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 */ 017package org.apache.activemq.transaction; 018 019import java.io.IOException; 020import java.io.InterruptedIOException; 021import java.util.ArrayList; 022import java.util.Collections; 023import java.util.Iterator; 024import java.util.concurrent.Callable; 025import java.util.concurrent.ExecutionException; 026import java.util.concurrent.FutureTask; 027import javax.transaction.xa.XAException; 028import org.apache.activemq.command.TransactionId; 029import org.slf4j.Logger; 030 031/** 032 * Keeps track of all the actions the need to be done when a transaction does a 033 * commit or rollback. 034 * 035 * 036 */ 037public abstract class Transaction { 038 039 public static final byte START_STATE = 0; // can go to: 1,2,3 040 public static final byte IN_USE_STATE = 1; // can go to: 2,3 041 public static final byte PREPARED_STATE = 2; // can go to: 3 042 public static final byte FINISHED_STATE = 3; 043 boolean committed = false; 044 045 private final ArrayList<Synchronization> synchronizations = new ArrayList<Synchronization>(); 046 private byte state = START_STATE; 047 protected FutureTask<?> preCommitTask = new FutureTask<Object>(new Callable<Object>() { 048 public Object call() throws Exception { 049 doPreCommit(); 050 return null; 051 } 052 }); 053 protected FutureTask<?> postCommitTask = new FutureTask<Object>(new Callable<Object>() { 054 public Object call() throws Exception { 055 doPostCommit(); 056 return null; 057 } 058 }); 059 060 public byte getState() { 061 return state; 062 } 063 064 public void setState(byte state) { 065 this.state = state; 066 } 067 068 public boolean isCommitted() { 069 return committed; 070 } 071 072 public void setCommitted(boolean committed) { 073 this.committed = committed; 074 } 075 076 public void addSynchronization(Synchronization r) { 077 synchronized (synchronizations) { 078 synchronizations.add(r); 079 } 080 if (state == START_STATE) { 081 state = IN_USE_STATE; 082 } 083 } 084 085 public Synchronization findMatching(Synchronization r) { 086 int existing = synchronizations.indexOf(r); 087 if (existing != -1) { 088 return synchronizations.get(existing); 089 } 090 return null; 091 } 092 093 public void removeSynchronization(Synchronization r) { 094 synchronizations.remove(r); 095 } 096 097 public void prePrepare() throws Exception { 098 099 // Is it ok to call prepare now given the state of the 100 // transaction? 101 switch (state) { 102 case START_STATE: 103 case IN_USE_STATE: 104 break; 105 default: 106 XAException xae = new XAException("Prepare cannot be called now."); 107 xae.errorCode = XAException.XAER_PROTO; 108 throw xae; 109 } 110 111 // // Run the prePrepareTasks 112 // for (Iterator iter = prePrepareTasks.iterator(); iter.hasNext();) { 113 // Callback r = (Callback) iter.next(); 114 // r.execute(); 115 // } 116 } 117 118 protected void fireBeforeCommit() throws Exception { 119 for (Iterator<Synchronization> iter = synchronizations.iterator(); iter.hasNext();) { 120 Synchronization s = iter.next(); 121 s.beforeCommit(); 122 } 123 } 124 125 protected void fireAfterCommit() throws Exception { 126 for (Iterator<Synchronization> iter = synchronizations.iterator(); iter.hasNext();) { 127 Synchronization s = iter.next(); 128 s.afterCommit(); 129 } 130 } 131 132 public void fireAfterRollback() throws Exception { 133 Collections.reverse(synchronizations); 134 for (Iterator<Synchronization> iter = synchronizations.iterator(); iter.hasNext();) { 135 Synchronization s = iter.next(); 136 s.afterRollback(); 137 } 138 } 139 140 @Override 141 public String toString() { 142 return "Local-" + getTransactionId() + "[synchronizations=" + synchronizations + "]"; 143 } 144 145 public abstract void commit(boolean onePhase) throws XAException, IOException; 146 147 public abstract void rollback() throws XAException, IOException; 148 149 public abstract int prepare() throws XAException, IOException; 150 151 public abstract TransactionId getTransactionId(); 152 153 public abstract Logger getLog(); 154 155 public boolean isPrepared() { 156 return getState() == PREPARED_STATE; 157 } 158 159 public int size() { 160 return synchronizations.size(); 161 } 162 163 protected void waitPostCommitDone(FutureTask<?> postCommitTask) throws XAException, IOException { 164 try { 165 postCommitTask.get(); 166 } catch (InterruptedException e) { 167 throw new InterruptedIOException(e.toString()); 168 } catch (ExecutionException e) { 169 Throwable t = e.getCause(); 170 if (t instanceof XAException) { 171 throw (XAException) t; 172 } else if (t instanceof IOException) { 173 throw (IOException) t; 174 } else { 175 throw new XAException(e.toString()); 176 } 177 } 178 } 179 180 protected void doPreCommit() throws XAException { 181 try { 182 fireBeforeCommit(); 183 } catch (Throwable e) { 184 // I guess this could happen. Post commit task failed 185 // to execute properly. 186 getLog().warn("PRE COMMIT FAILED: ", e); 187 XAException xae = new XAException("PRE COMMIT FAILED"); 188 xae.errorCode = XAException.XAER_RMERR; 189 xae.initCause(e); 190 throw xae; 191 } 192 } 193 194 protected void doPostCommit() throws XAException { 195 try { 196 setCommitted(true); 197 fireAfterCommit(); 198 } catch (Throwable e) { 199 // I guess this could happen. Post commit task failed 200 // to execute properly. 201 getLog().warn("POST COMMIT FAILED: ", e); 202 XAException xae = new XAException("POST COMMIT FAILED"); 203 xae.errorCode = XAException.XAER_RMERR; 204 xae.initCause(e); 205 throw xae; 206 } 207 } 208}