<li>Issue #255: ConcurrentModificationException with multiple threads in…

<li>Issue #255: ConcurrentModificationException with multiple threads in embedded mode and temporary LOBs

I think I've fixed this

h2/src/docsrc/html/changelog.html

@@ -21,6 +21,8 @@ Change Log
 
 <h2>Next Version (unreleased)</h2>
 <ul>
+<li>Issue #255: ConcurrentModificationException with multiple threads in embedded mode and temporary LOBs
+</li>
 <li>Issue #235: Anonymous SSL connections fail in many situations
 </li>
 <li>Fix race condition in FILE_LOCK=SOCKET, which could result in the watchdog thread not running  

h2/src/main/org/h2/engine/Engine.java

@@ -6,7 +6,6 @@
 package org.h2.engine;
 
 import java.util.HashMap;
-
 import org.h2.api.ErrorCode;
 import org.h2.command.CommandInterface;
 import org.h2.command.Parser;
@@ -189,6 +188,7 @@ public class Engine implements SessionFactory {
                 // ignore
             }
         }
+        synchronized (session) {
             session.setAllowLiterals(true);
             DbSettings defaultSettings = DbSettings.getDefaultSettings();
             for (String setting : ci.getKeys()) {
@@ -229,6 +229,7 @@ public class Engine implements SessionFactory {
             }
             session.setAllowLiterals(false);
             session.commit(true);
+        }
         return session;
     }
 

h2/src/main/org/h2/engine/Session.java

@@ -649,6 +649,11 @@ public class Session extends SessionWithState {
     }
 
     private void removeTemporaryLobs(boolean onTimeout) {
+        if (SysProperties.CHECK2) {
+            if (!Thread.holdsLock(this) && !Thread.holdsLock(getDatabase())) {
+                throw DbException.throwInternalError();
+            }
+        }
         if (temporaryLobs != null) {
             for (Value v : temporaryLobs) {
                 if (!v.isLinkedToTable()) {

h2/src/main/org/h2/engine/SessionRemote.java

@@ -581,7 +581,9 @@ public class SessionRemote extends SessionWithState implements DataHandler {
         }
         traceSystem.close();
         if (embedded != null) {
+            synchronized (embedded) {
                 embedded.close();
+            }
             embedded = null;
         }
         if (closeError != null) {

h2/src/main/org/h2/server/TcpServerThread.java

@@ -14,7 +14,6 @@ import java.io.StringWriter;
 import java.net.Socket;
 import java.sql.SQLException;
 import java.util.ArrayList;
-
 import org.h2.api.ErrorCode;
 import org.h2.command.Command;
 import org.h2.engine.ConnectionInfo;
@@ -182,7 +181,9 @@ public class TcpServerThread implements Runnable {
                 server.traceError(e);
             }
             try {
+                synchronized (session) {
                     session.close();
+                }
                 server.removeConnection(threadId);
             } catch (RuntimeException e) {
                 if (closeError == null) {