diff options
author | jfrijters <jfrijters> | 2011-08-22 11:37:14 +0400 |
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committer | jfrijters <jfrijters> | 2011-08-22 11:37:14 +0400 |
commit | 0babaa8c8a9284df2f78d8972c097dc88cc37d17 (patch) | |
tree | dacae13cc600c077455092c85ff3f53c51648718 /openjdk/sun | |
parent | ca2faed1d9185bf1d33f2187f897d9a08cf2a3ca (diff) |
Prepare for forking.
Diffstat (limited to 'openjdk/sun')
-rw-r--r-- | openjdk/sun/nio/ch/Iocp.java | 455 |
1 files changed, 455 insertions, 0 deletions
diff --git a/openjdk/sun/nio/ch/Iocp.java b/openjdk/sun/nio/ch/Iocp.java new file mode 100644 index 00000000..f0b83a1a --- /dev/null +++ b/openjdk/sun/nio/ch/Iocp.java @@ -0,0 +1,455 @@ +/* + * 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.*; +import java.nio.channels.spi.AsynchronousChannelProvider; +import java.io.Closeable; +import java.io.IOException; +import java.io.FileDescriptor; +import java.util.*; +import java.util.concurrent.*; +import java.util.concurrent.locks.ReadWriteLock; +import java.util.concurrent.locks.ReentrantReadWriteLock; +import java.security.AccessController; +import sun.security.action.GetPropertyAction; +import sun.misc.Unsafe; + +/** + * Windows implementation of AsynchronousChannelGroup encapsulating an I/O + * completion port. + */ + +class Iocp extends AsynchronousChannelGroupImpl { + private static final Unsafe unsafe = Unsafe.getUnsafe(); + private static final long INVALID_HANDLE_VALUE = -1L; + private static final boolean supportsThreadAgnosticIo; + + // maps completion key to channel + private final ReadWriteLock keyToChannelLock = new ReentrantReadWriteLock(); + private final Map<Integer,OverlappedChannel> keyToChannel = + new HashMap<Integer,OverlappedChannel>(); + private int nextCompletionKey; + + // handle to completion port + private final long port; + + // true if port has been closed + private boolean closed; + + // the set of "stale" OVERLAPPED structures. These OVERLAPPED structures + // relate to I/O operations where the completion notification was not + // received in a timely manner after the channel is closed. + private final Set<Long> staleIoSet = new HashSet<Long>(); + + Iocp(AsynchronousChannelProvider provider, ThreadPool pool) + throws IOException + { + super(provider, pool); + this.port = + createIoCompletionPort(INVALID_HANDLE_VALUE, 0, 0, fixedThreadCount()); + this.nextCompletionKey = 1; + } + + Iocp start() { + startThreads(new EventHandlerTask()); + return this; + } + + /* + * Channels implements this interface support overlapped I/O and can be + * associated with a completion port. + */ + static interface OverlappedChannel extends Closeable { + /** + * Returns a reference to the pending I/O result. + */ + <V,A> PendingFuture<V,A> getByOverlapped(long overlapped); + } + + /** + * Indicates if this operating system supports thread agnostic I/O. + */ + static boolean supportsThreadAgnosticIo() { + return supportsThreadAgnosticIo; + } + + // release all resources + void implClose() { + synchronized (this) { + if (closed) + return; + closed = true; + } + close0(port); + synchronized (staleIoSet) { + for (Long ov: staleIoSet) { + unsafe.freeMemory(ov); + } + staleIoSet.clear(); + } + } + + @Override + boolean isEmpty() { + keyToChannelLock.writeLock().lock(); + try { + return keyToChannel.isEmpty(); + } finally { + keyToChannelLock.writeLock().unlock(); + } + } + + @Override + final Object attachForeignChannel(final Channel channel, FileDescriptor fdObj) + throws IOException + { + int key = associate(new OverlappedChannel() { + public <V,A> PendingFuture<V,A> getByOverlapped(long overlapped) { + return null; + } + public void close() throws IOException { + channel.close(); + } + }, 0L); + return Integer.valueOf(key); + } + + @Override + final void detachForeignChannel(Object key) { + disassociate((Integer)key); + } + + @Override + void closeAllChannels() { + /** + * On Windows the close operation will close the socket/file handle + * and then wait until all outstanding I/O operations have aborted. + * This is necessary as each channel's cache of OVERLAPPED structures + * can only be freed once all I/O operations have completed. As I/O + * completion requires a lookup of the keyToChannel then we must close + * the channels when not holding the write lock. + */ + final int MAX_BATCH_SIZE = 32; + OverlappedChannel channels[] = new OverlappedChannel[MAX_BATCH_SIZE]; + int count; + do { + // grab a batch of up to 32 channels + keyToChannelLock.writeLock().lock(); + count = 0; + try { + for (Integer key: keyToChannel.keySet()) { + channels[count++] = keyToChannel.get(key); + if (count >= MAX_BATCH_SIZE) + break; + } + } finally { + keyToChannelLock.writeLock().unlock(); + } + + // close them + for (int i=0; i<count; i++) { + try { + channels[i].close(); + } catch (IOException ignore) { } + } + } while (count > 0); + } + + private void wakeup() { + try { + postQueuedCompletionStatus(port, 0); + } catch (IOException e) { + // should not happen + throw new AssertionError(e); + } + } + + @Override + void executeOnHandlerTask(Runnable task) { + synchronized (this) { + if (closed) + throw new RejectedExecutionException(); + offerTask(task); + wakeup(); + } + + } + + @Override + void shutdownHandlerTasks() { + // shutdown all handler threads + int nThreads = threadCount(); + while (nThreads-- > 0) { + wakeup(); + } + } + + /** + * Associate the given handle with this group + */ + int associate(OverlappedChannel ch, long handle) throws IOException { + keyToChannelLock.writeLock().lock(); + + // generate a completion key (if not shutdown) + int key; + try { + if (isShutdown()) + throw new ShutdownChannelGroupException(); + + // generate unique key + do { + key = nextCompletionKey++; + } while ((key == 0) || keyToChannel.containsKey(key)); + + // associate with I/O completion port + if (handle != 0L) { + createIoCompletionPort(handle, port, key, 0); + } + + // setup mapping + keyToChannel.put(key, ch); + } finally { + keyToChannelLock.writeLock().unlock(); + } + return key; + } + + /** + * Disassociate channel from the group. + */ + void disassociate(int key) { + boolean checkForShutdown = false; + + keyToChannelLock.writeLock().lock(); + try { + keyToChannel.remove(key); + + // last key to be removed so check if group is shutdown + if (keyToChannel.isEmpty()) + checkForShutdown = true; + + } finally { + keyToChannelLock.writeLock().unlock(); + } + + // continue shutdown + if (checkForShutdown && isShutdown()) { + try { + shutdownNow(); + } catch (IOException ignore) { } + } + } + + /** + * Invoked when a channel associated with this port is closed before + * notifications for all outstanding I/O operations have been received. + */ + void makeStale(Long overlapped) { + synchronized (staleIoSet) { + staleIoSet.add(overlapped); + } + } + + /** + * Checks if the given OVERLAPPED is stale and if so, releases it. + */ + private void checkIfStale(long ov) { + synchronized (staleIoSet) { + boolean removed = staleIoSet.remove(ov); + if (removed) { + unsafe.freeMemory(ov); + } + } + } + + /** + * The handler for consuming the result of an asynchronous I/O operation. + */ + static interface ResultHandler { + /** + * Invoked if the I/O operation completes successfully. + */ + public void completed(int bytesTransferred, boolean canInvokeDirect); + + /** + * Invoked if the I/O operation fails. + */ + public void failed(int error, IOException ioe); + } + + // Creates IOException for the given I/O error. + private static IOException translateErrorToIOException(int error) { + String msg = getErrorMessage(error); + if (msg == null) + msg = "Unknown error: 0x0" + Integer.toHexString(error); + return new IOException(msg); + } + + /** + * Long-running task servicing system-wide