Class EpollEventLoop

java.lang.Object

java.util.concurrent.AbstractExecutorService

io.netty.util.concurrent.AbstractEventExecutor

io.netty.util.concurrent.AbstractScheduledEventExecutor

io.netty.util.concurrent.SingleThreadEventExecutor

io.netty.channel.SingleThreadEventLoop

io.netty.channel.epoll.EpollEventLoop

All Implemented Interfaces:

EventLoop, EventLoopGroup, EventExecutor, EventExecutorGroup, OrderedEventExecutor, Iterable<EventExecutor>, Executor, ExecutorService, ScheduledExecutorService

public class EpollEventLoop
extends SingleThreadEventLoop

EventLoop which uses epoll under the covers. Only works on Linux!

Nested Class Summary

Nested classes/interfaces inherited from class SingleThreadEventLoop

SingleThreadEventLoop.ChannelsReadOnlyIterator<T>

Nested classes/interfaces inherited from class SingleThreadEventExecutor

SingleThreadEventExecutor.NonWakeupRunnable

Nested classes/interfaces inherited from class AbstractEventExecutor

AbstractEventExecutor.LazyRunnable

Field Summary

Fields inherited from class SingleThreadEventLoop

DEFAULT_MAX_PENDING_TASKS

Method Summary

Modifier and Type	Method	Description
protected boolean	afterScheduledTaskSubmitted(long deadlineNanos)	See AbstractScheduledEventExecutor.beforeScheduledTaskSubmitted(long).
protected boolean	beforeScheduledTaskSubmitted(long deadlineNanos)	Called from arbitrary non-EventExecutor threads prior to scheduled task submission.
protected void	cleanup()	Do nothing, sub-classes may override
void	closeFileDescriptors()	This method is intended for use by process checkpoint/restore integration, such as OpenJDK CRaC.
int	getIoRatio()	Returns the percentage of the desired amount of time spent for I/O in the event loop.
protected Queue<Runnable>	newTaskQueue(int maxPendingTasks)	Create a new Queue which will holds the tasks to execute.
void	openFileDescriptors()	This method is intended for use by a process checkpoint/restore integration, such as OpenJDK CRaC.
int	registeredChannels()	Returns the number of Channels registered with this EventLoop or -1 if operation is not supported.
Iterator<Channel>	registeredChannelsIterator()
protected void	run()	Run the tasks in the SingleThreadEventExecutor.taskQueue
void	setIoRatio(int ioRatio)	Sets the percentage of the desired amount of time spent for I/O in the event loop.
protected void	wakeup(boolean inEventLoop)

Methods inherited from class SingleThreadEventLoop

afterRunningAllTasks, executeAfterEventLoopIteration, hasTasks, next, parent, pendingTasks, register, register, register

Methods inherited from class SingleThreadEventExecutor

addShutdownHook, addTask, awaitTermination, confirmShutdown, deadlineNanos, delayNanos, execute, inEventLoop, interruptThread, invokeAll, invokeAll, invokeAny, invokeAny, isShutdown, isShuttingDown, isTerminated, lazyExecute, newTaskQueue, peekTask, pollTask, pollTaskFrom, reject, reject, removeShutdownHook, removeTask, runAllTasks, runAllTasks, runAllTasksFrom, runScheduledAndExecutorTasks, shutdown, shutdownGracefully, takeTask, terminationFuture, threadProperties, updateLastExecutionTime, wakesUpForTask

Methods inherited from class AbstractScheduledEventExecutor

cancelScheduledTasks, deadlineToDelayNanos, getCurrentTimeNanos, hasScheduledTasks, initialNanoTime, nanoTime, nextScheduledTaskDeadlineNanos, nextScheduledTaskNano, pollScheduledTask, pollScheduledTask, schedule, schedule, scheduleAtFixedRate, scheduleWithFixedDelay, validateScheduled

Methods inherited from class AbstractEventExecutor

inEventLoop, iterator, newFailedFuture, newProgressivePromise, newPromise, newSucceededFuture, newTaskFor, newTaskFor, runTask, safeExecute, shutdownGracefully, shutdownNow, submit, submit, submit

Methods inherited from class Object

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

Methods inherited from interface EventExecutor

inEventLoop, inEventLoop, newFailedFuture, newProgressivePromise, newPromise, newSucceededFuture

