[DO NOT MERGE] Test PR for ChannelExecutor as the default Dispatcher executor

src/core/Akka.Tests/Dispatch/ChannelExecutorConfigurationSpec.cs

@@ -30,9 +30,9 @@ public void ChannelExecutor_default_should_be_overriden_by_config()
         {
             var config = ConfigurationFactory.ParseString(@"
 executor = channel-executor
-channel-executor.priority = high");
+channel-executor.priority = normal");
             var configurator = new ChannelExecutorConfigurator(config, Sys.Dispatchers.Prerequisites);
-            configurator.Priority.Should().Be(TaskSchedulerPriority.High);
+            configurator.Priority.Should().Be(TaskSchedulerPriority.Normal);
         }
 
         [Fact]
@@ -59,7 +59,7 @@ public async Task ChannelExecutor_instantiation_should_not_throw_when_config_doe
             dispatcher.Configurator.Config.GetString("executor").Should().Be("channel-executor");
 
             var configurator = new ChannelExecutorConfigurator(dispatcher.Configurator.Config, Sys.Dispatchers.Prerequisites);
-            configurator.Priority.Should().Be(TaskSchedulerPriority.Normal);
+            configurator.Priority.Should().Be(TaskSchedulerPriority.High);
 
             await sys.Terminate();
         }

src/core/Akka/Configuration/Pigeon.conf

@@ -309,11 +309,12 @@ akka {
       #  - "thread-pool-executor" requires a "thread-pool-executor" section
 	  #  - "current-context-executor" requires a "current-context-executor" section
 	  #  - "task-executor" requires a "task-executor" section
+	  #  - "channel-executor" requires a "channel-executor" section
       #  - A FQCN of a class extending ExecutorServiceConfigurator
       executor = "default-executor"
 
 	  # This will be used if you have set "executor = "default-executor"".
-	  # Uses the default .NET threadpool
+	  # Uses the default .NET channel executor
       default-executor {
       }
 
@@ -340,6 +341,10 @@ akka {
         task-peeking-mode = "FIFO"
       }
 
+      channel-executor {
+        priority = "high"
+      }
+
 	  # For running in current synchronization contexts
 	  current-context-executor{}
 
@@ -369,7 +374,7 @@ akka {
     # default dispatcher)
     internal-dispatcher {
       type = "Dispatcher"
-      executor = "fork-join-executor"
+      executor = "channel-executor"
       throughput = 5
 
       fork-join-executor {

src/core/Akka/Dispatch/AbstractDispatcher.cs

@@ -329,6 +329,8 @@ protected ExecutorServiceConfigurator ConfigureExecutor()
                 case null:
                 case "":
                 case "default-executor":
+                case "channel-executor":
+                    return new ChannelExecutorConfigurator(Config, Prerequisites);
                 case "thread-pool-executor":
                     return new ThreadPoolExecutorServiceFactory(Config, Prerequisites);
                 case "fork-join-executor":
@@ -337,8 +339,6 @@ protected ExecutorServiceConfigurator ConfigureExecutor()
                     return new CurrentSynchronizationContextExecutorServiceFactory(Config, Prerequisites);
                 case "task-executor":
                     return new DefaultTaskSchedulerExecutorConfigurator(Config, Prerequisites);
-                case "channel-executor":
-                    return new ChannelExecutorConfigurator(Config, Prerequisites);
                 default:
                     Type executorConfiguratorType = Type.GetType(executor);
                     if (executorConfiguratorType == null)