/*
 * Copyright 2015 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package net.kuujo.copycat.io.util;

import java.util.ArrayDeque;
import java.util.Queue;
import java.util.function.Function;

/**
 * Pool of reference counted objects.
 *
 * @author <a href="http://github.com/kuujo">Jordan Halterman</a>
 */
public class ReferencePool<T extends ReferenceCounted<?>> implements ReferenceManager<T>, AutoCloseable {
  private final Function<ReferenceManager<T>, T> factory;
  private final Queue<T> pool = new ArrayDeque<>(1024);

  public ReferencePool(Function<ReferenceManager<T>, T> factory) {
    if (factory == null)
      throw new NullPointerException("factory cannot be null");
    this.factory = factory;
  }

  /**
   * Acquires a reference.
   *
   * @return The acquired reference.
   */
  public T acquire() {
    synchronized (pool) {
      T reference = pool.poll();
      if (reference == null) {
        reference = factory.apply(this);
      }
      reference.acquire();
      return reference;
    }
  }

  @Override
  public void release(T reference) {
    pool.add(reference);
  }

  @Override
  public void close() {
    synchronized (pool) {
      for (T reference : pool) {
        reference.close();
      }
    }
  }

}

@@ -657,24 +657,19 @@
 va.util.
-ArrayDeq
+Que
 ue;%0Aimpo
@@ -673,32 +673,59 @@
 mport java.util.
+concurrent.ConcurrentLinked
 Queue;%0Aimport ja
@@ -1071,25 +1071,32 @@
 new 
-ArrayDeq
+ConcurrentLinkedQue
 ue%3C%3E(
-1024
 );%0A%0A
@@ -1392,36 +1392,8 @@
 ) %7B%0A
-    synchronized (pool) %7B%0A  
     
@@ -1423,18 +1423,16 @@
 ();%0A    
-  
 if (refe
@@ -1444,26 +1444,24 @@
  == null) %7B%0A
-  
       refere
@@ -1491,22 +1491,18 @@
 s);%0A    
- 
- 
 %7D%0A
-  
     refe
@@ -1522,18 +1522,16 @@
 ();%0A    
-  
 return r
@@ -1540,22 +1540,16 @@
 erence;%0A
-    %7D%0A
   %7D%0A%0A  @
@@ -1664,36 +1664,8 @@
 ) %7B%0A
-    synchronized (pool) %7B%0A  
     
@@ -1693,26 +1693,24 @@
 ol) %7B%0A      
- 
- 
 reference.cl
@@ -1720,16 +1720,8 @@
 ();%0A
-      %7D%0A
     

Use ConcurrentLinkedQueue for object pools.