Module org.neo4j.driver

Package org.neo4j.driver.internal.bolt.basicimpl.async.connection

Class EventLoopGroupFactory

java.lang.Object

org.neo4j.driver.internal.bolt.basicimpl.async.connection.EventLoopGroupFactory

public final class EventLoopGroupFactory
extends Object

Manages creation of Netty EventLoopGroups, which are basically Executors that perform IO operations.

Method Summary

Modifier and Type	Method	Description
static void	assertNotInEventLoopThread()	Assert that current thread is not an event loop used for async IO operations.
static Class<? extends io.netty.channel.Channel>	channelClass()	Get class of Channel for AbstractBootstrap.channel(Class) method.
static boolean	isEventLoopThread(Thread thread)	Check if given thread is an event loop IO thread.
static io.netty.channel.EventLoopGroup	newEventLoopGroup(int threadCount)	Create new EventLoopGroup with specified thread count.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Details

channelClass

public static Class<? extends io.netty.channel.Channel> channelClass()

Get class of Channel for AbstractBootstrap.channel(Class) method.

Returns:

class of the channel, which should be consistent with EventLoopGroups returned by newEventLoopGroup(int).

newEventLoopGroup

public static io.netty.channel.EventLoopGroup newEventLoopGroup(int threadCount)

Create new EventLoopGroup with specified thread count. Returned group should by given to AbstractBootstrap.group(EventLoopGroup).

Parameters:

threadCount - amount of IO threads for the new group.

Returns:

new group consistent with channel class returned by channelClass().

assertNotInEventLoopThread

public static void assertNotInEventLoopThread()
                                       throws IllegalStateException

Assert that current thread is not an event loop used for async IO operations. This check is needed because blocking API methods like SimpleQueryRunner.run(String) are implemented on top of corresponding async API methods like AsyncQueryRunner.runAsync(String) using basically Future.get() calls. Deadlocks might happen when IO thread executes blocking API call and has to wait for itself to read from the network.

Throws:

IllegalStateException - when current thread is an event loop IO thread.

isEventLoopThread

public static boolean isEventLoopThread(Thread thread)

Check if given thread is an event loop IO thread.

Parameters:

thread - the thread to check.

Returns:

true when given thread belongs to the event loop, false otherwise.