display transactionStart in JMX listSessions operation, useful for debugging…

display transactionStart in JMX listSessions operation, useful for debugging long-running transactions

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

@@ -488,6 +488,7 @@ public class Session extends SessionWithState {
             unlinkLobMap = null;
         }
         unlockAll();
+        transactionStart = 0;
     }
 
     private void checkCommitRollback() {
@@ -516,6 +517,7 @@ public class Session extends SessionWithState {
             autoCommit = true;
             autoCommitAtTransactionEnd = false;
         }
+        transactionStart = 0;
     }
 
     /**
@@ -834,9 +836,6 @@ public class Session extends SessionWithState {
      * Wait for some time if this session is throttled (slowed down).
      */
     public void throttle() {
-        if (currentCommandStart == 0) {
-            currentCommandStart = System.currentTimeMillis();
-        }
         if (throttle == 0) {
             return;
         }
@@ -860,10 +859,14 @@ public class Session extends SessionWithState {
      */
     public void setCurrentCommand(Command command) {
         this.currentCommand = command;
-        if (queryTimeout > 0 && command != null) {
+        if (command != null) {
             long now = System.currentTimeMillis();
             currentCommandStart = now;
-            cancelAt = now + queryTimeout;
+            if (queryTimeout > 0) {
+                cancelAt = now + queryTimeout;
+            }
+        } else {
+            currentCommandStart = 0;
         }
     }
 
@@ -1054,6 +1057,7 @@ public class Session extends SessionWithState {
     public void begin() {
         autoCommitAtTransactionEnd = true;
         autoCommit = false;
+        transactionStart = System.currentTimeMillis();
     }
 
     public long getSessionStart() {
@@ -1061,9 +1065,6 @@ public class Session extends SessionWithState {
     }
 
     public long getTransactionStart() {
-        if (transactionStart == 0) {
-            transactionStart = System.currentTimeMillis();
-        }
         return transactionStart;
     }
 

h2/src/main/org/h2/jmx/DatabaseInfo.java

@@ -175,14 +175,17 @@ public class DatabaseInfo implements DatabaseInfoMBean {
         StringBuilder buff = new StringBuilder();
         for (Session session : database.getSessions(false)) {
             buff.append("session id: ").append(session.getId());
-            buff.append(" user: ").append(session.getUser().getName()).append('\n');
-            buff.append("connected: ").append(new Timestamp(session.getSessionStart())).append('\n');
+            buff.append("\tuser: ").append(session.getUser().getName()).append('\n');
+            buff.append("\tconnected: ").append(new Timestamp(session.getSessionStart())).append('\n');
+            if (session.getTransactionStart() != 0) {
+                buff.append("\ttransactionStart: ").append(new Timestamp(session.getTransactionStart())).append('\n');
+            }
             Command command = session.getCurrentCommand();
             if (command != null) {
-                buff.append("statement: ").append(session.getCurrentCommand()).append('\n');
+                buff.append("\tstatement: ").append(session.getCurrentCommand()).append('\n');
                 long commandStart = session.getCurrentCommandStart();
                 if (commandStart != 0) {
-                    buff.append("started: ").append(new Timestamp(commandStart)).append('\n');
+                    buff.append("\tstarted: ").append(new Timestamp(commandStart)).append('\n');
                 }
             }
             Table[] t = session.getLocks();

h2/src/test/org/h2/test/unit/TestJmx.java

@@ -8,10 +8,14 @@ package org.h2.test.unit;
 
 import java.lang.management.ManagementFactory;
 import java.sql.Connection;
+import java.sql.SQLException;
 import java.sql.Statement;
 import java.util.HashMap;
 import java.util.Set;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.TimeUnit;
 import javax.management.Attribute;
+import javax.management.JMException;
 import javax.management.MBeanAttributeInfo;
 import javax.management.MBeanInfo;
 import javax.management.MBeanOperationInfo;
@@ -34,8 +38,12 @@ public class TestJmx extends TestBase {
         TestBase.createCaller().init().test();
     }
 
-    @SuppressWarnings("unchecked")
     public void test() throws Exception {
+        testJMX();
+        testTransactionsInProgress();
+    }
+    
+    private void testJMX() throws Exception {
         HashMap<String, MBeanAttributeInfo> attrMap;
         HashMap<String, MBeanOperationInfo> opMap;
         String result;
@@ -104,8 +112,8 @@ public class TestJmx extends TestBase {
         conn = getConnection("jmx;jmx=true");
 
         name = new ObjectName("org.h2:name=JMX,*");
-        Set set = mbeanServer.queryNames(name, null);
-        name = (ObjectName) set.iterator().next();
+        Set<ObjectName> set = mbeanServer.queryNames(name, null);
+        name = set.iterator().next();
 
         assertEquals("16384", mbeanServer.getAttribute(name, "CacheSizeMax").toString());
         mbeanServer.setAttribute(name, new Attribute("CacheSizeMax", 1));
@@ -122,4 +130,34 @@ public class TestJmx extends TestBase {
 
     }
 
+    private void testTransactionsInProgress() throws SQLException, InterruptedException, JMException, NullPointerException {
+        MBeanServer mbeanServer = ManagementFactory.getPlatformMBeanServer();
+        ObjectName name = new ObjectName("org.h2:name=JMX,path=mem_jmx");
+        
+        deleteDb("jmx");
+        final Connection conn = getConnection("mem:jmx;jmx=true");
+        final CountDownLatch latch = new CountDownLatch(1);
+        
+        new Thread("TestJmx,sleep") {
+            public void run() {
+                try {
+                    conn.setAutoCommit(false);
+                    Statement stat = conn.createStatement();
+                    stat.execute("CREATE ALIAS sleep FOR \"java.lang.Thread.sleep\"");
+                    stat.execute("begin");
+                    latch.countDown();
+                    stat.execute("call sleep(2000)");
+                } catch (SQLException ex) {}
+            }
+        }.start();
+
+        latch.await(2000, TimeUnit.MILLISECONDS);
+        Thread.sleep(200);
+        
+        String result = mbeanServer.invoke(name, "listSessions", null, null).toString();
+        assertTrue(result.indexOf("transactionStart:") >= 0);
+        assertTrue(result.indexOf("call sleep") >= 0);
+        
+        conn.close();
+    }
 }