ratpack.exec.ExecController Maven / Gradle / Ivy
/*
* Copyright 2014 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package ratpack.exec;
import com.google.common.util.concurrent.ListeningExecutorService;
import com.google.common.util.concurrent.ListeningScheduledExecutorService;
import io.netty.channel.EventLoopGroup;
/**
* The exec controller manages the execution of operations.
*
* The instance for an application can be obtained via the launch config's {@link ratpack.launch.LaunchConfig#getExecController()} method.
*/
public interface ExecController extends AutoCloseable {
/**
* Indicates whether the current thread is managed by this execution controller.
*
* This will return {@code true} if the current thread is either part of the event loop thread pool or blocking thread pool of the
* application that is backed by this execution controller.
*
* @return true if the current thread is managed by this execution controller
*/
boolean isManagedThread();
/**
* A singleton that can be used from any managed thread to perform asynchronous or blocking operations.
*
* The control is typically used by services that are not inherently tied to any specific execution to perform execution operations
* such as blocking and forking.
*
* If you are using the Guice integration, an instance of this type can be injected.
*
* @return the execution control
*/
ExecControl getControl();
/**
* The event loop (i.e. computation) executor.
*
* This executor wraps Netty's event loop executor to provide callback features by way of Guava's executor extensions.
*
* It is generally preferable to use {@link ExecControl#fork(ratpack.func.Action)} to submit computation work rather than this method,
* which properly initialises Ratpack's execution infrastructure.
*
* @return the executor that performs computation
*/
ListeningScheduledExecutorService getExecutor();
ListeningExecutorService getBlockingExecutor();
/**
* The event loop group used by Netty for this application.
*
* Generally there is no need to access this unless you are doing something directly with Netty.
*
* @return the event loop group
*/
EventLoopGroup getEventLoopGroup();
/**
* The number of threads that will be used for computation.
*
* This is determined by the {@link ratpack.launch.LaunchConfig#getThreads()} value of the launch config that created this controller.
*
* @return the number of threads that will be used for computation
*/
int getNumThreads();
/**
* Shuts down this controller, terminating the event loop and blocking threads.
*
* This method returns immediately, not waiting for the actual shutdown to occur.
*
* Generally, the only time it is necessary to call this method is when using an exec controller directly during testing.
* Calling {@link ratpack.server.RatpackServer#stop()} will inherently call this method.
*/
@Override
void close();
}