rename watchTaskScheduler to highPriorityTaskExecutor

bookkeeper-server/src/main/java/org/apache/bookkeeper/client/BookKeeper.java

@@ -119,8 +119,8 @@ public class BookKeeper implements org.apache.bookkeeper.client.api.BookKeeper {
  private final BookKeeperClientStats clientStats;
  private final double bookieQuarantineRatio;
 
- // Inner thread for WatchTask. Disable external use.
- private final OrderedScheduler watchTaskScheduler;
+ // Inner high priority thread for WatchTask. Disable external use.
+ private final OrderedScheduler highPriorityTaskExecutor;
 
  // whether the event loop group is one we created, or is owned by whoever
  // instantiated us
@@ -427,7 +427,7 @@ public BookKeeper(ClientConfiguration conf, ZooKeeper zk, EventLoopGroup eventLo
 
  // initialize resources
  this.scheduler = OrderedScheduler.newSchedulerBuilder().numThreads(1).name("BookKeeperClientScheduler").build();
- this.watchTaskScheduler =
+ this.highPriorityTaskExecutor =
  OrderedScheduler.newSchedulerBuilder().numThreads(1).name("BookKeeperWatchTaskScheduler").build();
  this.mainWorkerPool = OrderedExecutor.newBuilder()
  .name("BookKeeperClientWorker")
@@ -454,7 +454,7 @@ public BookKeeper(ClientConfiguration conf, ZooKeeper zk, EventLoopGroup eventLo
  }
  this.metadataDriver.initialize(
  conf,
- watchTaskScheduler,
+ highPriorityTaskExecutor,
  rootStatsLogger,
  Optional.ofNullable(zkc));
  } catch (ConfigurationException ce) {
@@ -556,7 +556,7 @@ public BookKeeper(ClientConfiguration conf, ZooKeeper zk, EventLoopGroup eventLo
  statsLogger = NullStatsLogger.INSTANCE;
  clientStats = BookKeeperClientStats.newInstance(statsLogger);
  scheduler = null;
- watchTaskScheduler = null;
+ highPriorityTaskExecutor = null;
  requestTimer = null;
  metadataDriver = null;
  placementPolicy = null;
@@ -1470,9 +1470,9 @@ public void close() throws BKException, InterruptedException {
  }
 
  // Close the watchTask scheduler
- watchTaskScheduler.shutdown();
- if (!watchTaskScheduler.awaitTermination(10, TimeUnit.SECONDS)) {
- LOG.warn("The watchTaskScheduler did not shutdown cleanly");
+ highPriorityTaskExecutor.shutdown();
+ if (!highPriorityTaskExecutor.awaitTermination(10, TimeUnit.SECONDS)) {
+ LOG.warn("The highPriorityTaskExecutor for WatchTask did not shutdown cleanly");
  }
 
  mainWorkerPool.shutdown();