default executor used non-daemon threads (#5194)

olavloite · sduskis · commit 575eca4e5ac9 · 2019-05-17T13:03:52.000-04:00
The default executor for GrpcTransportOptions created non-daemon threads possibly keeping applications alive after the main method has finished. This is the cause of #2315.
diff --git a/google-cloud-clients/google-cloud-core-grpc/src/main/java/com/google/cloud/grpc/GrpcTransportOptions.java b/google-cloud-clients/google-cloud-core-grpc/src/main/java/com/google/cloud/grpc/GrpcTransportOptions.java
@@ -31,6 +31,7 @@
 import com.google.cloud.NoCredentials;
 import com.google.cloud.ServiceOptions;
 import com.google.cloud.TransportOptions;
+import com.google.common.util.concurrent.ThreadFactoryBuilder;
 import io.grpc.internal.SharedResourceHolder;
 import io.grpc.internal.SharedResourceHolder.Resource;
 import java.io.IOException;
@@ -54,7 +55,13 @@ public class GrpcTransportOptions implements TransportOptions {
       new Resource<ScheduledExecutorService>() {
         @Override
         public ScheduledExecutorService create() {
-          ScheduledThreadPoolExecutor service = new ScheduledThreadPoolExecutor(8);
+          ScheduledThreadPoolExecutor service =
+              new ScheduledThreadPoolExecutor(
+                  8,
+                  new ThreadFactoryBuilder()
+                      .setDaemon(true)
+                      .setNameFormat("grpc-transport-%d")
+                      .build());
           service.setKeepAliveTime(5, TimeUnit.SECONDS);
           service.allowCoreThreadTimeOut(true);
           service.setRemoveOnCancelPolicy(true);
