Add Ringbuffer interface an 2 implementations, synchronized (locking) SyncedRingbuffer and lock-free LFRingbuffer.

SyncedRingbuffer is moved from JOGL to GlueGen, and generalized w/ common interface Ringbuffer
to allow testing diff. implementations.

- Added Ringbuffer.AllocEmptyArray factory interface, allowing to pass a constructor
  to construct the generic array.

- Added functionality is growBuffer(..), allowing to either grow a full or empty buffer,
  using Ringbuffer.AllocEmptyArray.

- Removed explicit 'clearRef' at get*(..), always clear the taken reference for better
  interface generalization.

- Added LFRingbuffer, exposing lock-free get*(..) and put*(..) methods
  using the 'Always Keep One Slot Open' pattern using the read/write index as barriers only.

- Ctor's copy an optional passed user array into the internal array,
  utilizing Ringbuffer.AllocEmptyArray.

- Added unit tests.

1 files changed, 214 insertions, 0 deletions

diff --git a/src/java/com/jogamp/common/util/Ringbuffer.java b/src/java/com/jogamp/common/util/Ringbuffer.java
new file mode 100644
index 0000000..733a235
--- /dev/null
+++ b/src/java/com/jogamp/common/util/Ringbuffer.java
@@ -0,0 +1,214 @@
+/**
+ * Copyright 2013 JogAmp Community. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification, are
+ * permitted provided that the following conditions are met:
+ * 
+ *    1. Redistributions of source code must retain the above copyright notice, this list of
+ *       conditions and the following disclaimer.
+ * 
+ *    2. Redistributions in binary form must reproduce the above copyright notice, this list
+ *       of conditions and the following disclaimer in the documentation and/or other materials
+ *       provided with the distribution.
+ * 
+ * THIS SOFTWARE IS PROVIDED BY JogAmp Community ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
+ * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL JogAmp Community OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * 
+ * The views and conclusions contained in the software and documentation are those of the
+ * authors and should not be interpreted as representing official policies, either expressed
+ * or implied, of JogAmp Community.
+ */
+package com.jogamp.common.util;
+
+import java.io.PrintStream;
+
+/** 
+ * Ring buffer interface, a.k.a circular buffer.
+ * <p>
+ * Caller can chose whether to block until get / put is able to proceed or not.
+ * </p>
+ * <p>
+ * Caller can chose whether to pass an empty array and clear references at get,
+ * or using a preset array for circular access of same objects.
+ * </p>
+ * <p>
+ * Synchronization and hence thread safety details belong to the implementation. 
+ * </p>
+ */
+public interface Ringbuffer<T> {
+    
+    /** 
+     * Implementation hook for {@link #growBuffer(Object[], int, AllocEmptyArray)}
+     * to pass an implementation of {@link #newArray(int)}. 
+     * @param <T> type of array
+     */
+    public static interface AllocEmptyArray<T> {
+        /**
+         * Returns a new allocated empty array of generic type T with given size.
+         */
+        public T[] newArray(int size);
+    }
+    
+    /** Returns a short string representation incl. size/capacity and internal r/w index (impl. dependent). */ 
+    public String toString();
+
+    /** Debug functionality - Dumps the contents of the internal array. */
+    public void dump(PrintStream stream, String prefix);
+
+    /** 
+     * Returns the internal array as-is, i.e. w/o a copy.
+     * <p>
+     * The layout and size of the internal array is implementation dependent.
+     * </p> 
+     * <p>
+     * Users shall not modify or rely on the returned array.
+     * </p> 
+     * @deprecated This method should not be required 
+     */
+    public T[] getInternalArray();
+
+    /** Returns the net capacity of this ring buffer. */
+    public int capacity();
+
+    /**
+     * Resets the read and write position according to an empty ring buffer 
+     * and set all ring buffer slots to <code>null</code>.
+     * <p>
+     * {@link #isEmpty()} will return <code>true</code> after calling this method.
+     * </p>
+     */
+    public void clear();
+
+    /**
+     * Resets the read and write position according to a full ring buffer 
+     * and fill all slots w/ elements of array <code>copyFrom</code>.
+     * <p>
+     * Array's <code>copyFrom</code> elements will be copied into the internal array, 
+     * hence it's length must be equal to {@link #capacity()}.
+     * </p>
+     * @param copyFrom Mandatory array w/ length {@link #capacity()} to be copied into the internal array.