Methods inherited from interface EventExecutorGroup

isShuttingDown, iterator, schedule, schedule, scheduleAtFixedRate, scheduleWithFixedDelay, shutdown, shutdownGracefully, shutdownGracefully, shutdownNow, submit, submit, submit, terminationFuture

Methods inherited from interface Executor

execute

Methods inherited from interface ExecutorService

awaitTermination, invokeAll, invokeAll, invokeAny, invokeAny, isShutdown, isTerminated

Methods inherited from interface Iterable

forEach, spliterator

Method Details

openFileDescriptors

@UnstableApi
public void openFileDescriptors()

This method is intended for use by a process checkpoint/restore integration, such as OpenJDK CRaC.

wakeup

protected void wakeup(boolean inEventLoop)

Overrides:

wakeup in class SingleThreadEventExecutor

beforeScheduledTaskSubmitted

protected boolean beforeScheduledTaskSubmitted(long deadlineNanos)

Description copied from class: AbstractScheduledEventExecutor

Called from arbitrary non-EventExecutor threads prior to scheduled task submission. Returns true if the EventExecutor thread should be woken immediately to process the scheduled task (if not already awake).

If false is returned, AbstractScheduledEventExecutor.afterScheduledTaskSubmitted(long) will be called with the same value after the scheduled task is enqueued, providing another opportunity to wake the EventExecutor thread if required.

Overrides:

beforeScheduledTaskSubmitted in class AbstractScheduledEventExecutor

Parameters:

deadlineNanos - deadline of the to-be-scheduled task relative to AbstractScheduledEventExecutor.getCurrentTimeNanos()

Returns:

true if the EventExecutor thread should be woken, false otherwise

afterScheduledTaskSubmitted

protected boolean afterScheduledTaskSubmitted(long deadlineNanos)

Description copied from class: AbstractScheduledEventExecutor

See AbstractScheduledEventExecutor.beforeScheduledTaskSubmitted(long). Called only after that method returns false.

Overrides:

afterScheduledTaskSubmitted in class AbstractScheduledEventExecutor

Parameters:

deadlineNanos - relative to AbstractScheduledEventExecutor.getCurrentTimeNanos()

Returns:

true if the EventExecutor thread should be woken, false otherwise

newTaskQueue

protected Queue<Runnable> newTaskQueue(int maxPendingTasks)

Description copied from class: SingleThreadEventExecutor

Create a new Queue which will holds the tasks to execute. This default implementation will return a LinkedBlockingQueue but if your sub-class of SingleThreadEventExecutor will not do any blocking calls on the this Queue it may make sense to @Override this and return some more performant implementation that does not support blocking operations at all.

Overrides:

newTaskQueue in class SingleThreadEventExecutor

getIoRatio

public int getIoRatio()

Returns the percentage of the desired amount of time spent for I/O in the event loop.

setIoRatio

public void setIoRatio(int ioRatio)

Sets the percentage of the desired amount of time spent for I/O in the event loop. The default value is 50, which means the event loop will try to spend the same amount of time for I/O as for non-I/O tasks.

registeredChannels

public int registeredChannels()

Description copied from class: SingleThreadEventLoop

Returns the number of Channels registered with this EventLoop or -1 if operation is not supported. The returned value is not guaranteed to be exact accurate and should be viewed as a best effort.

Overrides:

registeredChannels in class SingleThreadEventLoop

registeredChannelsIterator

public Iterator<Channel> registeredChannelsIterator()

Overrides:

registeredChannelsIterator in class SingleThreadEventLoop

Returns:

read-only iterator of active Channels registered with this EventLoop. The returned value is not guaranteed to be exact accurate and should be viewed as a best effort. This method is expected to be called from within event loop.

run

protected void run()

Description copied from class: SingleThreadEventExecutor

Run the tasks in the SingleThreadEventExecutor.taskQueue

Specified by:

run in class SingleThreadEventExecutor

cleanup

protected void cleanup()

Description copied from class: SingleThreadEventExecutor

Do nothing, sub-classes may override

Overrides:

cleanup in class SingleThreadEventExecutor

closeFileDescriptors

@UnstableApi
public void closeFileDescriptors()

This method is intended for use by process checkpoint/restore integration, such as OpenJDK CRaC. It's up to the caller to ensure that there is no concurrent use of the FDs while these are closed, e.g. by blocking the executor.