appc-dispatcher/appc-dispatcher-common/lock-manager-lib/lock-manager-impl/src/main/java/org/openecomp/appc/lockmanager/impl/sql/pessimistic/MySqlLockManager.java

   1 /*-
   2  * ============LICENSE_START=======================================================
   3  * ONAP : APPC
   4  * ================================================================================
   5  * Copyright (C) 2017 AT&T Intellectual Property. All rights reserved.
   6  * ================================================================================
   7  * Copyright (C) 2017 Amdocs
   8  * =============================================================================
   9  * Licensed under the Apache License, Version 2.0 (the "License");
  10  * you may not use this file except in compliance with the License.
  11  * You may obtain a copy of the License at
  12  *
  13  *      http://www.apache.org/licenses/LICENSE-2.0
  14  *
  15  * Unless required by applicable law or agreed to in writing, software
  16  * distributed under the License is distributed on an "AS IS" BASIS,
  17  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  18  * See the License for the specific language governing permissions and
  19  * limitations under the License.
  20  *
  21  * ECOMP is a trademark and service mark of AT&T Intellectual Property.
  22  * ============LICENSE_END=========================================================
  23  */
  24
  25 package org.openecomp.appc.lockmanager.impl.sql.pessimistic;
  26
  27 import java.sql.CallableStatement;
  28 import java.sql.Connection;
  29 import java.sql.ResultSet;
  30 import java.sql.SQLException;
  31
  32 import org.openecomp.appc.lockmanager.api.LockRuntimeException;
  33
  34 public class MySqlLockManager extends SqlLockManager {
  35
  36         private static final int DEF_CRITICAL_SECTION_WAIT_TIMEOUT = 3;
  37
  38         protected int criticalSectionWaitTimeoutSecs = DEF_CRITICAL_SECTION_WAIT_TIMEOUT;
  39
  40         public void setCriticalSectionWaitTimeoutSecs(int criticalSectionWaitTimeoutSecs) {
  41                 this.criticalSectionWaitTimeoutSecs = criticalSectionWaitTimeoutSecs;
  42         }
  43
  44         @Override
  45         protected void enterCriticalSection(Connection connection, String resource) {
  46                 try {
  47                         CallableStatement statement = connection.prepareCall("SELECT COALESCE(GET_LOCK(?,?),0)");
  48                         try {
  49                                 statement.setString(1, resource);
  50                                 statement.setInt(2, criticalSectionWaitTimeoutSecs);
  51                                 boolean execRes = statement.execute();
  52                                 int result = 0;
  53                                 if(execRes) {
  54                                         ResultSet resultSet = statement.getResultSet();
  55                                         try {
  56                                                 if(resultSet.next()) {
  57                                                         result = resultSet.getInt(1);
  58                                                 }
  59                                         } finally {
  60                                                 resultSet.close();
  61                                         }
  62                                 }
  63                                 if(result != 1) { // lock is not obtained
  64                                         throw new LockRuntimeException("Cannot obtain critical section lock for resource [" + resource + "].");
  65                                 }
  66                         } finally {
  67                                 statement.close();
  68                         }
  69                 } catch(SQLException e) {
  70             throw new LockRuntimeException("Cannot obtain critical section lock for resource [" + resource + "].", e);
  71                 }
  72         }
  73
  74         @Override
  75         protected void leaveCriticalSection(Connection connection, String resource) {
  76                 try {
  77                         CallableStatement statement = connection.prepareCall("SELECT RELEASE_LOCK(?)");
  78                         try {
  79                                 statement.setString(1, resource);
  80                                 statement.execute();
  81                         } finally {
  82                                 statement.close();
  83                         }
  84                 } catch(SQLException e) {
  85                         throw new LockRuntimeException("Error releasing critical section lock.", e);
  86                 }
  87         }
  88 }