001 /** 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017 package org.apache.camel.impl; 018 019 import java.util.ArrayList; 020 import java.util.Collection; 021 import java.util.concurrent.ArrayBlockingQueue; 022 import java.util.concurrent.BlockingQueue; 023 import java.util.concurrent.ConcurrentHashMap; 024 025 import org.apache.camel.spi.ServicePool; 026 import org.apache.camel.util.ServiceHelper; 027 import org.apache.commons.logging.Log; 028 import org.apache.commons.logging.LogFactory; 029 030 /** 031 * Default implementation to inherit for a basic service pool. 032 * 033 * @version $Revision: 779038 $ 034 */ 035 public abstract class DefaultServicePool<Key, Service> extends ServiceSupport implements ServicePool<Key, Service> { 036 protected final Log log = LogFactory.getLog(getClass()); 037 protected final ConcurrentHashMap<Key, BlockingQueue<Service>> pool = new ConcurrentHashMap<Key, BlockingQueue<Service>>(); 038 protected final int capacity; 039 040 /** 041 * The capacity, note this is per key. 042 * 043 * @param capacity the capacity per key. 044 */ 045 public DefaultServicePool(int capacity) { 046 this.capacity = capacity; 047 } 048 049 public synchronized Service addAndAcquire(Key key, Service service) { 050 BlockingQueue<Service> entry = pool.get(key); 051 if (entry == null) { 052 entry = new ArrayBlockingQueue<Service>(capacity); 053 pool.put(key, entry); 054 } 055 if (log.isTraceEnabled()) { 056 log.trace("AddAndAcquire key: " + key + " service: " + service); 057 } 058 059 // test if queue will be full 060 if (entry.size() >= capacity) { 061 throw new IllegalStateException("Queue full"); 062 } 063 return service; 064 } 065 066 public synchronized Service acquire(Key key) { 067 BlockingQueue<Service> services = pool.get(key); 068 if (services == null || services.isEmpty()) { 069 if (log.isTraceEnabled()) { 070 log.trace("No free services in pool to acquire for key: " + key); 071 } 072 return null; 073 } 074 075 Service answer = services.poll(); 076 if (log.isTraceEnabled()) { 077 log.trace("Acquire: " + key + " service: " + answer); 078 } 079 return answer; 080 } 081 082 public synchronized void release(Key key, Service service) { 083 if (log.isTraceEnabled()) { 084 log.trace("Release: " + key + " service: " + service); 085 } 086 BlockingQueue<Service> services = pool.get(key); 087 if (services != null) { 088 services.add(service); 089 } 090 } 091 092 protected void doStart() throws Exception { 093 log.debug("Starting service pool: " + this); 094 } 095 096 protected void doStop() throws Exception { 097 log.debug("Stopping service pool: " + this); 098 for (BlockingQueue<Service> entry : pool.values()) { 099 Collection<Service> values = new ArrayList<Service>(); 100 entry.drainTo(values); 101 ServiceHelper.stopServices(values); 102 entry.clear(); 103 } 104 pool.clear(); 105 } 106 107 }