Module java.base
Package java.nio.channels.spi

Class AbstractInterruptibleChannel

java.lang.Object
java.nio.channels.spi.AbstractInterruptibleChannel
All Implemented Interfaces:
Closeable, AutoCloseable, Channel, InterruptibleChannel
Direct Known Subclasses:
FileChannel, SelectableChannel
public abstract class AbstractInterruptibleChannel extends Object implements Channel, InterruptibleChannel
Base implementation class for interruptible channels.

This class encapsulates the low-level machinery required to implement the asynchronous closing and interruption of channels. A concrete channel class must invoke the begin and end methods before and after, respectively, invoking an I/O operation that might block indefinitely. In order to ensure that the end method is always invoked, these methods should be used within a try ... finally block: 

    boolean completed = false;
    try {
        begin();
        completed = ...;    // Perform blocking I/O operation
        return ...;         // Return result
    } finally {
        end(completed);
    }

The completed argument to the end method tells whether or not the I/O operation actually completed, that is, whether it had any effect that would be visible to the invoker. In the case of an operation that reads bytes, for example, this argument should be true if, and only if, some bytes were actually transferred into the invoker's target buffer.

A concrete channel class must also implement the implCloseChannel method in such a way that if it is invoked while another thread is blocked in a native I/O operation upon the channel then that operation will immediately return, either by throwing an exception or by returning normally. If a thread is interrupted or the channel upon which it is blocked is asynchronously closed then the channel's end method will throw the appropriate exception.

This class performs the synchronization required to implement the Channel specification. Implementations of the implCloseChannel method need not synchronize against other threads that might be attempting to close the channel.

Since:
1.4