| /* |
| * Copyright (c) 2008, 2009, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| package sun.nio.ch; |
| |
| import java.nio.channels.spi.AsynchronousChannelProvider; |
| import java.nio.channels.*; |
| import java.io.IOException; |
| import java.io.Closeable; |
| import java.io.FileDescriptor; |
| import java.util.Map; |
| import java.util.HashMap; |
| import java.util.concurrent.locks.ReadWriteLock; |
| import java.util.concurrent.locks.ReentrantReadWriteLock; |
| |
| /** |
| * Base implementation of AsynchronousChannelGroupImpl for Unix systems. |
| */ |
| |
| abstract class Port extends AsynchronousChannelGroupImpl { |
| |
| /** |
| * Implemented by clients registered with this port. |
| */ |
| interface PollableChannel extends Closeable { |
| void onEvent(int events, boolean mayInvokeDirect); |
| } |
| |
| // maps fd to "pollable" channel |
| protected final ReadWriteLock fdToChannelLock = new ReentrantReadWriteLock(); |
| protected final Map<Integer,PollableChannel> fdToChannel = |
| new HashMap<Integer,PollableChannel>(); |
| |
| |
| Port(AsynchronousChannelProvider provider, ThreadPool pool) { |
| super(provider, pool); |
| } |
| |
| /** |
| * Register channel identified by its file descriptor |
| */ |
| final void register(int fd, PollableChannel ch) { |
| fdToChannelLock.writeLock().lock(); |
| try { |
| if (isShutdown()) |
| throw new ShutdownChannelGroupException(); |
| fdToChannel.put(Integer.valueOf(fd), ch); |
| } finally { |
| fdToChannelLock.writeLock().unlock(); |
| } |
| } |
| |
| /** |
| * Callback method for implementations that need special handling when fd is |
| * removed (currently only needed in the AIX-Port - see AixPollPort.java). |
| */ |
| protected void preUnregister(int fd) { |
| // Do nothing by default. |
| } |
| |
| /** |
| * Unregister channel identified by its file descriptor |
| */ |
| final void unregister(int fd) { |
| boolean checkForShutdown = false; |
| |
| preUnregister(fd); |
| |
| fdToChannelLock.writeLock().lock(); |
| try { |
| fdToChannel.remove(Integer.valueOf(fd)); |
| |
| // last key to be removed so check if group is shutdown |
| if (fdToChannel.isEmpty()) |
| checkForShutdown = true; |
| |
| } finally { |
| fdToChannelLock.writeLock().unlock(); |
| } |
| |
| // continue shutdown |
| if (checkForShutdown && isShutdown()) { |
| try { |
| shutdownNow(); |
| } catch (IOException ignore) { } |
| } |
| } |
| /** |
| * Register file descriptor with polling mechanism for given events. |
| * The implementation should translate the events as required. |
| */ |
| abstract void startPoll(int fd, int events); |
| |
| @Override |
| final boolean isEmpty() { |
| fdToChannelLock.writeLock().lock(); |
| try { |
| return fdToChannel.isEmpty(); |
| } finally { |
| fdToChannelLock.writeLock().unlock(); |
| } |
| } |
| |
| @Override |
| final Object attachForeignChannel(final Channel channel, FileDescriptor fd) { |
| int fdVal = IOUtil.fdVal(fd); |
| register(fdVal, new PollableChannel() { |
| public void onEvent(int events, boolean mayInvokeDirect) { } |
| public void close() throws IOException { |
| channel.close(); |
| } |
| }); |
| return Integer.valueOf(fdVal); |
| } |
| |
| @Override |
| final void detachForeignChannel(Object key) { |
| unregister((Integer)key); |
| } |
| |
| @Override |
| final void closeAllChannels() { |
| /** |
| * Close channels in batches of up to 128 channels. This allows close |
| * to remove the channel from the map without interference. |
| */ |
| final int MAX_BATCH_SIZE = 128; |
| PollableChannel channels[] = new PollableChannel[MAX_BATCH_SIZE]; |
| int count; |
| do { |
| // grab a batch of up to 128 channels |
| fdToChannelLock.writeLock().lock(); |
| count = 0; |
| try { |
| for (Integer fd: fdToChannel.keySet()) { |
| channels[count++] = fdToChannel.get(fd); |
| if (count >= MAX_BATCH_SIZE) |
| break; |
| } |
| } finally { |
| fdToChannelLock.writeLock().unlock(); |
| } |
| |
| // close them |
| for (int i=0; i<count; i++) { |
| try { |
| channels[i].close(); |
| } catch (IOException ignore) { } |
| } |
| } while (count > 0); |
| } |
| } |