--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/java.desktop/share/classes/javax/swing/text/SegmentCache.java	Sun Aug 17 15:54:13 2014 +0100
@@ -0,0 +1,127 @@
+/*
+ * Copyright (c) 2001, 2008, 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 javax.swing.text;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * SegmentCache caches <code>Segment</code>s to avoid continually creating
+ * and destroying of <code>Segment</code>s. A common use of this class would
+ * be:
+ * <pre>
+ *   Segment segment = segmentCache.getSegment();
+ *   // do something with segment
+ *   ...
+ *   segmentCache.releaseSegment(segment);
+ * </pre>
+ *
+ */
+class SegmentCache {
+    /**
+     * A global cache.
+     */
+    private static SegmentCache sharedCache = new SegmentCache();
+
+    /**
+     * A list of the currently unused Segments.
+     */
+    private List<Segment> segments;
+
+
+    /**
+     * Returns the shared SegmentCache.
+     */
+    public static SegmentCache getSharedInstance() {
+        return sharedCache;
+    }
+
+    /**
+     * A convenience method to get a Segment from the shared
+     * <code>SegmentCache</code>.
+     */
+    public static Segment getSharedSegment() {
+        return getSharedInstance().getSegment();
+    }
+
+    /**
+     * A convenience method to release a Segment to the shared
+     * <code>SegmentCache</code>.
+     */
+    public static void releaseSharedSegment(Segment segment) {
+        getSharedInstance().releaseSegment(segment);
+    }
+
+
+
+    /**
+     * Creates and returns a SegmentCache.
+     */
+    public SegmentCache() {
+        segments = new ArrayList<Segment>(11);
+    }
+
+    /**
+     * Returns a <code>Segment</code>. When done, the <code>Segment</code>
+     * should be recycled by invoking <code>releaseSegment</code>.
+     */
+    public Segment getSegment() {
+        synchronized(this) {
+            int size = segments.size();
+
+            if (size > 0) {
+                return segments.remove(size - 1);
+            }
+        }
+        return new CachedSegment();
+    }
+
+    /**
+     * Releases a Segment. You should not use a Segment after you release it,
+     * and you should NEVER release the same Segment more than once, eg:
+     * <pre>
+     *   segmentCache.releaseSegment(segment);
+     *   segmentCache.releaseSegment(segment);
+     * </pre>
+     * Will likely result in very bad things happening!
+     */
+    public void releaseSegment(Segment segment) {
+        if (segment instanceof CachedSegment) {
+            synchronized(this) {
+                segment.array = null;
+                segment.count = 0;
+                segments.add(segment);
+            }
+        }
+    }
+
+
+    /**
+     * CachedSegment is used as a tagging interface to determine if
+     * a Segment can successfully be shared.
+     */
+    private static class CachedSegment extends Segment {
+    }
+}