Repository: kudu Updated Branches: refs/heads/master ddaa766e2 -> a09c89abc
hybrid_clock: restore SleepFor in WaitUntilAfterLocally This seems to have gone missing from commit f2d96437c. The end result is a busy loop, which was probably unintentional. I also removed the loop, which seemed unnecessary with the SleepFor. To test, I wrote a small program that scanned a table at Now() + 10s, after setting --scanner_max_wait_ms to 10000 (default is 1000). Although the wall clock time was the same, the cycle count was far higher per perf stat. Change-Id: Iecbb077b1f88293dcb0ab53e40ff3862f772694e Reviewed-on: http://gerrit.cloudera.org:8080/11495 Tested-by: Kudu Jenkins Reviewed-by: Andrew Wong <aw...@cloudera.com> Project: http://git-wip-us.apache.org/repos/asf/kudu/repo Commit: http://git-wip-us.apache.org/repos/asf/kudu/commit/24b38f73 Tree: http://git-wip-us.apache.org/repos/asf/kudu/tree/24b38f73 Diff: http://git-wip-us.apache.org/repos/asf/kudu/diff/24b38f73 Branch: refs/heads/master Commit: 24b38f73739ef76f69fbe950ff103dc6c1b3e6a8 Parents: ddaa766 Author: Adar Dembo <a...@cloudera.com> Authored: Fri Sep 21 12:27:41 2018 -0700 Committer: David Ribeiro Alves <davidral...@gmail.com> Committed: Mon Sep 24 15:03:30 2018 +0000 ---------------------------------------------------------------------- src/kudu/clock/hybrid_clock.cc | 32 ++++++++++++++++---------------- 1 file changed, 16 insertions(+), 16 deletions(-) ---------------------------------------------------------------------- http://git-wip-us.apache.org/repos/asf/kudu/blob/24b38f73/src/kudu/clock/hybrid_clock.cc ---------------------------------------------------------------------- diff --git a/src/kudu/clock/hybrid_clock.cc b/src/kudu/clock/hybrid_clock.cc index b97fd2d..7e87d4d 100644 --- a/src/kudu/clock/hybrid_clock.cc +++ b/src/kudu/clock/hybrid_clock.cc @@ -291,31 +291,31 @@ Status HybridClock::WaitUntilAfter(const Timestamp& then, SleepFor(MonoDelta::FromMicroseconds(wait_for_usec)); - VLOG(1) << "WaitUntilAfter(): Incoming time(latest): " << then_latest_usec << " Now(earliest): " << now_earliest_usec << " error: " << error << " Waiting for: " << wait_for_usec; - return Status::OK(); } Status HybridClock::WaitUntilAfterLocally(const Timestamp& then, const MonoTime& deadline) { - while (true) { - Timestamp now; - uint64_t error; - { - std::lock_guard<simple_spinlock> lock(lock_); - NowWithError(&now, &error); - } - if (now > then) { - return Status::OK(); - } - uint64_t wait_for_usec = GetPhysicalValueMicros(then) - GetPhysicalValueMicros(now); - - // Check that sleeping wouldn't sleep longer than our deadline. - RETURN_NOT_OK(CheckDeadlineNotWithinMicros(deadline, wait_for_usec)); + Timestamp now; + uint64_t error; + { + std::lock_guard<simple_spinlock> lock(lock_); + NowWithError(&now, &error); } + if (now > then) { + return Status::OK(); + } + uint64_t wait_for_usec = GetPhysicalValueMicros(then) - GetPhysicalValueMicros(now); + + // Check that sleeping wouldn't sleep longer than our deadline. + RETURN_NOT_OK(CheckDeadlineNotWithinMicros(deadline, wait_for_usec)); + + SleepFor(MonoDelta::FromMicroseconds(wait_for_usec)); + + return Status::OK(); } bool HybridClock::IsAfter(Timestamp t) {
