content: /*
   *
   * Licensed to the Apache Software Foundation (ASF) under one
   * or more contributor license agreements.  See the NOTICE file
   * distributed with this work for additional information
   * regarding copyright ownership.  The ASF licenses this file
   * to you 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 org.apache.bookkeeper.util;
  
  import java.net.ServerSocket;
  
  /**
   * Port manager provides free ports to allows multiple instances
   * of the bookkeeper tests to run at once.
   */
  public class PortManager {
  
      /**
       * Return an available port.
       *
       * @return available port.
       */
      public static synchronized int nextFreePort() {
          int exceptionCount = 0;
          while (true) {
              try (ServerSocket ss = new ServerSocket(0)) {
                  return ss.getLocalPort();
              } catch (Exception e) {
                  exceptionCount++;
                  if (exceptionCount > 100) {
                      throw new RuntimeException("Unable to allocate socket port", e);
                  }
              }
          }
      }
  }
  