src/java.base/share/classes/java/nio/channels/Selector.java

*** 27,37 ****
  
  import java.io.Closeable;
  import java.io.IOException;
  import java.nio.channels.spi.SelectorProvider;
  import java.util.Set;
! 
  
  /**
   * A multiplexor of {@link SelectableChannel} objects.
   *
   * <p> A selector may be created by invoking the {@link #open open} method of
--- 27,37 ----
  
  import java.io.Closeable;
  import java.io.IOException;
  import java.nio.channels.spi.SelectorProvider;
  import java.util.Set;
! import java.util.function.Consumer;
  
  /**
   * A multiplexor of {@link SelectableChannel} objects.
   *
   * <p> A selector may be created by invoking the {@link #open open} method of
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--- 295,338 ----
       *          If this selector is closed
       */
      public abstract int selectNow() throws IOException;
  
      /**
+      * Selects keys whose corresponding channels are ready for I/O
+      * operations and passes them to the provided consumer.
+      *
+      * <p> This method performs a non-blocking <a href="#selop">selection
+      * operation</a>.  If no channels have become selectable since the previous
+      * selection operation then this method immediately returns zero.
+      *
+      * <p>The difference between this method and {@link #selectNow()} is that
+      * this method immediately passes the {@link java.nio.channels.SelectionKey} objects
+      * to its handler, rather than updating the key set.</p>
+      *
+      * <p> Invoking this method clears the effect of any previous invocations
+      * of the {@link #wakeup wakeup} method.  </p>
+      *
+      * @return  The number of keys, possibly zero, whose ready-operation sets
+      *          were updated by the selection operation
+      *
+      * @param   handler A handler function which is invoked with new SelectionKey
+      *                  objects When an selection operation occurs. It is called
+      *                  the same number of times as the return value.
+      *
+      * @throws  java.lang.NullPointerException
+      *          if the handler is null.
+      *
+      * @throws  IOException
+      *          If an I/O error occurs
+      *
+      * @throws  ClosedSelectorException
+      *          If this selector is closed
+      */
+     public abstract int selectNow(Consumer<SelectionKey> handler)
+         throws IOException;
+ 
+     /**
       * Selects a set of keys whose corresponding channels are ready for I/O
       * operations.
       *
       * <p> This method performs a blocking <a href="#selop">selection
       * operation</a>.  It returns only after at least one channel is selected,
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--- 362,412 ----
       */
      public abstract int select(long timeout)
          throws IOException;
  
      /**
+      * Selects keys whose corresponding channels are ready for I/O
+      * operations and passes them to the provided consumer.
+      *
+      * <p> This method performs a blocking <a href="#selop">selection
+      * operation</a>.  It returns only after at least one channel is selected,
+      * this selector's {@link #wakeup wakeup} method is invoked, the current
+      * thread is interrupted, or the given timeout period expires, whichever
+      * comes first.
+      *
+      * <p>The difference between this method and {@link #select(long)} is that
+      * this method immediately passes the {@link java.nio.channels.SelectionKey} objects
+      * to its handler, rather than updating the key set.</p>
+      *
+      * <p> This method does not offer real-time guarantees: It schedules the
+      * timeout as if by invoking the {@link Object#wait(long)} method. </p>
+      *
+      * @param   handler A handler function which is invoked with new SelectionKey
+      *                  objects When an selection operation occurs. It is called
+      *                  the same number of times as the return value.
+      *
+      * @param  timeout  If positive, block for up to <tt>timeout</tt>
+      *                  milliseconds, more or less, while waiting for a
+      *                  channel to become ready; if zero, block indefinitely;
+      *                  must not be negative
+      *
+      * @return  The number of keys, possibly zero,
+      *          whose ready-operation sets were updated
+      *
+      * @throws  IOException
+      *          If an I/O error occurs
+      *
+      * @throws  ClosedSelectorException
+      *          If this selector is closed
+      *
+      * @throws  IllegalArgumentException
+      *          If the value of the timeout argument is negative
+      */
+     public abstract int select(Consumer<SelectionKey> handler, long timeout)
+         throws IOException;
+ 
+     /**
       * Selects a set of keys whose corresponding channels are ready for I/O
       * operations.
       *
       * <p> This method performs a blocking <a href="#selop">selection
       * operation</a>.  It returns only after at least one channel is selected,