| Classes in this File | Line Coverage | Branch Coverage | Complexity | ||||
| ReadCommittedIsolation |
|
| 2.5;2.5 |
| 1 | package org.apache.ojb.otm.lock.isolation; | |
| 2 | ||
| 3 | /* Copyright 2003-2005 The Apache Software Foundation | |
| 4 | * | |
| 5 | * Licensed under the Apache License, Version 2.0 (the "License"); | |
| 6 | * you may not use this file except in compliance with the License. | |
| 7 | * You may obtain a copy of the License at | |
| 8 | * | |
| 9 | * http://www.apache.org/licenses/LICENSE-2.0 | |
| 10 | * | |
| 11 | * Unless required by applicable law or agreed to in writing, software | |
| 12 | * distributed under the License is distributed on an "AS IS" BASIS, | |
| 13 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. | |
| 14 | * See the License for the specific language governing permissions and | |
| 15 | * limitations under the License. | |
| 16 | */ | |
| 17 | ||
| 18 | import org.apache.ojb.otm.core.Transaction; | |
| 19 | import org.apache.ojb.otm.lock.LockingException; | |
| 20 | import org.apache.ojb.otm.lock.ObjectLock; | |
| 21 | ||
| 22 | /** | |
| 23 | * | |
| 24 | * READ_COMMITTED IsolationStrategy. | |
| 25 | * | |
| 26 | * @author <a href="mailto:rraghuram@hotmail.com">Raghu Rajah</a> | |
| 27 | * @author Thomas Mahler & David Dixon-Peugh | |
| 28 | * | |
| 29 | */ | |
| 30 | public class ReadCommittedIsolation extends AbstractIsolation | |
| 31 | { | |
| 32 | ||
| 33 | /** | |
| 34 | * @see org.apache.ojb.otm.lock.TransactionIsolation#readLock(Transaction, ObjectLocks) | |
| 35 | */ | |
| 36 | public void readLock(Transaction tx, ObjectLock lock) | |
| 37 | throws LockingException | |
| 38 | { | |
| 39 | Transaction writer = lock.getWriter(); | |
| 40 | if (writer == null) | |
| 41 | { | |
| 42 | lock.readLock(tx); | |
| 43 | if (lock.getWriter() != null) | |
| 44 | { | |
| 45 | lock.releaseLock(tx); | |
| 46 | readLock(tx, lock); | |
| 47 | } | |
| 48 | } | |
| 49 | else if (tx != writer) | |
| 50 | { | |
| 51 | lock.waitForTx(writer); | |
| 52 | readLock(tx, lock); | |
| 53 | } | |
| 54 | // else if tx is the writer, it can also read. | |
| 55 | } | |
| 56 | ||
| 57 | /** | |
| 58 | * @see org.apache.ojb.otm.lock.TransactionIsolation#writeLock(Transaction, ObjectLocks) | |
| 59 | */ | |
| 60 | public void writeLock(Transaction tx, ObjectLock lock) | |
| 61 | throws LockingException | |
| 62 | { | |
| 63 | lock.writeLock(tx); | |
| 64 | } | |
| 65 | ||
| 66 | } |