Separate async executor

graphql-java-servlet/src/main/java/graphql/kickstart/servlet/GraphQLConfiguration.java

@@ -17,6 +17,8 @@
 import graphql.schema.GraphQLSchema;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.concurrent.Executor;
+import java.util.concurrent.Executors;
 import java.util.function.Supplier;
 import lombok.Getter;
 
@@ -31,6 +33,7 @@ public class GraphQLConfiguration {
   @Getter private final long asyncTimeout;
   private final ContextSetting contextSetting;
   private final GraphQLResponseCacheManager responseCacheManager;
+  @Getter private final Executor asyncExecutor;
   private HttpRequestHandler requestHandler;
 
   private GraphQLConfiguration(
@@ -43,8 +46,10 @@ private GraphQLConfiguration(
       long asyncTimeout,
       ContextSetting contextSetting,
       Supplier<BatchInputPreProcessor> batchInputPreProcessor,
-      GraphQLResponseCacheManager responseCacheManager) {
+      GraphQLResponseCacheManager responseCacheManager,
+      Executor asyncExecutor) {
     this.invocationInputFactory = invocationInputFactory;
+    this.asyncExecutor = asyncExecutor;
     this.graphQLInvoker = graphQLInvoker != null ? graphQLInvoker : queryInvoker.toGraphQLInvoker();
     this.objectMapper = objectMapper;
     this.listeners = listeners;
@@ -137,6 +142,7 @@ public static class Builder {
     private Supplier<BatchInputPreProcessor> batchInputPreProcessorSupplier =
         NoOpBatchInputPreProcessor::new;
     private GraphQLResponseCacheManager responseCacheManager;
+    private Executor asyncExecutor = Executors.newCachedThreadPool();
 
     private Builder(GraphQLInvocationInputFactory.Builder invocationInputFactoryBuilder) {
       this.invocationInputFactoryBuilder = invocationInputFactoryBuilder;
@@ -192,6 +198,11 @@ public Builder asyncTimeout(long asyncTimeout) {
       return this;
     }
 
+    public Builder with(Executor asyncExecutor) {
+      this.asyncExecutor = asyncExecutor;
+      return this;
+    }
+
     public Builder with(ContextSetting contextSetting) {
       if (contextSetting != null) {
         this.contextSetting = contextSetting;
@@ -231,7 +242,8 @@ public GraphQLConfiguration build() {
           asyncTimeout,
           contextSetting,
           batchInputPreProcessorSupplier,
-          responseCacheManager);
+          responseCacheManager,
+          asyncExecutor);
     }
   }
 }

graphql-java-servlet/src/main/java/graphql/kickstart/servlet/HttpRequestInvokerImpl.java

@@ -72,13 +72,15 @@ private void invokeAndHandleAsync(
           }
         };
     asyncContext.addListener(timeoutListener);
-    asyncContext.start(
-        () -> {
-          FutureExecutionResult futureResult = invoke(invocationInput, request, response);
-          futureHolder.set(futureResult);
-          handle(futureResult, request, response, listenerHandler)
-              .thenAccept(it -> asyncContext.complete());
-        });
+    configuration
+        .getAsyncExecutor()
+        .execute(
+            () -> {
+              FutureExecutionResult futureResult = invoke(invocationInput, request, response);
+              futureHolder.set(futureResult);
+              handle(futureResult, request, response, listenerHandler)
+                  .thenAccept(it -> asyncContext.complete());
+            });
   }
 
   private CompletableFuture<Void> handle(

graphql-java-servlet/src/test/groovy/graphql/kickstart/servlet/TestUtils.groovy

@@ -1,7 +1,6 @@
 package graphql.kickstart.servlet
 
 import com.google.common.io.ByteStreams
-import graphql.Directives
 import graphql.Scalars
 import graphql.execution.reactive.SingleSubscriberPublisher
 import graphql.kickstart.execution.context.ContextSetting
@@ -15,7 +14,9 @@ import graphql.schema.idl.SchemaGenerator
 import graphql.schema.idl.SchemaParser
 import graphql.schema.idl.TypeRuntimeWiring
 import graphql.schema.idl.errors.SchemaProblem
+import org.jetbrains.annotations.NotNull
 
+import java.util.concurrent.Executor
 import java.util.concurrent.atomic.AtomicReference
 
 class TestUtils {
@@ -59,6 +60,7 @@ class TestUtils {
         .with(schema)
         .with(contextSetting)
         .with(contextBuilder)
+        .with(executor())
         .build())
     servlet.init(null)
     return servlet
@@ -96,9 +98,19 @@ class TestUtils {
     if (listeners != null) {
       configBuilder.with(Arrays.asList(listeners))
     }
+    configBuilder.with(executor());
     configBuilder.build()
   }
 
+  private static Executor executor() {
+    new Executor() {
+      @Override
+      void execute(@NotNull Runnable command) {
+        command.run()
+      }
+    }
+  }
+
   static def createBatchExecutionHandler() {
     new TestBatchInputPreProcessor()
   }