Apache
/
activemq
mirror of https://github.com/apache/activemq.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

updated fix: https://issues.apache.org/jira/browse/AMQ-3982 

Instead of locking on the PList iterator which forces a lock on every access to hasNext we should lock down at the PageFile level in readPage making the seek and read an atomic operation.  Since many reads on a single already loaded page don't need to be synchronized we pay a higher price for locking in the specific PList case than we do buy creating this atomic read operation in PageFile. 

git-svn-id: https://svn.apache.org/repos/asf/activemq/trunk@1375852 13f79535-47bb-0310-9956-ffa450edef68
This commit is contained in:
Timothy A. Bish 2012-08-21 23:28:50 +00:00
parent ba9037ca65
commit 4bace216b9
2 changed files with 12 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
activemq-core/src/main/java/org/apache/activemq/store/kahadb/plist/PList.java
View File

@ -202,9 +202,7 @@ public class PList extends ListIndex<String, Location> {
@Override
public boolean hasNext() {
synchronized (indexLock) {
return iterator.hasNext();
}
return iterator.hasNext();
}
@Override

13
kahadb/src/main/java/org/apache/kahadb/page/PageFile.java
View File

@ -16,7 +16,16 @@
*/
package org.apache.kahadb.page;
import java.io.*;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InterruptedIOException;
import java.io.RandomAccessFile;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
@ -862,7 +871,7 @@ public class PageFile {
return nextTxid.incrementAndGet();
}
void readPage(long pageId, byte[] data) throws IOException {
synchronized void readPage(long pageId, byte[] data) throws IOException {
readFile.seek(toOffset(pageId));
readFile.readFully(data);
}