Package io.netty.channel

Interface IoHandler

All Known Implementing Classes:

EpollIoHandler, IoUringIoHandler, KQueueIoHandler, LocalIoHandler, NioIoHandler

public interface IoHandler

Handles IO dispatching for an ThreadAwareExecutor. All operations except wakeup() and isCompatible(Class) MUST be executed on the ThreadAwareExecutor thread (which means ThreadAwareExecutor.isExecutorThread(Thread) must return true) and should never be called from the user-directly.

Once a IoHandle is registered via the register(IoHandle) method it's possible to submit IoOps related to the IoHandle via IoRegistration.submit(IoOps). These submitted IoOps are the "source" of IoEvents that are dispatched to the registered IoHandle via the IoHandle.handle(IoRegistration, IoEvent) method. These events must be consumed (and handled) as otherwise they might be reported again until handled.

Method Summary

Modifier and Type	Method	Description
default void	destroy()	Destroy the IoHandler and free all its resources.
default void	initialize()	Initialize this IoHandler.
boolean	isCompatible(java.lang.Class<? extends IoHandle> handleType)	Returns true if the given type is compatible with this IoHandler and so can be registered, false otherwise.
default void	prepareToDestroy()	Prepare to destroy this IoHandler.
IoRegistration	register(IoHandle handle)	Register a IoHandle for IO.
int	run(IoHandlerContext context)	Run the IO handled by this IoHandler.
void	wakeup()	Wakeup the IoHandler, which means if any operation blocks it should be unblocked and return as soon as possible.

Method Detail

initialize

default void initialize()

Initialize this IoHandler.

run

int run(IoHandlerContext context)

Run the IO handled by this IoHandler. The IoHandlerContext should be used to ensure we not execute too long and so block the processing of other task that are scheduled on the ThreadAwareExecutor. This is done by taking IoHandlerContext.delayNanos(long) or IoHandlerContext.deadlineNanos() into account.

Parameters:

context - the IoHandlerContext.

Returns:

the number of IoHandle for which I/O was handled.

prepareToDestroy

default void prepareToDestroy()

Prepare to destroy this IoHandler. This method will be called before destroy() and may be called multiple times.

destroy

default void destroy()

Destroy the IoHandler and free all its resources. Once destroyed using the IoHandler will cause undefined behaviour.

register

IoRegistration register(IoHandle handle)
                 throws java.lang.Exception

Register a IoHandle for IO.

Parameters:

handle - the IoHandle to register.

Throws:

java.lang.Exception - thrown if an error happens during registration.

wakeup

void wakeup()

Wakeup the IoHandler, which means if any operation blocks it should be unblocked and return as soon as possible.

isCompatible

boolean isCompatible(java.lang.Class<? extends IoHandle> handleType)

Returns true if the given type is compatible with this IoHandler and so can be registered, false otherwise.

Parameters:

handleType - the type of the IoHandle.

Returns:

if compatible of not.