org/apache/accumulo/server/util/TServerUtils.java b/server/src/main/java/org/apache/accumulo/server/util/TServerUtils.java index bece746..ba93227 100644 --- a/server/src/main/java/org/apache/accumulo/server/util/TServerUtils.java +++ b/server/src/main/java/org/apache/accumulo/server/util/TServerUtils.java @@ -221,6 +221,8 @@ public class TServerUtils { SimpleTimer.getInstance().schedule(new Runnable() { @Override public void run() { + // there is a minor race condition between sampling the current state of the thread pool and adjusting it + // however, this isn't really an issue, since it adjusts periodically anyway if (pool.getCorePoolSize() <= pool.getActiveCount()) { int larger = pool.getCorePoolSize() + Math.min(pool.getQueue().size(), 2); log.info("Increasing server thread pool size on " + serverName + " to " + larger); @@ -230,10 +232,6 @@ public class TServerUtils { if (pool.getCorePoolSize() > pool.getActiveCount() + 3) { int smaller = Math.max(numThreads, pool.getCorePoolSize() - 1); if (smaller != pool.getCorePoolSize()) { - // ACCUMULO-2997 there is a race condition here... the active count could be higher by the time - // we decrease the core pool size... so the active count could end up higher than - // the core pool size, in which case everything will be queued... the increase case - // should handle this and prevent deadlock log.info("Decreasing server thread pool size on " + serverName + " to " + smaller); pool.setCorePoolSize(smaller); }