or per-file completion port + */ + private class EventHandlerTask implements Runnable { + public void run() { + Invoker.GroupAndInvokeCount myGroupAndInvokeCount = + Invoker.getGroupAndInvokeCount(); + boolean canInvokeDirect = (myGroupAndInvokeCount != null); + CompletionStatus ioResult = new CompletionStatus(); + boolean replaceMe = false; + + try { + for (;;) { + // reset invoke count + if (myGroupAndInvokeCount != null) + myGroupAndInvokeCount.resetInvokeCount(); + + // wait for I/O completion event + // A error here is fatal (thread will not be replaced) + replaceMe = false; + try { + getQueuedCompletionStatus(port, ioResult); + } catch (IOException x) { + // should not happen + x.printStackTrace(); + return; + } + + // handle wakeup to execute task or shutdown + if (ioResult.completionKey() == 0 && + ioResult.overlapped() == 0L) + { + Runnable task = pollTask(); + if (task == null) { + // shutdown request + return; + } + + // run task + // (if error/exception then replace thread) + replaceMe = true; + task.run(); + continue; + } + + // map key to channel + OverlappedChannel ch = null; + keyToChannelLock.readLock().lock(); + try { + ch = keyToChannel.get(ioResult.completionKey()); + if (ch == null) { + checkIfStale(ioResult.overlapped()); + continue; + } + } finally { + keyToChannelLock.readLock().unlock(); + } + + // lookup I/O request + PendingFuture<?,?> result = ch.getByOverlapped(ioResult.overlapped()); + if (result == null) { + // we get here if the OVERLAPPED structure is associated + // with an I/O operation on a channel that was closed + // but the I/O operation event wasn't read in a timely + // manner. Alternatively, it may be related to a + // tryLock operation as the OVERLAPPED structures for + // these operations are not in the I/O cache. + checkIfStale(ioResult.overlapped()); + continue; + } + + // synchronize on result in case I/O completed immediately + // and was handled by initiator + synchronized (result) { + if (result.isDone()) { + continue; + } + // not handled by initiator + } + + // invoke I/O result handler + int error = ioResult.error(); + ResultHandler rh = (ResultHandler)result.getContext(); + replaceMe = true; // (if error/exception then replace thread) + if (error == 0) { + rh.completed(ioResult.bytesTransferred(), canInvokeDirect); + } else { + rh.failed(error, translateErrorToIOException(error)); + } + } + } finally { + // last thread to exit when shutdown releases resources + int remaining = threadExit(this, replaceMe); + if (remaining == 0 && isShutdown()) { + implClose(); + } + } + } + } + + /** + * Container for data returned by GetQueuedCompletionStatus + */ + private static class CompletionStatus { + private int error; + private int bytesTransferred; + private int completionKey; + private long overlapped; + + private CompletionStatus() { } + int error() { return error; } + int bytesTransferred() { return bytesTransferred; } + int completionKey() { return completionKey; } + long overlapped() { return overlapped; } + } + + // -- native methods -- + + private static native void initIDs(); + + private static native long createIoCompletionPort(long handle, + long existingPort, int completionKey, int concurrency) throws IOException; + + private static native void close0(long handle); + + private static native void getQueuedCompletionStatus(long completionPort, + CompletionStatus status) throws IOException; + + private static native void postQueuedCompletionStatus(long completionPort, + int completionKey) throws IOException; + + private static native String getErrorMessage(int error); + + static { + Util.load(); + initIDs(); + + // thread agnostic I/O on Vista/2008 or newer + String osversion = AccessController.doPrivileged( + new GetPropertyAction("os.version")); + String vers[] = osversion.split("\\."); + supportsThreadAgnosticIo = Integer.parseInt(vers[0]) >= 6; + } +} |