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