[jbosscache-commits] JBoss Cache SVN: r6802 - in core/branches/2.2.X/src/main/java/org/jboss/cache: lock and 1 other directories.
jbosscache-commits at lists.jboss.org
jbosscache-commits at lists.jboss.org
Fri Sep 26 07:28:53 EDT 2008
Author: manik.surtani at jboss.com
Date: 2008-09-26 07:28:53 -0400 (Fri, 26 Sep 2008)
New Revision: 6802
Removed:
core/branches/2.2.X/src/main/java/org/jboss/cache/util/concurrent/locks/
Modified:
core/branches/2.2.X/src/main/java/org/jboss/cache/loader/AdjListJDBCCacheLoader.java
core/branches/2.2.X/src/main/java/org/jboss/cache/loader/AdjListJDBCCacheLoaderConfig.java
core/branches/2.2.X/src/main/java/org/jboss/cache/loader/JDBCCacheLoader.java
core/branches/2.2.X/src/main/java/org/jboss/cache/loader/JDBCCacheLoaderOld.java
core/branches/2.2.X/src/main/java/org/jboss/cache/lock/StripedLock.java
Log:
Better impl for JBCACHE-1410: JDBCCacheLoader may attempt to create a node entry in the DB twice
Modified: core/branches/2.2.X/src/main/java/org/jboss/cache/loader/AdjListJDBCCacheLoader.java
===================================================================
--- core/branches/2.2.X/src/main/java/org/jboss/cache/loader/AdjListJDBCCacheLoader.java 2008-09-26 11:20:35 UTC (rev 6801)
+++ core/branches/2.2.X/src/main/java/org/jboss/cache/loader/AdjListJDBCCacheLoader.java 2008-09-26 11:28:53 UTC (rev 6802)
@@ -243,8 +243,46 @@
safeClose(st);
cf.close(con);
}
+
+ createDummyTableIfNeeded();
}
+ private void createDummyTableIfNeeded() throws Exception
+ {
+ Connection conn = null;
+ PreparedStatement ps = null;
+ try
+ {
+ conn = cf.getConnection();
+ ps = conn.prepareStatement(config.getDummyTableRemovalDDL());
+ ps.execute();
+ }
+ catch (Exception e)
+ {
+ // ignore - it just means we didn't need to drop any database tables.
+ }
+ finally
+ {
+ safeClose(ps);
+ cf.close(conn);
+ }
+
+ try
+ {
+ conn = cf.getConnection();
+ ps = conn.prepareStatement(config.getDummyTableCreationDDL());
+ ps.execute();
+ safeClose(ps);
+ ps = conn.prepareStatement(config.getDummyTablePopulationSql());
+ ps.execute();
+ }
+ finally
+ {
+ safeClose(ps);
+ cf.close(conn);
+ }
+ }
+
@Override
public void stop()
{
@@ -411,10 +449,11 @@
/**
* Inserts a node into the database
*
- * @param name the fqn
- * @param node the node
+ * @param name the fqn
+ * @param node the node
+ * @param rowMayExist if true, then this method will not be strict in testing for 1 row being inserted, since 0 may be inserted if the row already exists.
*/
- protected void insertNode(Fqn name, Map node)
+ protected void insertNode(Fqn name, Map node, boolean rowMayExist)
{
Connection con = null;
PreparedStatement ps = null;
@@ -428,8 +467,12 @@
con = cf.getConnection();
ps = con.prepareStatement(config.getInsertNodeSql());
- ps.setString(1, name.toString());
+ String fqnString = name.toString();
+ // the Fqn needs to be in the 1st and 4th places.
+ ps.setString(1, fqnString);
+ ps.setString(4, fqnString);
+
if (node != null)
{
// ByteArrayOutputStream baos = new ByteArrayOutputStream();
@@ -465,7 +508,7 @@
}
int rows = ps.executeUpdate();
- if (rows != 1)
+ if (!rowMayExist && rows != 1)
{
throw new IllegalStateException("Expected one insert row but got " + rows);
}
Modified: core/branches/2.2.X/src/main/java/org/jboss/cache/loader/AdjListJDBCCacheLoaderConfig.java
===================================================================
--- core/branches/2.2.X/src/main/java/org/jboss/cache/loader/AdjListJDBCCacheLoaderConfig.java 2008-09-26 11:20:35 UTC (rev 6801)
+++ core/branches/2.2.X/src/main/java/org/jboss/cache/loader/AdjListJDBCCacheLoaderConfig.java 2008-09-26 11:28:53 UTC (rev 6802)
@@ -579,14 +579,44 @@
private String constructInsertNodeSql()
{
- return "insert into " +
- table +
- " (" +
- fqnColumn +
- ", " +
- nodeColumn +
- ", " +
- parentColumn +
- ") values (?, ?, ?)";
+ // This SQL string takes in 4 params - fqn, node (serialized data), parent, and fqn AGAIN.
+ // the benefit of this is is that it will run without failing even if the row already exists, so you don't need
+ // to check if the row exists before running this query. Returns '1' if the row was inserted, '0' otherwise,
+ // but does NOT fail on primary key conflict.
+
+ // the 'dummy' table, table_D, *must* exist though, and could contain just a single dummy constant row.
