fix: partitionedDml stub was not closed (#213)

The PartitionedDML stub was not closed when Spanner was closed. In addition, Spanner did not wait for the channels to actually close, causing some test cases to (sometimes) log a warning that the channel had not been closed.

Author: olavloite

google-cloud-spanner/src/main/java/com/google/cloud/spanner/spi/v1/GapicSpannerRpc.java

@@ -191,6 +191,12 @@ private synchronized void shutdown() {
  executor.shutdown();
  }
  }
+
+ private void awaitTermination() throws InterruptedException {
+ for (ScheduledExecutorService executor : executors) {
+ executor.awaitTermination(10L, TimeUnit.SECONDS);
+ }
+ }
  }
 
  private static final PathTemplate PROJECT_NAME_TEMPLATE =
@@ -1230,10 +1236,22 @@ GrpcCallContext newCallContext(@Nullable Map<Option, ?> options, String resource
  public void shutdown() {
  this.rpcIsClosed = true;
  this.spannerStub.close();
+ this.partitionedDmlStub.close();
  this.instanceAdminStub.close();
  this.databaseAdminStub.close();
  this.spannerWatchdog.shutdown();
  this.executorProvider.shutdown();
+
+ try {
+ this.spannerStub.awaitTermination(10L, TimeUnit.SECONDS);
+ this.partitionedDmlStub.awaitTermination(10L, TimeUnit.SECONDS);
+ this.instanceAdminStub.awaitTermination(10L, TimeUnit.SECONDS);
+ this.databaseAdminStub.awaitTermination(10L, TimeUnit.SECONDS);
+ this.spannerWatchdog.awaitTermination(10L, TimeUnit.SECONDS);
+ this.executorProvider.awaitTermination();
+ } catch (InterruptedException e) {
+ throw SpannerExceptionFactory.propagateInterrupt(e);
+ }
  }
 
  @Override