$OpenBSD: patch-jdk_src_solaris_classes_sun_nio_ch_KQueuePort_java,v 1.1 2011/01/11 15:47:50 kurt Exp $
--- jdk/src/solaris/classes/sun/nio/ch/KQueuePort.java.orig	Tue Oct 26 10:58:24 2010
+++ jdk/src/solaris/classes/sun/nio/ch/KQueuePort.java	Tue Oct 26 10:58:29 2010
@@ -0,0 +1,322 @@
+/*
+ * Copyright 2008-2009 Sun Microsystems, Inc.  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.  Sun designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ */
+
+package sun.nio.ch;
+
+import java.nio.channels.spi.AsynchronousChannelProvider;
+import java.io.IOException;
+import java.util.concurrent.ArrayBlockingQueue;
+import java.util.concurrent.RejectedExecutionException;
+import java.util.concurrent.atomic.AtomicInteger;
+import static sun.nio.ch.KQueue.*;
+
+/**
+ * AsynchronousChannelGroup implementation based on the Bsd kqueue facility.
+ */
+
+final class KQueuePort
+    extends Port
+{
+    // maximum number of events to poll at a time
+    private static final int MAX_EPOLL_EVENTS = 512;
+
+    // errors
+    private static final int ENOENT     = 2;
+
+    // kqueue descriptor
+    private final int kqfd;
+
+    // true if kqueue closed
+    private boolean closed;
+
+    // socket pair used for wakeup
+    private final int sp[];
+
+    // number of wakeups pending
+    private final AtomicInteger wakeupCount = new AtomicInteger();
+
+    // address of the poll array passed to kqueue_wait
+    private final long address;
+
+    // encapsulates an event for a channel
+    static class Event {
+        final PollableChannel channel;
+        final int events;
+
+        Event(PollableChannel channel, int events) {
+            this.channel = channel;
+            this.events = events;
+        }
+
+        PollableChannel channel()   { return channel; }
+        int events()                { return events; }
+    }
+
+    // queue of events for cases that a polling thread dequeues more than one
+    // event
+    private final ArrayBlockingQueue<Event> queue;
+    private final Event NEED_TO_POLL = new Event(null, 0);
+    private final Event EXECUTE_TASK_OR_SHUTDOWN = new Event(null, 0);
+
+    KQueuePort(AsynchronousChannelProvider provider, ThreadPool pool)
+        throws IOException
+    {
+        super(provider, pool);
+
+        // open kqueue
+        this.kqfd = kqueueCreate();
+
+        // create socket pair for wakeup mechanism
+        int[] sv = new int[2];
+        try {
+            socketpair(sv);
+            // register one end with kqueue
+            kqueueCtl(kqfd, EPOLL_CTL_ADD, sv[0], POLLIN);
+        } catch (IOException x) {
+            close0(kqfd);
+            throw x;
+        }
+        this.sp = sv;
+
+        // allocate the poll array
+        this.address = allocatePollArray(MAX_EPOLL_EVENTS);
+
+        // create the queue and offer the special event to ensure that the first
+        // threads polls
+        this.queue = new ArrayBlockingQueue<Event>(MAX_EPOLL_EVENTS);
+        this.queue.offer(NEED_TO_POLL);
+    }
+
+    KQueuePort start() {
+        startThreads(new EventHandlerTask());
+        return this;
+    }
+
+    /**
+     * Release all resources
+     */
+    private void implClose() {
+        synchronized (this) {
+            if (closed)
+                return;
+            closed = true;
+        }
+        freePollArray(address);
+        close0(sp[0]);
+        close0(sp[1]);
+        close0(kqfd);
+    }
+
+    private void wakeup() {
+        if (wakeupCount.incrementAndGet() == 1) {
+            // write byte to socketpair to force wakeup
+            try {
+                interrupt(sp[1]);
+            } catch (IOException x) {
+                throw new AssertionError(x);
+            }
+        }
+    }
+
+    @Override
+    void executeOnHandlerTask(Runnable task) {
+        synchronized (this) {
+            if (closed)
+                throw new RejectedExecutionException();
+            offerTask(task);
+            wakeup();
+        }
+    }
+
+    @Override
+    void shutdownHandlerTasks() {
+        /*
+         * If no tasks are running then just release resources; otherwise
+         * write to the one end of the socketpair to wakeup any polling threads.
