org.apache.qpid.proton.reactor.Selector Maven / Gradle / Ivy
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*
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* to you under the Apache License, Version 2.0 (the
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*
* http://www.apache.org/licenses/LICENSE-2.0
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package org.apache.qpid.proton.reactor;
import java.io.IOException;
import java.util.Iterator;
/**
* A multiplexor of instances of {@link Selectable}.
*
* Many instances of Selectable can be added to a selector, and
* the {@link #select(long)} method used to block the calling thread until
* one of the Selectables becomes read to perform an operation.
*
* This class is not thread safe, so only one thread should be manipulating the
* contents of the selector, or running the {@link #select(long)} method at
* any given time.
*/
public interface Selector {
/**
* Adds a selectable to the selector.
* @param selectable
* @throws IOException
*/
void add(Selectable selectable) throws IOException;
/**
* Updates the selector to reflect any changes interest by the specified
* selectable. This is achieved by calling the
* {@link Selectable#isReading()} and {@link Selectable#isWriting()}
* methods.
* @param selectable
*/
void update(Selectable selectable);
/**
* Removes a selectable from the selector.
* @param selectable
*/
void remove(Selectable selectable);
/**
* Waits for the specified timeout period for one or more selectables to
* become ready for an operation. Selectables that become ready are
* returned by the {@link #readable()}, {@link #writeable()},
* {@link #expired()}, or {@link #error()} methods.
*
* @param timeout the maximum number of milliseconds to block the calling
* thread waiting for a selectable to become ready for an
* operation. The value zero is interpreted as check but
* don't block.
* @throws IOException
*/
void select(long timeout) throws IOException;
/**
* @return the selectables that have become readable since the last call
* to {@link #select(long)}. Calling select clears
* any previous values in this set before adding new values
* corresponding to those selectables that have become readable.
*/
Iterator readable();
/**
* @return the selectables that have become writable since the last call
* to {@link #select(long)}. Calling select clears
* any previous values in this set before adding new values
* corresponding to those selectables that have become writable.
*/
Iterator writeable();
/**
* @return the selectables that have expired since the last call
* to {@link #select(long)}. Calling select clears
* any previous values in this set before adding new values
* corresponding to those selectables that have now expired.
*/
Iterator expired();
/**
* @return the selectables that have encountered an error since the last
* call to {@link #select(long)}. Calling select
* clears any previous values in this set before adding new values
* corresponding to those selectables that have encountered an
* error.
*/
Iterator error() ;
/** Frees the resources used by this selector. */
void free();
}