java.lang.Error: Cleaner terminated abnormally

[Brian]

I've been having some trouble with BTrees on java6 and was wondering if anyone else was having similar issues.  Looking through the mailing lists, it looks like java 7 is preferred, but I don't see where that's marked as a hard requirement.  It looks like the bug has been fixed in java 7: http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=4938372.  The problem also seems to go away if I turn off transactions.  Posting to the mailing lists first in case this is really just user error or an incompatibility rather than a bug in mapDB.

Oracle jdk 1.6.0_31 running on Win7.

Test code:

import java.io.DataInputStream;
import java.io.File;
import java.io.IOException;
import java.net.URL;
import java.net.URLConnection;

import org.mapdb.BTreeMap;
import org.mapdb.DB;
import org.mapdb.DBMaker;

public class Test
{

    public static void main(String[] args) throws IOException {
        URLConnection conn = new URL("http://www.mapdb.org").openConnection();
        DataInputStream is = new DataInputStream(conn.getInputStream());
        int avail = is.available();
        byte[] bytes = new byte[avail];
        String data = null;
        try {
            is.readFully(bytes);
            System.out.println(bytes.length);
            data = new String(bytes);
        }
        finally {
            is.close();
        }
        int tCnt = 0;

        DB db = DBMaker.newFileDB(new File("C:\\data\\play\\test")).make();
        BTreeMap<Object, Object> map = db.getTreeMap("foo");
        for (int i = 0; i < 3000000; i++) {
            map.put(tCnt, data);
            if (tCnt % 10000 == 0) {
                System.out.println(tCnt);
                db.commit();
            }
            tCnt++;
        }
        db.commit();
        db.close();

    }
}

And the error I see:

java.lang.Error: Cleaner terminated abnormally
    at sun.misc.Cleaner$1.run(Cleaner.java:130)
    at java.security.AccessController.doPrivileged(Native Method)
    at sun.misc.Cleaner.clean(Cleaner.java:127)
    at java.lang.ref.Reference$ReferenceHandler.run(Reference.java:124)
Caused by: java.io.IOException: The process cannot access the file because another process has locked a portion of the file
    at sun.nio.ch.FileChannelImpl.unmap0(Native Method)
    at sun.nio.ch.FileChannelImpl.access$100(FileChannelImpl.java:32)
    at sun.nio.ch.FileChannelImpl$Unmapper.run(FileChannelImpl.java:667)
    at sun.misc.Cleaner.clean(Cleaner.java:125)
    ... 1 more

[Jan Kotek]

HI Brian,

 

MapDB should work with Java 6 and Windows, so this is bug which should be at least documented.

 

We had lot of problems with file locking on windows. There was a bug in write-ahead-log which was causing similar issue (please check you are using latest version or even current snapshot).

 

Other solution is to enable Random Access File, but it is much slower than mmaped files.

 

I created a bug for this issue:

https://github.com/jankotek/MapDB/issues/252

 

Jan