+         */
+        int nThreads = threadCount();
+        if (nThreads == 0) {
+            implClose();
+        } else {
+            // send interrupt to each thread
+            while (nThreads-- > 0) {
+                wakeup();
+            }
+        }
+    }
+
+    // invoke by clients to register a file descriptor
+    @Override
+    void startPoll(int fd, int events) {
+        // update events (or add to kqueue on first usage)
+        int err = kqueueCtl(kqfd, EPOLL_CTL_MOD, fd, (events | EPOLLONESHOT));
+        if (err == ENOENT)
+            err = kqueueCtl(kqfd, EPOLL_CTL_ADD, fd, (events | EPOLLONESHOT));
+        if (err != 0)
+            throw new AssertionError();     // should not happen
+    }
+
+    /*
+     * Task to process events from kqueue and dispatch to the channel's
+     * onEvent handler.
+     *
+     * Events are retreived from kqueue in batch and offered to a BlockingQueue
+     * where they are consumed by handler threads. A special "NEED_TO_POLL"
+     * event is used to signal one consumer to re-poll when all events have
+     * been consumed.
+     */
+    private class EventHandlerTask implements Runnable {
+        private Event poll() throws IOException {
+            try {
+                for (;;) {
+                    int n = kqueueWait(kqfd, address, MAX_EPOLL_EVENTS);
+                    /*
+                     * 'n' events have been read. Here we map them to their
+                     * corresponding channel in batch and queue n-1 so that
+                     * they can be handled by other handler threads. The last
+                     * event is handled by this thread (and so is not queued).
+                     */
+                    fdToChannelLock.readLock().lock();
+                    try {
+                        while (n-- > 0) {
+                            long eventAddress = getEvent(address, n);
+                            int fd = getDescriptor(eventAddress);
+
+                            // wakeup
+                            if (fd == sp[0]) {
+                                if (wakeupCount.decrementAndGet() == 0) {
+                                    // no more wakeups so drain pipe
+                                    drain1(sp[0]);
+                                }
+
+                                // queue special event if there are more events
+                                // to handle.
+                                if (n > 0) {
+                                    queue.offer(EXECUTE_TASK_OR_SHUTDOWN);
+                                    continue;
+                                }
+                                return EXECUTE_TASK_OR_SHUTDOWN;
+                            }
+
+                            PollableChannel channel = fdToChannel.get(fd);
+                            if (channel != null) {
+                                int events = getEvents(eventAddress);
+                                Event ev = new Event(channel, events);
+
+                                // n-1 events are queued; This thread handles
+                                // the last one except for the wakeup
+                                if (n > 0) {
+                                    queue.offer(ev);
+                                } else {
+                                    return ev;
+                                }
+                            }
+                        }
+                    } finally {
+                        fdToChannelLock.readLock().unlock();
+                    }
+                }
+            } finally {
+                // to ensure that some thread will poll when all events have
+                // been consumed
+                queue.offer(NEED_TO_POLL);
+            }
+        }
+
+        public void run() {
+            Invoker.GroupAndInvokeCount myGroupAndInvokeCount =
+                Invoker.getGroupAndInvokeCount();
+            boolean replaceMe = false;
+            Event ev;
+            try {
+                for (;;) {
+                    // reset invoke count
+                    if (myGroupAndInvokeCount != null)
+                        myGroupAndInvokeCount.resetInvokeCount();
+
+                    try {
+                        replaceMe = false;
+                        ev = queue.take();
+
+                        // no events and this thread has been "selected" to
+                        // poll for more.
+                        if (ev == NEED_TO_POLL) {
+                            try {
+                                ev = poll();
+                            } catch (IOException x) {
+                                x.printStackTrace();
+                                return;
+                            }
+                        }
+                    } catch (InterruptedException x) {
+                        continue;
+                    }
+
+                    // handle wakeup to execute task or shutdown
+                    if (ev == EXECUTE_TASK_OR_SHUTDOWN) {
+                        Runnable task = pollTask();
+                        if (task == null) {
+                            // shutdown request
+                            return;
+                        }
+                        // run task (may throw error/exception)
+                        replaceMe = true;
+                        task.run();
+                        continue;
+                    }
+
+                    // process event
+                    try {
+                        ev.channel().onEvent(ev.events());
+                    } catch (Error x) {
+                        replaceMe = true; throw x;
+                    } catch (RuntimeException x) {
+                        replaceMe = true; throw x;
+                    }
+                }
+            } finally {
+                // last handler to exit when shutdown releases resources
+                int remaining = threadExit(this, replaceMe);
+                if (remaining == 0 && isShutdown()) {
+                    implClose();
+                }
+            }
+        }
+    }
+
+    // -- Native methods --
+
+    private static native void socketpair(int[] sv) throws IOException;
+
+    private static native void interrupt(int fd) throws IOException;
+
+    private static native void drain1(int fd) throws IOException;
+
+    private static native void close0(int fd);
+
+    static {
+        Util.load();
+    }
+}