+     * @throws IllegalArgumentException if <code>copyFrom</code> is <code>null</code>.   
+     * @throws IllegalArgumentException if <code>copyFrom</code>'s length is different from {@link #capacity()}.
+     */
+    public void resetFull(T[] copyFrom) throws IllegalArgumentException;
+
+    /** Returns the number of elements in this ring buffer. */
+    public int size();
+
+    /** Returns the number of free slots available to put.  */
+    public int getFreeSlots();
+
+    /** Returns true if this ring buffer is empty, otherwise false. */
+    public boolean isEmpty();
+
+    /** Returns true if this ring buffer is full, otherwise false. */
+    public boolean isFull();
+
+    /**
+     * Dequeues the oldest enqueued element if available, otherwise null.
+     * <p>
+     * The returned ring buffer slot will be set to <code>null</code> to release the reference
+     * and move ownership to the caller.
+     * </p>
+     * <p>
+     * Method is non blocking and returns immediately;.
+     * </p>
+     * @return the oldest put element if available, otherwise null.  
+     */
+    public T get();
+
+    /**
+     * Dequeues the oldest enqueued element.
+     * <p>
+     * The returned ring buffer slot will be set to <code>null</code> to release the reference
+     * and move ownership to the caller.
+     * </p>
+     * <p>
+     * Methods blocks until an element becomes available via put.
+     * </p>
+     * @return the oldest put element  
+     * @throws InterruptedException 
+     */
+    public T getBlocking() throws InterruptedException;
+
+    /** 
+     * Peeks the next element at the read position w/o modifying pointer, nor blocking.
+     * @return <code>null</code> if empty, otherwise the element which would be read next.
+     */
+    public T peek();
+
+    /** 
+     * Peeks the next element at the read position w/o modifying pointer, but w/ blocking.
+     * @return <code>null</code> if empty, otherwise the element which would be read next.
+     */
+    public T peekBlocking() throws InterruptedException;
+
+    /** 
+     * Enqueues the given element.
+     * <p>
+     * Returns true if successful, otherwise false in case buffer is full.
+     * </p>
+     * <p>
+     * Method is non blocking and returns immediately;.
+     * </p>
+     */
+    public boolean put(T e);
+
+    /** 
+     * Enqueues the given element.
+     * <p>
+     * Method blocks until a free slot becomes available via get.
+     * </p>
+     * @throws InterruptedException 
+     */
+    public void putBlocking(T e) throws InterruptedException;
+
+    /** 
+     * Enqueues the same element at it's write position, if not full.
+     * <p>
+     * Returns true if successful, otherwise false in case buffer is full.
+     * </p>
+     * <p>
+     * If <code>blocking</code> is true, method blocks until a free slot becomes available via get.
+     * </p>
+     * @param blocking if true, wait until a free slot becomes available via get.
+     * @throws InterruptedException 
+     */
+    public boolean putSame(boolean blocking) throws InterruptedException;
+
+    /**
+     * Blocks until at least <code>count</code> free slots become available.
+     * @throws InterruptedException
+     */
+    public void waitForFreeSlots(int count) throws InterruptedException;
+
+    /**
+     * Grows a full or empty ring buffer, increasing it's capacity about the amount.
+     * <p>
+     * Growing an empty ring buffer increases it's size about the amount, i.e. renders it not empty.
+     * The new elements are inserted at the read position, able to be read out via {@link #get()} etc.
+     * </p>
+     * <p>
+     * Growing a full ring buffer leaves the size intact, i.e. renders it not full.
+     * The new elements are inserted at the write position, able to be written to via {@link #put(Object)} etc.
+     * </p>
+     * 
+     * @param newElements array of new empty elements the buffer shall grow about, maybe <code>null</code>.
+     *        If not <code>null</code>, array size must be <= <code>amount</code>
+     * @param amount the amount of elements the buffer shall grow about
+     * @param allocEmptyArray implementation hook to allocate a new empty array of generic type T
+     * @throws IllegalStateException if buffer is neither full nor empty
+     * @throws IllegalArgumentException if newElements is given but is > amount
+     */
+    public void growBuffer(T[] newElements, int amount,
+            AllocEmptyArray<T> allocEmptyArray) throws IllegalStateException,
+            IllegalArgumentException;
+
+}
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