4089 - IceGrid database corruption.

3 files changed, 201 insertions, 2 deletions

diff --git a/java/src/Freeze/SharedDbEnv.java b/java/src/Freeze/SharedDbEnv.java
index b39088ec48f..e9747b1894b 100644
--- a/java/src/Freeze/SharedDbEnv.java
+++ b/java/src/Freeze/SharedDbEnv.java
@@ -271,6 +271,9 @@ public class SharedDbEnv implements com.sleepycat.db.ErrorHandler, Runnable
         Ice.Properties properties = key.communicator.getProperties();
         _trace = properties.getPropertyAsInt("Freeze.Trace.DbEnv");
 
+        String propertyPrefix = "Freeze.DbEnv." + _key.envName;
+        String dbHome = properties.getPropertyWithDefault(propertyPrefix + ".DbHome", _key.envName);
+        _fileLock = new IceUtilInternal.FileLock(dbHome + "/Freeze.lock");
         try
         {
             if(_ownDbEnv)
@@ -289,7 +292,6 @@ public class SharedDbEnv implements com.sleepycat.db.ErrorHandler, Runnable
                 //
                 config.setLockDetectMode(com.sleepycat.db.LockDetectMode.YOUNGEST);
 
-                String propertyPrefix = "Freeze.DbEnv." + _key.envName;
                 if(properties.getPropertyAsInt(propertyPrefix + ".DbRecoverFatal") != 0)
                 {
                     config.setRunFatalRecovery(true);
@@ -317,7 +319,6 @@ public class SharedDbEnv implements com.sleepycat.db.ErrorHandler, Runnable
 
                 try
                 {
-                    String dbHome = properties.getPropertyWithDefault(propertyPrefix + ".DbHome", _key.envName);
                     java.io.File home = new java.io.File(dbHome);
                     _dbEnv = new com.sleepycat.db.Environment(home, config);
                 }
@@ -465,6 +466,14 @@ public class SharedDbEnv implements com.sleepycat.db.ErrorHandler, Runnable
                 _dbEnv = null;
             }
         }
+
+        //
+        // Release the file lock
+        //
+        if(_fileLock != null)
+        {
+            _fileLock.release();
+        }
     }
 
     private static String
@@ -524,4 +533,6 @@ public class SharedDbEnv implements com.sleepycat.db.ErrorHandler, Runnable
     private java.util.Map<String, MapDb> _sharedDbMap = new java.util.HashMap<String, MapDb>();
 