+
+ return "INSERT INTO "
+ + table
+ + " ("
+ + fqnColumn
+ + ", "
+ + nodeColumn
+ + ", "
+ + parentColumn
+ + ") SELECT ?, ?, ? FROM "
+ + table
+ + "_D WHERE NOT EXISTS (SELECT "
+ + fqnColumn
+ + " FROM "
+ + table
+ + " WHERE "
+ + fqnColumn
+ + " = ?)";
}
+
+ public String getDummyTableCreationDDL()
+ {
+ return "create table " + table + "_D (i CHAR)";
+ }
+
+ public String getDummyTableRemovalDDL()
+ {
+ return "drop table " + table + "_D";
+ }
+
+ public String getDummyTablePopulationSql()
+ {
+ return "insert into " + table + "_D values ('x')";
+ }
}
\ No newline at end of file
Modified: core/branches/2.2.X/src/main/java/org/jboss/cache/loader/JDBCCacheLoader.java
===================================================================
--- core/branches/2.2.X/src/main/java/org/jboss/cache/loader/JDBCCacheLoader.java 2008-09-26 11:20:35 UTC (rev 6801)
+++ core/branches/2.2.X/src/main/java/org/jboss/cache/loader/JDBCCacheLoader.java 2008-09-26 11:28:53 UTC (rev 6802)
@@ -240,21 +240,13 @@
Fqn currentNode = name;
do
{
- try
+ if (currentNode.equals(name))
{
- lock.acquireLock(currentNode, true);
- if (currentNode.equals(name))
- {
- insertNode(currentNode, attributes);
- }
- else
- {
- if (loadNode(currentNode) == null) insertNode(currentNode, null);
- }
+ insertNode(currentNode, attributes, false);
}
- finally
+ else
{
- lock.releaseLock(currentNode);
+ insertNode(currentNode, null, true);
}
if (currentNode.isRoot()) break;
currentNode = currentNode.getParent();
Modified: core/branches/2.2.X/src/main/java/org/jboss/cache/loader/JDBCCacheLoaderOld.java
===================================================================
--- core/branches/2.2.X/src/main/java/org/jboss/cache/loader/JDBCCacheLoaderOld.java 2008-09-26 11:20:35 UTC (rev 6801)
+++ core/branches/2.2.X/src/main/java/org/jboss/cache/loader/JDBCCacheLoaderOld.java 2008-09-26 11:28:53 UTC (rev 6802)
@@ -135,11 +135,11 @@
final Fqn parent = name.getAncestor(i);
if (!exists(parent))
{
- insertNode(parent, null);
+ insertNode(parent, null, false);
}
}
}
- insertNode(name, node);
+ insertNode(name, node, false);
}
return oldValue;
@@ -317,11 +317,11 @@
final Fqn parent = name.getAncestor(i);
if (!exists(parent))
{
- insertNode(parent, null);
+ insertNode(parent, null, false);
}
}
}
- insertNode(name, attrs);
+ insertNode(name, attrs, false);
}
}
}
Modified: core/branches/2.2.X/src/main/java/org/jboss/cache/lock/StripedLock.java
===================================================================
--- core/branches/2.2.X/src/main/java/org/jboss/cache/lock/StripedLock.java 2008-09-26 11:20:35 UTC (rev 6801)
+++ core/branches/2.2.X/src/main/java/org/jboss/cache/lock/StripedLock.java 2008-09-26 11:28:53 UTC (rev 6802)
@@ -23,9 +23,9 @@
import net.jcip.annotations.ThreadSafe;
import org.jboss.cache.Fqn;
-import org.jboss.cache.util.concurrent.locks.UpgradableLock;
import java.util.List;
+import java.util.concurrent.locks.ReentrantReadWriteLock;
/**
* A simple implementation of lock striping, using Fqns as the keys to lock on, primarily used to help make
@@ -48,7 +48,7 @@
private final int lockSegmentMask;
private final int lockSegmentShift;
- final UpgradableLock[] sharedLocks;
+ final ReentrantReadWriteLock[] sharedLocks;
/**
* This constructor just calls {@link #StripedLock(int)} with a default concurrency value of 20.
@@ -75,9 +75,9 @@
lockSegmentShift = 32 - tempLockSegShift;
lockSegmentMask = numLocks - 1;
- sharedLocks = new UpgradableLock[numLocks];
+ sharedLocks = new ReentrantReadWriteLock[numLocks];
- for (int i = 0; i < numLocks; i++) sharedLocks[i] = new UpgradableLock();
+ for (int i = 0; i < numLocks; i++) sharedLocks[i] = new ReentrantReadWriteLock();
}
/**
@@ -88,11 +88,11 @@
*/
public void acquireLock(Fqn fqn, boolean exclusive)
{
- UpgradableLock lock = getLock(fqn);
+ ReentrantReadWriteLock lock = getLock(fqn);
if (exclusive)
{
- lock.acquireWriteLockWithUpgrade();
+ lock.writeLock().lock();
}
else
{
@@ -107,11 +107,18 @@
*/
public void releaseLock(Fqn fqn)
{
- UpgradableLock lock = getLock(fqn);
- lock.unlock();
+ ReentrantReadWriteLock lock = getLock(fqn);
+ if (lock.isWriteLockedByCurrentThread())
+ {
+ lock.writeLock().unlock();
+ }
+ else
+ {
+ lock.readLock().unlock();
+ }
}
- final UpgradableLock getLock(Object o)
+ final ReentrantReadWriteLock getLock(Object o)
{
return sharedLocks[hashToIndex(o)];
}
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