--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/windows/classes/sun/nio/ch/PendingIoCache.java	Sun Feb 15 12:25:54 2009 +0000
@@ -0,0 +1,161 @@
+/*
+ * 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.*;
+import java.util.*;
+import sun.misc.Unsafe;
+
+/**
+ * Maintains a mapping of pending I/O requests (identified by the address of
+ * an OVERLAPPED structure) to Futures.
+ */
+
+class PendingIoCache {
+    private static final Unsafe unsafe = Unsafe.getUnsafe();
+    private static final int addressSize = unsafe.addressSize();
+
+    private static int dependsArch(int value32, int value64) {
+        return (addressSize == 4) ? value32 : value64;
+    }
+
+    /*
+     * typedef struct _OVERLAPPED {
+     *     DWORD  Internal;
+     *     DWORD  InternalHigh;
+     *     DWORD  Offset;
+     *     DWORD  OffsetHigh;
+     *     HANDLE hEvent;
+     * } OVERLAPPED;
+     */
+    private static final int SIZEOF_OVERLAPPED = dependsArch(20, 32);
+
+    // set to true when closed
+    private boolean closed;
+
+    // set to true when thread is waiting for all I/O operations to complete
+    private boolean closePending;
+
+    // maps OVERLAPPED to PendingFuture
+    private final Map<Long,PendingFuture> pendingIoMap =
+        new HashMap<Long,PendingFuture>();
+
+    // per-channel cache of OVERLAPPED structures
+    private long[] overlappedCache = new long[4];
+    private int overlappedCacheCount = 0;
+
+    PendingIoCache() {
+    }
+
+    long add(PendingFuture<?,?> result) {
+        synchronized (this) {
+            if (closed)
+                throw new AssertionError("Should not get here");
+            long ov;
+            if (overlappedCacheCount > 0) {
+                ov = overlappedCache[--overlappedCacheCount];
+            } else {
+                ov = unsafe.allocateMemory(SIZEOF_OVERLAPPED);
+            }
+            pendingIoMap.put(ov, result);
+            return ov;
+        }
+    }
+
+    @SuppressWarnings("unchecked")
+    <V,A> PendingFuture<V,A> remove(long overlapped) {
+        synchronized (this) {
+            PendingFuture<V,A> res = pendingIoMap.remove(overlapped);
+            if (res != null) {
+                if (overlappedCacheCount < overlappedCache.length) {
+                    overlappedCache[overlappedCacheCount++] = overlapped;
+                } else {
+                    // cache full or channel closing
+                    unsafe.freeMemory(overlapped);
+                }
+                // notify closing thread.
+                if (closePending) {
+                    this.notifyAll();
+                }
+            }
+            return res;
+        }
+    }
+
+    void close() {
+        synchronized (this) {
+            if (closed)
+                return;
+
+            // handle the case that where there are I/O operations that have
+            // not completed.
+            if (!pendingIoMap.isEmpty())
+                clearPendingIoMap();
+
+            // release memory for any cached OVERLAPPED structures
+            while (overlappedCacheCount > 0) {
+                unsafe.freeMemory( overlappedCache[--overlappedCacheCount] );
+            }
+
+            // done
+            closed = true;
+        }
+    }
+
+    private void clearPendingIoMap() {
+        assert Thread.holdsLock(this);
+
+        // wait up to 50ms for the I/O operations to complete
+        closePending = true;
+        try {
+            this.wait(50);
+        } catch (InterruptedException x) { }
+        closePending = false;
+        if (pendingIoMap.isEmpty())
+            return;
+
+        // cause all pending I/O operations to fail
+        // simulate the failure of all pending I/O operations.
+        for (Long ov: pendingIoMap.keySet()) {
+            PendingFuture<?,?> result = pendingIoMap.get(ov);
+            assert !result.isDone();
+
+            // make I/O port aware of the stale OVERLAPPED structure
+            Iocp iocp = (Iocp)((Groupable)result.channel()).group();
+            iocp.makeStale(ov);
+
+            // execute a task that invokes the result handler's failed method
+            final Iocp.ResultHandler rh = (Iocp.ResultHandler)result.getContext();
+            Runnable task = new Runnable() {
+                public void run() {
+                    rh.failed(-1, new AsynchronousCloseException());
+                }
+            };
+            iocp.executeOnPooledThread(task);
+        }
+        pendingIoMap.clear();
+    }
+}