     private static java.util.Map<MapKey, SharedDbEnv> _map = new java.util.HashMap<MapKey, SharedDbEnv>();
+
+    private IceUtilInternal.FileLock _fileLock;
 }
diff --git a/java/src/IceUtil/FileLockException.java b/java/src/IceUtil/FileLockException.java
new file mode 100644
index 00000000000..edef0f5da76
--- /dev/null
+++ b/java/src/IceUtil/FileLockException.java
@@ -0,0 +1,53 @@
+// **********************************************************************
+//
+// Copyright (c) 2003-2009 ZeroC, Inc. All rights reserved.
+//
+// This copy of Ice is licensed to you under the terms described in the
+// ICE_LICENSE file included in this distribution.
+//
+// **********************************************************************
+
+package IceUtil;
+
+public class FileLockException extends RuntimeException implements Cloneable
+{
+    public FileLockException(String path)
+    {
+        this.path = path;
+    }
+    public java.lang.Object clone()
+    {
+        java.lang.Object o = null;
+        try
+        {
+            o = super.clone();
+        }
+        catch(CloneNotSupportedException ex)
+        {
+            assert false; // Impossible
+        }
+        return o;
+    }
+
+    public String
+    ice_name()
+    {
+        return "IceUtil::FileLockException";
+    }
+
+    public String
+    toString()
+    {
+        java.io.StringWriter sw = new java.io.StringWriter();
+        java.io.PrintWriter pw = new java.io.PrintWriter(sw);
+        IceUtilInternal.OutputBase out = new IceUtilInternal.OutputBase(pw);
+        out.setUseTab(false);
+        out.print(getClass().getName());
+        out.inc();
+        IceInternal.ValueWriter.write(this, out);
+        pw.flush();
+        return sw.toString();
+    }
+
+    public String path;
+}
diff --git a/java/src/IceUtilInternal/FileLock.java b/java/src/IceUtilInternal/FileLock.java
new file mode 100644
index 00000000000..46f167ee986
--- /dev/null
+++ b/java/src/IceUtilInternal/FileLock.java
@@ -0,0 +1,135 @@
+// **********************************************************************
+//
+// Copyright (c) 2003-2009 ZeroC, Inc. All rights reserved.
+//
+// This copy of Ice is licensed to you under the terms described in the
+// ICE_LICENSE file included in this distribution.
+//
+// **********************************************************************
+
+package IceUtilInternal;
+
+import java.io.File;
+import java.io.RandomAccessFile;
+import java.io.FileWriter;
+import java.nio.channels.FileChannel;
+import java.nio.channels.OverlappingFileLockException;
+import java.lang.management.ManagementFactory;
+
+public final class FileLock
+{
+    //
+    // The constructor opens the given file (eventually creating it)
+    // and acquires a lock on the file or throws FileLockException if
+    // the file couldn't be locked.
+    //
+    // If the lock can be acquired, the Java VM name is written to the
+    // file.
+    //
+    public FileLock(String path)
+    {
+        _file = new File(path);
+
+        FileChannel channel;
+        try
+        {
+            _randFile = new RandomAccessFile(_file, "rw");
+            channel = _randFile.getChannel();
+        }
+        catch(java.io.FileNotFoundException e)
+        {
+            throw new IceUtil.FileLockException(path);
+        }
+        
+        java.nio.channels.FileLock lock;
+        try
+        {
+            lock = channel.tryLock();
+        }
+        catch(Exception ex)
+        {
+            IceUtil.FileLockException fe = new IceUtil.FileLockException(path);
+            fe.initCause(ex);
+            throw fe;
+        }
+        
+        if(lock == null)
+        {
+            throw new IceUtil.FileLockException(path);
+        }
+
+        //
+        // In Windows we don't write the process pid to the file, as is  not posible
+        // to read the file from other process while it is locked here.
+        //
+        if(!System.getProperty("os.name").startsWith("Windows"))
+        {
+            try
+            {
+                //
+                // Java doesn't provide get pid operation. This code
+                // writes the Java VM name instead of the pid.
+                //
+                // The output is JVM dependent. With the Sun
+                // implementation it's `pid@hostname'
+                //
+                _randFile.writeUTF(ManagementFactory.getRuntimeMXBean().getName());
+
+                //
+                // Don't close _randFile here or the lock will be released. It is called
+                // during release see comments there.
+                //
+            }
+            catch(java.io.IOException ex)
+            {
+                release();
+                throw new IceUtil.FileLockException(path);
+            }
+        }
+    }
+
+    //
+    // Remove the lock if it is owned by the class instance.
+    //
+    public void release()
+    {
+        if(System.getProperty("os.name").startsWith("Windows"))
+        {
+            if(_randFile != null)
+            {
+                //
+                // In Windows we need to close the file handler before
+                // we try to delete the file. Note that the call to close
+                // also release the file lock.
+                //
+                try
+                {
+                    _randFile.close();
+                }
+                catch(java.io.IOException ex)
+                {
+                }
+                _randFile = null;
+            }
+        }
+        //
+        // on UNIX the call to delete remove the file and that
+        // release the lock.
+        //
+        // In Windows the call to delete will success if at that point
+        // the file has not been opened by any process.
+        //
+        if(_file != null)
+        {
+            _file.delete();
+            _file = null;
+        }
+    }
+
+    //
+    // We need to keep these refrences to delete the lock file during release
+    //
+    private File _file;
+    private RandomAccessFile _randFile;
+
+}