| /* |
| * Copyright (c) 2005, 2013, 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.io.IOException; |
| import java.nio.channels.*; |
| import java.nio.channels.spi.*; |
| import java.util.*; |
| import sun.misc.*; |
| |
| /** |
| * An implementation of Selector for Linux 2.6+ kernels that uses |
| * the epoll event notification facility. |
| */ |
| class EPollSelectorImpl |
| extends SelectorImpl |
| { |
| |
| // File descriptors used for interrupt |
| protected int fd0; |
| protected int fd1; |
| |
| // The poll object |
| EPollArrayWrapper pollWrapper; |
| |
| // Maps from file descriptors to keys |
| private Map<Integer,SelectionKeyImpl> fdToKey; |
| |
| // True if this Selector has been closed |
| private volatile boolean closed = false; |
| |
| // Lock for interrupt triggering and clearing |
| private final Object interruptLock = new Object(); |
| private boolean interruptTriggered = false; |
| |
| /** |
| * Package private constructor called by factory method in |
| * the abstract superclass Selector. |
| */ |
| EPollSelectorImpl(SelectorProvider sp) throws IOException { |
| super(sp); |
| long pipeFds = IOUtil.makePipe(false); |
| fd0 = (int) (pipeFds >>> 32); |
| fd1 = (int) pipeFds; |
| pollWrapper = new EPollArrayWrapper(); |
| pollWrapper.initInterrupt(fd0, fd1); |
| fdToKey = new HashMap<>(); |
| } |
| |
| protected int doSelect(long timeout) throws IOException { |
| if (closed) |
| throw new ClosedSelectorException(); |
| processDeregisterQueue(); |
| try { |
| begin(); |
| pollWrapper.poll(timeout); |
| } finally { |
| end(); |
| } |
| processDeregisterQueue(); |
| int numKeysUpdated = updateSelectedKeys(); |
| if (pollWrapper.interrupted()) { |
| // Clear the wakeup pipe |
| pollWrapper.putEventOps(pollWrapper.interruptedIndex(), 0); |
| synchronized (interruptLock) { |
| pollWrapper.clearInterrupted(); |
| IOUtil.drain(fd0); |
| interruptTriggered = false; |
| } |
| } |
| return numKeysUpdated; |
| } |
| |
| /** |
| * Update the keys whose fd's have been selected by the epoll. |
| * Add the ready keys to the ready queue. |
| */ |
| private int updateSelectedKeys() { |
| int entries = pollWrapper.updated; |
| int numKeysUpdated = 0; |
| for (int i=0; i<entries; i++) { |
| int nextFD = pollWrapper.getDescriptor(i); |
| SelectionKeyImpl ski = fdToKey.get(Integer.valueOf(nextFD)); |
| // ski is null in the case of an interrupt |
| if (ski != null) { |
| int rOps = pollWrapper.getEventOps(i); |
| if (selectedKeys.contains(ski)) { |
| if (ski.channel.translateAndSetReadyOps(rOps, ski)) { |
| numKeysUpdated++; |
| } |
| } else { |
| ski.channel.translateAndSetReadyOps(rOps, ski); |
| if ((ski.nioReadyOps() & ski.nioInterestOps()) != 0) { |
| selectedKeys.add(ski); |
| numKeysUpdated++; |
| } |
| } |
| } |
| } |
| return numKeysUpdated; |
| } |
| |
| protected void implClose() throws IOException { |
| if (closed) |
| return; |
| closed = true; |
| |
| // prevent further wakeup |
| synchronized (interruptLock) { |
| interruptTriggered = true; |
| } |
| |
| FileDispatcherImpl.closeIntFD(fd0); |
| FileDispatcherImpl.closeIntFD(fd1); |
| |
| pollWrapper.closeEPollFD(); |
| // it is possible |
| selectedKeys = null; |
| |
| // Deregister channels |
| Iterator<SelectionKey> i = keys.iterator(); |
| while (i.hasNext()) { |
| SelectionKeyImpl ski = (SelectionKeyImpl)i.next(); |
| deregister(ski); |
| SelectableChannel selch = ski.channel(); |
| if (!selch.isOpen() && !selch.isRegistered()) |
| ((SelChImpl)selch).kill(); |
| i.remove(); |
| } |
| |
| fd0 = -1; |
| fd1 = -1; |
| } |
| |
| protected void implRegister(SelectionKeyImpl ski) { |
| if (closed) |
| throw new ClosedSelectorException(); |
| SelChImpl ch = ski.channel; |
| Integer fd = Integer.valueOf(ch.getFDVal()); |
| fdToKey.put(fd, ski); |
| pollWrapper.add(fd); |
| keys.add(ski); |
| } |
| |
| protected void implDereg(SelectionKeyImpl ski) throws IOException { |
| assert (ski.getIndex() >= 0); |
| SelChImpl ch = ski.channel; |
| int fd = ch.getFDVal(); |
| fdToKey.remove(Integer.valueOf(fd)); |
| pollWrapper.remove(fd); |
| ski.setIndex(-1); |
| keys.remove(ski); |
| selectedKeys.remove(ski); |
| deregister((AbstractSelectionKey)ski); |
| SelectableChannel selch = ski.channel(); |
| if (!selch.isOpen() && !selch.isRegistered()) |
| ((SelChImpl)selch).kill(); |
| } |
| |
| public void putEventOps(SelectionKeyImpl ski, int ops) { |
| if (closed) |
| throw new ClosedSelectorException(); |
| SelChImpl ch = ski.channel; |
| pollWrapper.setInterest(ch.getFDVal(), ops); |
| } |
| |
| public Selector wakeup() { |
| synchronized (interruptLock) { |
| if (!interruptTriggered) { |
| pollWrapper.interrupt(); |
| interruptTriggered = true; |
| } |
| } |
| return this; |
| } |
| } |